M u t i c a r i a

Horticultural Wednesday I

2012-01-18T16:14:00.000+01:00

Phalaenopsis is a very popular orchid genus originating from southeast Asia, with several horticultural varieties. The fine specimen above was photographed in Puerto de la Cruz, in Tenerife.

Entomological Society of Malta - vol. 4 launch

2012-01-17T18:38:00.000+01:00

Last Friday saw the launch of the 4th volume of ESM's excellent series of papers dealing with, as the name of the society implies, the entomology of the Maltese islands and their biogeographic context.

The event was held under the patronage of His Excellency Dr. George Abela, and three society members (including its chairman) delivered short speeches on the importance of scientific research, peer reviews, funding and the maintenance of high publication standards.

The scope of the talks ranged from the general, all-encompassing importance of works by luminaries such as Max Planck and Thomas Kuhn, to the specialized methodologies employed by scientists dealing in what the public may perceive as the "dinja stramba ta' dud, nemel u nsetti oħra" (lit. strange world of bugs, ants and other insects).

On to the main issue at hand - and its contents. This collection contains:

1) a catalogue of the aphid species occurring in Malta, with 48 new records, together with a list of aphid parasitoids, with three new records, and a new record of a coccid

2) observations and records of tachinid, rhinophorid and cecidomyiid flies from Malta and other Mediterranean areas

3) observations and records of nepticulid and pyralid moths from Malta

4) a catalogue of Maltese Scarabeoidea with eight new records, with a discussion on possible extinction mechanisms for these very interesting beetles

5) short features aimed at the younger demographic

A sample illustration - Scarabaeus (Ateuchetus) semipunctatus Fabricius, 1792 and Scarabaeus (Ateuchetus) variolosus Fabricius, 1787

The website was not updated in time for the launch, therefore for more information on the society please contact

Dr. David Mifsud
Entomological Society of Malta
P. O. Box 9
Marsa, MRS1000
Malta

Wordplay

2012-01-17T14:02:00.000+01:00

The tag cloud generated by the local html programming on blogspot.com invariably translates to the drab affair shown below, copied and pasted from my own blog.

On the other hand, custom-built generators such as wordle.com allow users to tweak fonts and designs according to personal taste (or lack thereof) to achieve far more interesting, attention-grabbing layouts. Here's one I finished earlier, in true pop-art abandon (click on image for a larger view).

Death of a Phoenix

2012-01-12T21:26:00.000+01:00

Palms are a common sight in Malta, with the warm temperatures affecting the islands throughout most of the year being a perfect catalyst for their growth and proliferation. This said, indigenous species amount to just one - the low-growing, bushy Chamaerops humilis L., now practically extinct in the wild.

Chamaerops humilis L., photographed by Aron Tanti

The recent invasion of the red palm weevil Rhynchophorus ferrugineus (Olivier, 1790) has affected several of the ornamental palms of the genus Phoenix.

Rhynchophorus ferrugineus (Olivier, 1790) from www.cm-oaz.pt

The date palm, Phoenix dactylifera L., is a historically important North African species that may be distinguished by leaves arranged in wide silvery fronds. The picture beneath shows this species of palm affected by the Rhynchophorus beetle.

Phoenix dactylifera L. affected by the red palm weevil in Santa Venera, Malta

Phoenix sp. in Rome, Italy, with the one on the right showing symptoms of red palm weevil infestation

Phoenix canariensis Chabaud is a Canarian endemic which is frequently planted around the Mediterranean, not least in Malta. Unfortunately it is also affected by the weevil in question and several stately specimens from around the island have been destroyed.

Phoenix canariensis Chabaud in the main road of Floriana, Malta

The inhabitants of Tenerife certainly make excellent use of their endemic palm species!

Steno on Google

2012-01-11T11:13:00.001+01:00

The 374th anniversary of birth of the 'father of geology' Nicolaus Stensen, better known by his latinized name Nicolas Steno, is commemorated today on Google with a doodle showing a stylized stratigraphic section similar to what he may have encountered to come up with his conclusions.

Steno was featured on this blog together with his contemporary Agostino Scilla in a post from 2010.

Nature class

2011-10-10T23:23:00.004+02:00

Juniper, yew, spruce and other specimens with textbook shown below, for observation during a lesson. Photos taken at the Základní škola Lesní (an elementary school in Liberec, the Czech Republic).

The school logo is also a conifer, albeit a highly anthropomorphized version:

Field biology course for educators

2011-10-09T12:08:00.002+02:00

A group of 27 biology teachers from Church schools recently attended a week-long course in field biology jointly organised by the University’s Department of Biology and the Curia’s Secretariat for Education at the University.

The course was aimed at updating educators on methodology related to fieldwork organisation.

It is widely recognised that the teaching of biology is most enriching and interesting for students when the learning process takes place ‘outside the classroom’ and in a ‘real world’ setting.

The course consisted of lectures, fieldwork and laboratory sessions, with a focus on the Maltese environment. During the week, participants had the opportunity to put theoretical knowledge into practice through planning and preparation for fieldwork, surveying, sampling and data collection, and processing of the data collected.

Topics covered during the course were related to shore and terrestrial ecology.

During the shore ecology fieldwork, held on the Għallis coast, participants identified flora and fauna that inhabit rocky shores, and collected data on the abundance of selected fauna. During the terrestrial ecology fieldwork, held at Clapham Junction and Buskett, participants observed typical Mediterranean vegetation communities: garigue, steppe, maquis, and woodland.

The knowledge and applications learnt during the marine and terrestrial fieldwork sessions was synthesised during a site visit to Għajn Tuffieħa.

A variety of habitats was explored there, ranging from banquettes of Posidonia oceanica wrack deposited on the sandy beach, to the terrestrial boulder scree that constitutes the typical Maltese rdum habitat.

The lectures, field and laboratory sessions were led by Joseph Borg, Patrick Schembri and Sandro Lanfranco from the University’s Biology Department.

Originally published in The Sunday Times, 9.X.2011.

Ups and downs

2011-10-05T23:02:00.000+02:00

down by cable car from Ještěd, the highest mountain of the Czech Republic

stream in statek Ondříkovice, Frýdštejn, Czech Republic

conifers in Malá Skála, Czech Republic

Into the forests of Liberec

2011-10-03T15:43:00.000+02:00

Along a stream, dewdrops on a delicate horsetail (Equisetum sp.) capture sunlight, scattering it into a miniature forest buzzing with insect life, amongst which is the common yet striking Pyrrhocoris apterus (Linnaeus, 1758). This heteropteran frequently shows aggregating behaviour and is found large populations, here photographed on the bark of the Czech national tree Tilia cordata Mill.


Equisetum sp., Liberec, Czech Republic

Pyrrhocoris apterus (L., 1758) on Tilia cordata Mill.

The periphery of the forest is characterized by a colourful scatter of berry clusters belonging to rowan (Sorbus aucuparia L.) and elder (Sambucus nigra L.), both of which have been traditionally used for food and medicine by settlers all over Europe. Further into the forest, as shade and shelter become predominant, ferns and mosses cover most of the clearing and make use of the abundant leaf litter.

Sorbus aucuparia L.

Sambucus nigra L.

Ferns on the forest floor

Conifers of the area include pines (Pinus sylvestris L.) and spruce (Picea abies (L.) H.Karst), sometimes bearing evidence of food-seeking woodpeckers on their old trunks. Angiosperms such as beech (Fagus sylvatica L.) are also common, with their deceased offering an excellent resource for several fungal specimens.

seeds of Fagus sylvatica L.

Fagus sylvatica L. compost

fungus 1

fungus 2

clues left by woodpeckers

Nymphalis antiopa (Linnaeus, 1758) and Vanessa atalanta (Linnaeus, 1758) are two beautiful and conspicuous butterflies found within the forest and elsewhere.

Nymphalis antiopa (L., 1758)

Vanessa atalanta (L., 1758)

A dead specimen of the European slow-worm Anguis fragilis Linnaeus, 1758 was a surprising find, and one of the very few vertebrates making an appearance on the day.

Anguis fragilis L., 1758

Pesticide with a difference

2011-08-18T01:49:00.002+02:00

This is just what you need to kill sinister sinistrals and restore your snail population to one made up of normal, dextral pests.

Phillumenic conundrum

2011-08-12T14:55:00.000+02:00

Prior to this event I had never heard of the obscure hobby of phillumeny, but what should have been a casual glance inside an antiques shop in Santa Cruz necessitated some brushing up on the matter. I could not resist leaving this singular item to gather dust on a shelf unless that shelf was mine.

this is all I know about this set

A defunct (?) match factory in Las Palmas (capital city of Gran Canaria), Fosforera Canariense, produced this nice set of 24 matchboxes sometime last century after its foundation in 1935. Information regarding such items is hard to come by, on-and-offline, therefore not much more is known at this stage.

click on image for large version

The set is called Caracolas Marinas (marine snails) and features 24 species of molluscs (inexplicably consisting of one bivalve and 23 predominantly tropical, not-all-marine, gastropods) heavily inked onto a pale blue background. The way they are packaged makes it impossible to see what is on the hidden side of each matchbox, and where, presumably, the species identifications are printed.

click on image for large version

Now, I am sorely tempted to tear open the polythene covering holding the set together in order to read them; on the other hand, doing so will detract from the neatness and value of the boxed set. I'm a stickler for 'accurate' identification (as opposed to mere Cypraea, Murex, Lambis, Harpa, Conus, Architectonica, Mitra, Cymatium etc.) but these cardboard versions will have to remain a mystery, at least until curiosity gets the upper hand.

In trouble

2011-08-06T15:01:00.001+02:00


Butterfly pupa, with parasitic wasps. Aguamansa, Tenerife 2011.

Flowers on the volcano

2011-08-04T14:28:00.002+02:00

Following yesterday's journey we have now arrived close to the summit of El Teide. The landscape is a vast expanse of bleak volcanic rock, including obsidian, phonolite and trachyte, which form when lava solidifies according to different physico-chemical criteria.

El Teide volcano

Teide's most recent eruption dates back to 1909, and some tremors have been recorded in 2004, indicating a dormant volcano may become active in a few years' time.

El Teide's 1909 eruption, live (photo stolen from here)

In any case, the plants seem quite happy about their choice of habitat. A large number of endemic species characterize Tenerife and many of these species are abundant high above the pine forest. The southern side of the Teide, in the Las Cañadas caldera, is a habitat known as subalpine scrub, dominated by shrubs of the legume Spartocystus supranubius L., together with bushes of the beautiful Pterocephalus lasiospermum Link.

dark green shrubs of Spartocystus supranubius L., with Pterocephalus lasiospermus Link in the foreground

Spartocystus supranubius L. with seed-pods

Pterocephalus lasiospermus Link

flowers of Pterocephalus lasiospermus Link

Amongst these one can also find the very interesting Cheirolophus teydis (C.Sm.) G.López, an endemic plant of Teide that is a very close relation of Malta's national (and also endemic) plant, Cheirolophus crassifolius (Bertoloni). Unfortunately all plants were only on the verge of flowering during this visit. Flowers of C. teydis are pale yellowish.

Cheirolophus teydis (C.Sm.) G.López

Adenocarpus viscosus (Willd.) Webb & Berthel. and several species of Echium are also very characteristic inhabitants of El Teide, characterizing landscapes with their yellow flowers and tall spikes respectively.

Adenocarpus viscosus (Willd.) Webb & Berthel.

Echium sp.

Echium sp. flowers

lycaenid butterfly resting on Echium sp.

Above the clouds of El Teide

2011-08-04T01:03:00.000+02:00

The third largest volcano on earth (according to some sources, but not to others - it depends on how you go about measuring volcanoes) is found off West Africa, on Tenerife.

To see the majestic peak of this volcano, El Teide, one must traverse a height of about two kilometres of pine forest, dominated by the endemic Canarian pine Pinus canariensis C.Sm. This pine has developed an extraordinary way of utilizing the water available in the mist enveloping these forests - its leaves are tall and thin, allowing condensation of water droplets on their large surface area. This water trickles down, dropping into the soil and providing roots with much-needed hydration.

Pinus canariensis C.Sm., 2.5km up east El Teide

In some places, violent storms some years back have ripped the trees down, the trunks of which together with the flowing clouds produce an eerie atmosphere reminiscent of any horror film worth its salt:

wind-battered pine forest, c. 2km up east El Teide

After the ascent of about another kilometre one can see the forest spread below and a wide swathe of cloud enveloping it:

About 3km up El Teide, the volcano in the background

Coming up next: some local flora.

My first encounter with a Canarian dinosaur

2011-08-02T18:23:00.003+02:00

As soon as one starts travelling around Tenerife one starts becoming aware of a particular species of reptile populating much of its landscapes. The first things that struck me about this animal are its fairly large size (about 30cm in males) and its bold colouration, which are features by all means not unheard of in lizards (see here for an extinct Maltese giant lizard); however, being more accustomed to the smaller and much more agile Maltese Podarcis, I was surprised.

The lizards are also fearless and will venture very close to their human observers, especially if food is involved. They are endemic to Tenerife and belong to the species Gallotia galloti Oudart, 1839, which has differentiated into four subspecies around the same island and its neighbours. The ones in the following pictures are from the northern population of Gallotia galloti eisentrauti Bischoff, 1982 in Puerto de la Cruz, Tenerife.

It can be seen here that males are characterized by the larger size and a neon-blue throat, together with several other markings not found in females, which on the other hand are smaller and covered in brown patterns.

male specimen of Gallotia galloti eisentrauti Bischoff, 1982 basking in the sun


male Gallotia galloti eisentrauti Bischoff, 1982


		female Gallotia galloti eisentrauti Bischoff, 1982 on the alert

The other subspecies are Gallotia galloti galloti (Oudart, 1839) from southern Tenerife, Gallotia galloti insulanagae Martin, 1985, from the isolated and inaccessible island northeast of Tenerife (Roque de Fuera de Anaga), and Gallotia galloti palmae (Boettger & Müller, 1914) from the island of La Palma.

The lizards are also an icon of the Guanche (aboriginal/ pre-Hispanic) culture on Tenerife, with several depictions and rock carvings still existing and on show in museums. They also ensure a steady income from tourists, their (highly non-realistic) outlines being featured on everything from ashtrays to t-shirts (though I must admit I had to buy one of the latter).

Los Gigantes cliffs in Tenerife

2011-08-01T16:17:00.001+02:00

The highest cliffs in the volcanic island of Tenerife, in the Atlantic Ocean, are found on its western side. These majestic geological features are known as 'Los Gigantes' (the Giants), a term which perfectly befits their massive presence.

Acantilados de Los Gigantes, Tenerife

The cliffs are (like much of the island) composed of 'alkali' basalt, a volcanic rock which contains high proportions minerals like feldspar, olivine and iron oxides. These mineral accretions are sometimes large enough to be seen with the naked eye:

feldspar (white crystals) and iron oxides (brown aggregate) in basalt

olivine (greenish crystals) in basalt

The basalt is found in layers which are texturally highly varied, each layer indicating a different episode or process in the island's violent volcanic history. For example, the breccia-like ignimbrite forms when a stream of lava partly melts the substrate upon which it is flowing and drags the pieces of hot rock along, subsequently welding the fragments together into a pudding-like composition, in this case containing fragments of widely disparate size:

ignimbrite

Another rock which stands out visually is red ochre, which forms when hot lava passes over well-developed soils. It can be seen as a thin reddish line in the following photograph:

red ochre stratum

Over millions of years, boulders of basalt tumble down the cliffs and are rounded by wave and wind action.

boulders on the shore

As a rough habitat largely characterized by strong currents and abrasive basalt gravel, the interface between the sea and land is largely devoid of macrofauna, though some usual suspects make an appearance. Most notable of these are two Macaronesian endemics - the limpet Patella piperata Gould, 1846 and the periwinkle Littorina striata King & Broderip, 1832. Closer to mean sea level, Patella tenuis crenata d'Orbigny, 1840 makes an appearance. The third species of limpet that may be encountered on Tenerife is Patella ulyssiponensis Gmelin, 1791, though none of these were seen during this trip.

Littorina striata King & Broderip, 1832

Patella piperata Gould, 1846

Specimens of Osilinus sauciatus (Koch, 1845) were found in small clusters, mostly using deep cracks as shelter.

Osilinus sauciatus (Koch, 1845)

Some swimmers in Hyde Park

2011-07-12T14:12:00.001+02:00

Canada geese (Branta canadensis parvipes (Cassin, 1852)) coming closer to the photographer, hoping for scraps of food.

Eurasian coots (Fulica atra L., 1758) preening while a pigeon (Columba livia Gmelin, 1798) struts by.

Male mallard duck (Anas platyrhynchos L., 1758) taking it easy.

New marine biology papers

2011-05-21T17:37:00.002+02:00

1. Mifsud, C. & Cachia, C., 2011. New additions and corrections, with annotations, to the check-list of the marine Mollusca of the Maltese Islands. Triton, 23: 10-18.

This paper is an addendum to the four volumes on marine mollusc records from the Maltese Islands by Cachia, Mifsud & Sammut (1991; 1996; 2001; 2004 - see full references below). In this paper, 99 additional records are mentioned together with a number of corrections of previous records.

Of particular interest is a second species of Paludinella for Malta. This minute snail is rare and lives in marshes, and previously only Paludinella littorina (Delle Chiaje, 1828) was known to occur. Samples from Salina Bay have yielded some individuals of Paludinella sicana (Brugnone, 1876).

A comparison of Paludinella sicana (Brugnone, 1876) and Paludinella littorina (Delle Chiaje, 1828), pictures taken from the Natuurhistorisch Museum Rotterdam collection

Also worthy of mention is the first Central Mediterranean record of the pyramidellid Leucotina eva Thiele, 1925.

2. Deidun, A., Galea Bonavia, F. & Schembri, P. J., 2011. Distribution of Tylos spp. in the Maltese Islands and population dynamics of Tylos europaeus. Journal of Coastal Research, SI 57: 369-372.

Tylos is a genus of woodlice, two species of which - Tylos europaeus Arcangeli, 1938 and Tylos sardous Arcangeli, 1938 - occur on two sandy beaches on island of Gozo. This paper examines their habitat and gives an account of yearly fluctuations in the former's population.

References:

Cachia, C., Mifsud, C. & Sammut, P., 1991. The Marine Shelled Mollusca of the Maltese Islands Part 1: Archaeogastropoda. Malta: Grima Printing & Publishing Industries; 112 pp.

Cachia, C., Mifsud, C. & Sammut, P., 1996. The Marine Mollusca of the Maltese Islands, Part 2: Neotaenioglossa. Netherlands: Backhuys Publishers; 228 pp.

Cachia, C., Mifsud, C. & Sammut, P., 2001. The Marine Mollusca of the Maltese Islands Part 3: Sub-class Prosobranchia to sub-class Pulmonata, order Basommatophora. Netherlands: Backhuys Publishers; 266 pp.
Cachia, C., Mifsud, C. & Sammut, P., 2004. The Marine Mollusca of the Maltese Islands Part 4: Caudofoveata, Solenogastres, Bivalvia, Scaphopoda and Cephalopoda. Netherlands: Backhuys Publishers; 270 pp.

Endangered Species Day 2011

2011-05-20T16:59:00.000+02:00

On the occasion of Endangered Species Day 2011, I present one of the most characteristic floral endemics of Malta, namely the Maltese Everlasting (Helichrysum melitense). This plant grows on the cliffs of Dwejra (Gozo) and Fungus Rock, and is most probably extinct in the wild from Malta. The remnants of the population are threatened by quarrying (mostly illegal), dumping of construction materials, alien species and habitat deterioration.

Helichrysum melitense (Pignatti), Dwejra - Għawdex, 21.VI.2008

Sealed destiny?

2011-05-17T12:36:00.000+02:00

Monachus monachus (Herrmann, 1779), picture from marinebio.org

The Mediterranean monk seal, Monachus monachus (Herrmann, 1779), sometimes appearing also around Malta (Lanfranco, 1969), is one of the species cited as being 'close to extinction' by the EU environment commissioner Janez Potocnik. About 400 individuals are left around the Mediterranean and many factors heavily influence the decline of the population, including viral diseases, though most threats are anthropogenic.

The Mediterranean Monk Seal on a 2004 stamp from Maltapost

References:

Lanfranco, G. G., 1969. Maltese Mammals (Central Mediterranean). Progress Press: Malta.

MarineBio, undated. Monachus monachus, Mediterranean Monk Seal. [www document, url=http://marinebio.org/species.asp?id=343, last accessed 17.V.2011]

The Roman Villa in Żejtun

2011-05-14T21:31:00.001+02:00

Today's edition of the Times of Malta reports that remains of a Roman Villa in Żejtun will be cleaned up and conserved. The following are some pictures taken in 2009 at this site.

It is interesting to note that, in the course of about two millennia, yellow colonies of the lichen Xanthoria parietina have colonized most of the limestone blocks available, and only rarely are they found growing on the earthenware tiles. This is probably a direct effect of the materials' porosity relative to each other.

A collection of lichens

2011-04-29T13:35:00.003+02:00

Lichens are a group of fungi that have, during the course of evolution, entered a mutual association with algae or cyanobacteria, resulting in a complex relationship that benefits both organisms and allowing them to colonize habitats which would otherwise be inaccessible to the fungus or to the algae by itself.

These habitats may range from bare rock to tree trunks; considerable variety is amply demonstrated even in a relatively small area such as the Buskett woodland, where all the following photographs were taken.

Caloplaca sp., a distinctive yellow lichen which covers bare rock

Ramalina durieui, found mostly on thin branches of pine (Pinus halepensis) and cypress (Cupressus sempervirens)

Another 'leafy', cypress-loving species

This lichen appears to prefer dead bark of the pine tree

A black lichen using rock as its substrate. The green growth consists of moss, which, unlike lichen, is a true plant.

A white lichen on rock.

From the depths

2011-04-25T13:50:00.000+02:00

On the occasion of the World Wildlife Fund's 50th anniversary, the folks at Maltapost have issued a four-stamp set featuring the remarkable Chimaera monstrosa L., 1758.

Chimaera monstrosa L., 1758 on a Maltapost 2011 issue

Known in Maltese as Fenek il-Baħar (lit. sea rabbit), this is a cartilaginous fish, closely related to sharks, commonest at depths of between 500 and 800 metres in the Mediterranean and the East Atlantic. Populations are threatened by the fishing industry and may soon be categorized as 'vulnerable' under IUCN criteria.

Argiope revisited

2011-04-05T09:34:00.002+02:00

After overwintering, the egg sac of the spider featured in this post has opened to reveal the hatched young. Few will make it to adulthood, and some of those which will, namely the males, will be devoured as a post-coital snack by the comparatively huge female.

Juveniles of Argiope lobata Pallas, 1772 - Siġġiewi

The species in question, Argiope lobata Pallas, 1772, is also being investigated as the source of the therapeutically useful toxins it produces to kill its prey.

Molecule of A. lobata's argiotoxin ArgTX-636, from Wikipedia

The photograph of the juvenile spiders comes courtesy of Mr. Patrick Tabone.

Not welcome

2011-02-13T23:20:00.001+01:00

Species spotlight XI

2011-02-11T11:10:00.001+01:00

Mercuria cf. similis (Draparnaud, 1805)
Xlendi, Gozo

The family Hydrobiidae is a large group of small snails with gills (not lungs) living in aquatic habitats, predominantly fresh and brackish. Four representatives are found in the Maltese Islands, the largest of which is the freshwater Mercuria cf. similis (Draparnaud, 1805)*. As a denizen of fresh water bodies, usually close to Blue Clay substrates, Mercuria is rare in Malta but rather more frequent in Gozo. Colonies graze microscopic algae growing on submerged or perennially wet overhangs, and seem to prefer running, clear water. The blue-greyish shell, large shell size and habitat distinguishes it from a similar species, Pseudamnicola moussonii (Calcara, 1841), which will be discussed in a future post.

*In taxonomy, a 'cf.' indicates uncertainty in assigning a specific epithet to a specimen. The uncertainty in this case derives from anatomical differences between Maltese Mercuria and other populations of M. similis.

Mġarr, Gozo

Species spotlight X

2011-02-06T21:05:00.005+01:00

Many members of the family Ferussaciidae tend to adopt subterranean or cavernicolous lifestyles. One such species may be found living in areas of clayey soil along the cliffs and beaches of Mellieħa; this is the small and elusive Hohenwartiana hohenwarti (Rossmässler, 1839), which at first glance resembles its relative Ferussacia folliculum (Gmelin, 1791).

Hohenwartiana hohenwarti (Rossmässler, 1839)
Għajn Tuffieħa, Malta

In contrast to Ferussacia, however, the elongated shell of Hohenwartiana is light and thin enough to render the internal organs clearly visible. The streamlined shape allows the animal to easily navigate around the clay fragments in which it lives. After the death of the animal, the shell turns an opaque white and disintegrates relatively quickly.

The specimen above was retrieved from clay for photographic purposes and replaced quickly. My hand in the background gives an idea of the specimen's size.

It's a snail's life...

2011-02-04T13:25:00.002+01:00

Click on image for a larger view.

Species spotlight IX

2011-02-03T09:21:00.005+01:00

Tudorella melitense (Sowerby, 1847)
Xlendi, Gozo

Tudorella melitense (Sowerby, 1847) is the only snail with an operculum ('door') which is native to the Maltese Islands. Under a 'biological species definition' it may be considered to be a local variety of Tudorella sulcata (Draparnaud, 1805), which also occurs in Sicily; Pfenninger et al. (2010)*, in their work on the DNA of Tudorella, consider it a lineage which is only found in the Maltese Islands.

Għajn Tuffieħa, Malta

The shell is very variable, and may be orange, white or purple, with or without bands.

Għajn Tuffieħa, Malta

*Pfenninger, M., Véla, E., Jesse, R., Arantzazu Elejalde, M., Liberto, F., Magnin, F., Martínez-Ortí, A., 2010. Temporal speciation pattern in the western Mediterranean genus Tudorella P. Fischer, 1885 (Gastropoda, Pomatiidae) supports the Tyrrhenian vicariance hypothesis. Molecular Phylogenetics and Evolution, 54: 427-436.

Species spotlight VIII

2011-01-27T12:03:00.003+01:00

Oxychilus draparnaudi (Beck, 1837)

Buskett, Malta

Today's featured species is a small to medium-sized snail characterized by a brown, glossy and rather flat and fragile shell. It inhabits damp substrates such as compost or leaf litter in gardens or the compact soil beneath stone boulders. The animal is a distinctive blue-grey and is an active predator on other snails.

Oxychilus is a highly speciose genus distributed throughout Europe and the Near East.

Pembroke, Malta

Islands of the Maltese Archipelago - Part II

2011-01-26T15:20:00.002+01:00

Selmunett (St. Paul's Islands)
Off the northeastern coast of Malta

An alien fish in Maltese waters

2011-01-24T16:27:00.007+01:00

A research paper regarding the first recorded occurrence of the Pacific fish Oplegnathus fasciatus (Temminck & Schlegel, 1844) in Malta was recently published in the journal Acta Ichthyologica Et Piscatoria.

Oplegnathus fasciatus (Temminck & Schlegel, 1844)
Valletta, Malta

photo by John Attard

More information may be found here, while the work in its entirety may be accessed here.

Stone spiral

2011-01-23T02:05:00.006+01:00

Cypraea sp.
Chattian, Oligocene

Lower Globigerina Limestone, Birżebbuġa, Malta

Species spotlight VII

2011-01-18T11:22:00.004+01:00

Eobania vermiculata (Müller, 1774)
Żurrieq, Malta

The steppe areas of Malta are frequently populated by large snails from the family Helicidae, amongst which this species, Eobania vermiculata, commonly prevails. The shape and pattern of the shell is highly variable. In Malta, this is not a species utilized for food, unlike in the rest of Europe.

Rabat, Malta

Shell identification:

large thick shell
white base colour
frequently banded
flared lip

From cyberspace

2011-01-15T17:26:00.007+01:00

The unparalleled learning opportunities offered by the medium known as the internet never cease to amaze. Today, I read about the connection between flies and serial killers, watched the awesome vampire squid from hell and other deep-sea oddities, browsed Ernst Haeckel's artistic renditions of the natural world and Heiko Metzner's collection of salticid spiders and Igor Siwanowicz' insect macros, then sat back and virtually dissected a cockroach.

Have a great Saturday evening!

Ernst Haeckel (1898) - Lacertilia

A contribution to 'Sagħtar'

2011-01-13T23:59:00.005+01:00

Sagħtar is a students' magazine in its 37th year of publication. This month's issue includes information on some snails found in the Majjistral Nature & History Park. This article was written by Annalise Falzon from Nature Trust Malta and features a couple of my photographs. (click on image to view in full size)

Species spotlight VI

2011-01-12T22:28:00.006+01:00

Xerocrassa meda (Porro, 1840)
Santa Venera, Malta

One of the commonest snails in Maltese gardens is this medium-sized species that apparently does not mind living in human-influenced habitats, actually preferring cultivated patches to the Mediterranean garigue so beloved of its other relatives. It might have originally been a Maltese and South-Sicilian endemic, eventually spreading to other Mediterranean islands by human intervention.

X. meda is one of two species in the genus Xerocrassa in Malta, which is sometimes treated as a synonym of Trochoidea, but which actually presents anatomical differences from that genus and is herein treated separately following the AnimalBase entry.

Shell identification

6-8mm
pale brown or cream colour with darker bracket-shaped stripes
aperture with a slight pinkish colour
umbilicus pin-point shaped

Species spotlight V

2011-01-11T16:04:00.005+01:00

Deroceras panormitanum (Lessona & Pollonera, 1882)
Żejtun, Malta

This is another slug described by the same folks who named yesterday's featured species. It is a south-west Mediterranean species which has since spread to most of Europe, North America and elsewhere. It can be distinguished from other Maltese slugs by its chestnut-pink colour, smaller size (about 2-3cm) and a fingerprint-like pattern on its back. A very similar species, Deroceras golcheri Regteren Altena, 1962 is endemic to Malta but is much rarer, and in places where it occurs with D. panormitanum, differences in colour and size are constant and consistent. D. golcheri also has a black mark near its pneumostome (respiratory opening, visible in both pictures) which D. panormitanum lacks.

Deroceras also has an internal shell.

Pictures are of the same individual.

Identification

small fast-moving slug
pinkish or pale brown
mucus transparent
fingerprint pattern on back
no black mark near respiratory opening

Species spotlight IV

2011-01-10T09:18:00.011+01:00

Lehmannia melitensis (Lessona & Pollonera, 1882)

Mdina, Malta

Lehmannia melitensis (Lessona & Pollonera, 1882) is a slug and thus appears shell-less, though a thin shell called limacella is present inside the body of the animal. This slug seems to be prevalent in the areas from Ta' Qali up to Rabat and varies from very light grey to almost black. It is similar to another more common slug called Milax nigricans (Philippi, 1836), which, however, has an angled dorsal side.

Lehmannia melitensis (Lessona & Pollonera, 1882)
Buskett, Malta

L. melitensis is distributed throughout Malta, Sicily, Sardinia and other places. Maltese specimens are usually greyer than those from other places. More information on this species and its congener Lehmannia valentiana (Férussac, 1822) may be found here.

Identification

grey or black
dark stripes running along its upper body
fingerprint pattern on back
rounded back

Species spotlight III

2011-01-09T22:01:00.012+01:00

Lampedusa imitatrix (Böttger, 1879)
Mtaħleb, Malta

The clausiliid genus Lampedusa is endemic to Malta and the island of Lampedusa. In Malta it consists of two species, both of which are restricted in occurrence and live solely in highly calcareous habitats. The long and thin shell is characteristic of the family to which these snails belong. The picture shows a group of Lampedusa imitatrix (Boettger, 1879) individuals aestivating in Mtaħleb together with one (distant) relative - Cantareus aspersus (Müller, 1774). The other Maltese congener Lampedusa melitensis (Caruana Gatto, 1892) will be encountered later; while the third and final species Lampedusa lopadusae (Calcara, 1846), endemic to another Mediterranean island, is the subject of this post.

Baħrija, Malta

Shell identification

long and narrow shell
shell top not broken
ribbed
more than two incomplete ribs on last whorl
shell tapers down near opening

The rediscovery of Gibbula nivosa

2011-01-06T23:29:00.010+01:00

The best known marine snail endemism in the Maltese Islands is certainly Gibbula nivosa Adams, 1851 - in vernacular, this is the Maltese Topshell. This mollusc was previously known in a 'live setting' only from St. Thomas' Bay in Marsaskala, with the ever-increasing scarcity of live individuals leading some authors to speculate on its extinction.

A paper published last November, however, sets the record straight - G. nivosa is alive and kicking (albeit in a critically endangered manner) in two localities around the Maltese Islands. You can read the original abstract here and a synopsis here.

Gibbula nivosa Adams, 1851
on a 1979 stamp

Lungo il Tevere

2011-01-05T23:11:00.000+01:00

the river Tiber, by night

A walk around the Colosseum

2011-01-04T12:41:00.011+01:00

The Amphitheatrum Flavium, better known as the Colosseum, is an iconic Roman era building in the centre of Rome. Ravaged by natural phenomena and looters throughout the centuries, it still stands towering above the city, and offers a wonderful opportunity to admire the architectural and engineering prowess of the ancient Romans.

In 1643, far before the advent of Linnaean taxonomy, a gent by the name of Domenico Panaroli decided to publish an inventory of the plants found inside the Colosseum after noticing several exotic (mainly North African) species inside and around it, resulting in the tome Plantarum Amphytheatralium Catalogus. Nowadays, the list of species from the Colosseum has grown to 684 species of plants (Caneva, 2003).

A humidity-loving moss, bearing sporangia (fruiting bodies) on stalks

Adiantum capillusveneris L., also found in Malta

Cymbalaria muralis G. Gaertn., B. Mey. & Scherb.

Of course, the ample vegetation offers much cover for my favourite invertebrates - snails. The most common ones present in soil were Eobania vermiculata (Müller, 1774) and a species of Cernuella (I have not yet decided which this is out of the confusing trio of C. virgata (Da Costa, 1778), C. cisalpina (Rossmässler, 1837) and C. neglecta (Draparnaud, 1805)). Later on, a few specimens of Papillifera bidens (Linnaeus, 1758) and Xerotricha apicina (Lamarck, 1822) were encountered amongst the ruins.

Cernuella sp.

Xerotricha apicina (Lamarck, 1822)

On a totally unrelated note, here's one of the modern day inhabitants of the Colosseum:

References:

Caneva, G., 2003. The Colosseum's use and state of abandonment as analysed through its flora. International Biodeterioration & Biodegradation, 51: 211-219.
Panaroli, D., 1643. Jatrologismi sive medicae observationes quibus additus est in fine Plantarum Amphytheatralium Catalogus. Typis Dominici Marciani, Rome.

Memento mori

2011-01-03T00:05:00.007+01:00

taken in Rome, 2011

When in Rome...

2011-01-02T22:52:00.008+01:00

One thing that surprised me during a short stay in Rome is the sheer quantity of birds, nonchalantly living side by side with the people leading their hectic lives. While in Malta large birds tend to stay far away from any human settlements (and with good reason), Rome features interesting avifauna in addition to the 'usual' sparrows (Passer spp.) and rock pigeons (Columba livia Gmelin, 1789).

Pigeons (Columba livia) in Piazza Santa Maria Maggiore

The largest amongst these birds is the yellow-legged gull (Larus michahellis michahellis Naumann, 1840). Several of these can be seen flying, seemingly fearlessly, over piazzas and public places, descending to gobble anything edible in sight. This particular specimen below was unperturbed by my steady approach towards it, only flying away once it had had its fill of the fresh fountain water.

Larus michahellis michahellis bathing in front of the Santa Maria Maggiore Basilica

The same bird, taking risks

Also notable is the less common hooded crow (Corvus cornix cornix Linnaeus, 1758), of which a couple were observed rummaging around for food beneath cars in one of the very busy roads. The calls of these crows are quite peculiar and could be heard intermittently from trees and stonework, even though their owners were not so commonly seen.

Corvus cornix cornix Linnaeus, 1758

Species spotlight II

2010-12-27T13:35:00.007+01:00

Truncatellina callicratis (Scacchi, 1833)
Lunzjata, Malta

Truncatellina callicratis (Scacchi, 1833) is the smallest landsnail in Malta and the only recent representative of its family, the Vertiginidae. Never exceeding 2mm in length, it is found in large (though localized) populations in leaf litter of trees such as Ceratonia siliqua (Carob Tree/ Ħarruba), such as the one below in Lunzjata, Rabat:

The species is probably under-recorded due to its small size and habitat restrictions.

Shell identification

about 2mm
about as twice long as it is wide
compact cylindrical shape

Species spotlight I

2010-12-24T10:57:00.009+01:00

Ferussacia folliculum (Gmelin, 1791)
Munxar, Għawdex

Ferussacia folliculum (Gmelin, 1791) is a common tiny snail which lives in a variety of habitats, as long as sufficient cover from the sun's heat is present. It is usually found in moderate to large-sized populations, such as the one composed completely of juvenile individuals, as shown below (photo taken in Pembroke, Malta):

The shell is brown and quite glossy. The yellowish colour visible in the above picture is imparted by the snail's foot, as is shown better thanks to the 'one that got away':

Shell identification

glossy brown shell
transparent when fresh
large last whorl
tall and pointed
relatively thick shell
tooth at the base of aperture

Scales in stone

2010-12-20T17:09:00.003+01:00

From the 12th of this December to the 16th of January 2011, Heritage Malta is organizing an exhibition on fossil fish from the Maltese Islands at the National Museum of Natural History (NMNH) in Mdina.

Such remains are of high importance, both palaeontologically and historically, being featured in several scientific publications including palaeoecological studies and new taxonomic descriptions. Most are also extremely rare, with fragile bones that do not fossilize easily.

To whet appetites, here's a taster of what the NMNH collection of fossil fish includes:

Stereodon melitensis Owen, 1864

Myliobates sp.

Holocentrum melitense Woodward, 1887

Best wishes for 2011

2010-12-20T16:40:00.000+01:00

Islands of the Maltese Archipelago - Part I

2010-12-17T10:00:00.001+01:00

Filfla

Southermost island of the Maltese Archipelago

General's Rock

Westernmost island of the Maltese Archipelago

Entomological Society of Malta - vol. 3 launch

2010-12-15T22:24:00.010+01:00

The launch of the annual third volume of papers in the excellent series by the Entomological Society of Malta took place this evening at the sumptuous Casino Maltese in Valletta. The occasion consisted of short talks and a presentation on what is included in this journal, entitled Bullettin of the Entomological Society of Malta.

The contents of this issue are:
1) A first Maltese record of a non-pollinating wasp of Ficus sp.
2) A review of the tineid moths from Malta including the description of a new species - Euthria melitensis Gaedike & Zerafa, 2010
3) A review of the Maltese Heteroptera with seven new records
4) A survey of potentially disease-carrying mosquito species in Malta
5) A review of the weevils of the Maltese Islands with 51 new records
6) A section aimed at young entomologists

Another moth was described in the second issue of the journal from 2009; this was Stichobasis postmeridianus, shown below. Both are, as far as is known, endemic species.

Stichobasis postmeridianus Zerafa & Sammut, 2009

For information on how to obtain Volume 3 or any of the previous ones please contact:

Entomological Society of Malta
P. O. Box 9
Marsa MRS1000
Malta

Waiter, there's a snail in my paella

2010-11-05T01:24:00.012+01:00

While spending a few days in València, Spain, I was surprised at the general lack of snails and slugs even in the grassiest of places along the riverbanks. A cursory search in the huge public park resulted in the finding of just three Cochlicella barbara (L., 1758) specimens on a nightly 'romp', but then, the well-maintained and intensely cultivated area was perhaps not the optimum environment for worthwhile molluscan discoveries.

Part of Valencia from above

The Valencians have many exquisite traditional dishes, frequently making ample use of seafood and landsnails. In a particular market, I was surprised to see that three species of the latter are farmed and packaged separately for consumption. These are Theba pisana (Müller, 1774), Otala punctata (Müller, 1774) and Cantareus aspersus (Müller, 1774) (pictured beneath in respective order). All three species are also present in Malta, yet here only the latter is consumed.

I later found a sub-adult Otala punctata in my Valencian paella take-away.

Happy Halloween!

2010-10-29T13:15:00.003+02:00

Felis catus (L., 1758) var. maleficus

A rare tree snail

2010-10-20T18:16:00.006+02:00

From Sumatra, Indonesia - this is original footage one of the rarest tree snails known, Amphidromus (Goniodromus) bulowi Fruhstorfer, 1905 - only rediscovered a century after its original description in 1905 and unfortunately well on its way to extinction.

Video uploaded thanks to Mr. John Abbas.

New paper published

2010-10-15T12:45:00.006+02:00

Pseudotachea splendida (Draparnaud, 1801) - Qormi, Malta.

A paper of interest to the readers of this blog has just been published in this month's issue of the journal Triton.

Cilia, D. P., 2010. A note on shells of Pseudotachea splendida (Draparnaud, 1801) in the Maltese Islands (Central Mediterranean). Triton, 22: 33-34.

Abstract: Shells of the western European helicid Pseudotachea splendida (Draparnaud, 1801) are recorded from a plant nursery in Malta.

The private life of snails

2010-10-09T01:36:00.004+02:00

This event is happening at the Majjistral Nature and History Park on the 21st of November. Please click on the picture for a better view!

Tourism & Biodiversity

2010-09-27T15:44:00.014+02:00

The 27th of September is World Tourism Day. The Malta Tourism Authority is celebrating this year's theme - "Tourism & Biodiversity" - by issuing a set of four stickers which feature typical organisms of the Maltese Islands.

Understandably, the variety of flora and fauna pictured is diverse and includes a plant, two invertebrates, and two vertebrates. These are, respectively:

Capparis orientalis Veillard (noted on the sticker under the synonym Capparis spinosa L.);
Papilio machaon melitensis Eller, 1936 (an endemic butterfly);
Echinaster sepositus sepositus (Retzius, 1783);
Epinephelus marginatus (Lowe, 1834) (noted on the sticker under the synonym Epinephelus guaza L., 1758);
and the Maltese national bird Monticola solitarius L., 1758.

Please click on image for larger version!

Sex! Murder! Cannibalism!

2010-09-22T22:47:00.010+02:00

It looks like the blurb for some low-budget 70's horror flick, but such storylines are relatively commonplace in the arthropod world. Argiope lobata Pallas, 1772 is a spider displaying extreme sexual dimorphism - the small male is seldom seen, but the female is one of the largest arachnids found in the Maltese Islands.

As in some other arthropods of the sexually dimorphic ilk (e.g. praying mantises and crabs), the hapless male is frequently cannibalized by the female (seen in the pictures above) following mating. It is mainly seen in humid and shaded habitats suspended head downwards from its very strong web, patiently waiting for prey.

A hardy egg sac like the one below is subsequently constructed nearing the end of the summery season. Hundreds of small spiders hatch and spend the winter inside this sac, emerging in spring.

The images in this post come courtesy of Mr. David Dandria and Mr. Patrick Tabone.

New section

2010-09-18T16:22:00.004+02:00

The picture on the right hand column of this blog labelled 'On S. E. Asian gastropods' now leads to a new page, where I will be posting my work on snails from the region of South-East Asia.

Updates will also be listed accordingly on this main blog section.

Amphidromus sekincauensis Dharma, 2007 - South Sumatra

Tideline barnacles

2010-09-01T00:27:00.003+02:00

Virtually all rocky seashores in Malta sport millions of these unassuming, pyramidal entities that close or open to feed or reproduce depending on the availability of seawater from tide or waves. They are barnacles mostly belonging to the species Chthamalus stellatus Poli, 1791, though other species of Chthamalus are also present on Maltese shores.

As seen in the photograph above (lower right hand corner and upper centre), dead individuals leave behind calcareous volcano-shaped cavities which may be used as a refuge by other intertidal organisms, such as the amphibious and very interesting snail Melarhaphe neritoides (L., 1758) or even other crustaceans such as amphipods. The photograph was taken at Dwejra, Gozo, during receding tide. On the other hand, the photograph below shows completely dry specimens from Buġibba, waiting for the presence of water to resume any activity.

Scorpion, interrupted

2010-08-27T01:26:00.005+02:00

I (unintentionally) interrupted this scorpion at Għajn Tuffieħa while it was feasting upon the remains of a fellow arthropod - a hapless woodlouse, which can be seen still attached to the scorpion's jaws in the lower picture. A few seconds after being discovered, the scorpion released the morsel and assumed a compact, defensive stance, remaining utterly immobile until yours truly decided to leave it in peace and restore its stony hideout to its original place.

Only this species of scorpion exists in Malta. It is the small Euscorpius sicanus (Koch, 1837), also found on other Mediterranean islands.

Brocktorff's Maltese fossils

2010-08-18T15:31:00.004+02:00

Sir William Reid, Governor of Malta from 1851 to 1858, was a military official and amateur scientist whose interests eventually led him towards a study of meteorology and hurricanes. In a bid to encourage interest in the geology of the Maltese Islands, he published a book containing a few lithographs of fossils commissioned from an artist known only as 'Brocktorff' (Zammit Maempel, 2007).

This book remains very rare in libraries. In addition the well-known echinoids, Brocktorff illustrates remains of crustaceans (a crab), cartilaginous fish (the famous glossopetrae), and bony fish. The following are a some of the illustrated specimens, a few of which are in the National Museum of Natural History, Mdina.

'Schizaster Parkinsoni, Defrance' [*]

'Schizaster Desori, Wright' [**]

'Found at Casal -Luca-Krendi in the Year 1854' [***]

'Found near Casal Luca in the Year 1855'

'Shark's Tooth, with Stony Zoantharia - found near St. Thomas Tower, Malta' [****]

[*] Schizaster parkinsoni (Defrance, 1835)
[**] Schizaster desori Wright, 1855
[***] in contemporary Maltese: Casal Luca = Ħal-Luqa; Krendi = Qrendi
[****] St. Thomas' Tower, Marsaskala

References:

Reid, W., 1857. Maltese fossils lithographed for distribution with the view to encourage further investigation into the geology of the island. Malta: Valletta.
Zammit Maempel, G., 2007. Illustrators and their illustrations of Maltese fossils and Geology. Malta: Publishers' Enterprises Group Ltd.

Dissertation - A student’s guide to the geology of the Maltese Islands

2010-08-12T11:59:00.009+02:00

The citation and abstract to my B. Ed. (Hons) dissertation have been added to the links on the right-hand side of this blog. The page can also be accessed through here.

A tenacious fern

2010-08-10T13:58:00.005+02:00

Deep inside caves, plant life is either extremely scarce or otherwise totally absent, which is due to the fact that plants need sunlight in order to manufacture food and therefore survive. However, the occasional thin ray of light may sometimes manage its way through, and this is an opportunity upon which mosses and ferns capitalize without fail.

The picture above shows the common maidenhair fern (Adiantum capillusveneris L.) taking advantage of such an instance at Għar Ħassan. The scant sunlight and nutrient-poor limestone soil are enough for the small but hardy plant.

Adiantum is a feature of many 'traditional' Maltese gardens due to its preference for shaded areas. The vernacular name in Maltese is Tursin il-Bir (lit. water-well parsley). Of course, true parsley is a flowering plant, and has nothing to do with the species in question.

Sharks in Malta Part III - Close encounters of the third kind

2010-08-09T17:36:00.006+02:00

Today I was surprised that virtually all of the Google searches leading to this blog consisted of the same three keywords: 'shark in Malta'. I attributed this sudden interest to some sensational news item about which I hadn't heard anything so far - and sure enough, one glance at the Times of Malta web portal explained everything.

Without further ado, here's the link to the relevant news item and the accompanying video. Non-Maltese speakers will be disappointed, though!

The Maltese flint

2010-08-06T15:51:00.005+02:00

The silicate mineral quartz is, in addition to calcite, one of the commonest minerals on the earth’s crust. An amorphous (non-crystalline) form of this mineral, called variously chert (highly impure) or silex or flint (relatively pure), is found in certain strata of the Maltese rocks.

In a pure state, silicon dioxide is of a transparent colour. This can be seen in crystalline specimens of quartz found in volcanic rocks which are termed ‘rock crystals’. In Malta, nodules or blocks of this mineral contain many impurities mainly consisting of calcium carbonate and other salts; this depends on the parent rock in which they form and results in different colours and varying degrees of translucence.

In the Upper Coralline Limestone Formation, nodules of chert are highly calcareous, opaque and microcrystalline in nature. The impurities in these nodules impart a layered dark brown or charcoal colour. Such nodules are common at the Upper Coralline Limestone of Xemxija and Mistra.

Middle Globigerina Limestone outcrops in Baħrija and Mtaħleb contain usually large blocks of light greyish or khaki chert that intergrades with the limestone and fractures very easily (picture above). Very thin sections of this material allow light to pass through. The parts remaining embedded in the bedrock protrude out and are visible as slightly darker patches against the white limestone.

Middle and Lower Globigerina outcrops in north-central Malta (Mrieħel to Msida) also contain chert, albeit in a the very different form of small to medium-sized nodules. These are somewhat darker in colour, and correspondingly, the silicate material found here is of a light brown to reddish colour.

Odds and ends

2010-08-05T01:35:00.006+02:00

Not much time on the laptop on my part has meant a lack of recent blog updates, and for this I do apologize profusely. In the meantime, I have been working on a couple of research papers, two of which which have been submitted and accepted, and some others which are still a long way from being final.

Meanwhile the summery world outside is buzzing with activity, as can be exemplified by the beautiful Xylocopa violacea (L., 1758) below.

This bee is also known as the carpenter bee due to the fact that its eggs are laid inside purposely-bored wood or stems. During my observations I have noticed that the Arundo donax reed is a favoured home for this species.

While the invertebrate world is teeming with insects, however, molluscan representatives are few and far in between, owing to the terrible heat of the Mediterranean summer. The non-marine gastropods that never need worry about this are, of course, those who call freshwater their home, like this Physella acuta (Draparnaud, 1805) from Chadwick Lakes:

Many natural freshwater bodies boast sizable populations of this snail. Other species are much rarer, such as these minute (3mm) Mercuria cf. similis (Draparnaud, 1805) from a Gozitan population:

Burst of purple...

2010-07-09T12:47:00.004+02:00

... or indigo, lilac, anyway - whatever you want to call it. Cheirolophus crassifolius (Bertoloni) is much better known as Widnet il-Baħar, and it has been designated as the national plant of Malta. It is an endemic species with a troubled taxonomic history and embellishes cliffs with its beautiful blooms during most of summer. A very hardy plant which withstands highly alkaline soil, it has also been used as an ornamental and is frequently seen in roundabouts, public gardens and roads, though it remains very rare in the wild.

To read about the Maltese national tree please click here.

A pirate's cave

2010-07-07T16:33:00.007+02:00

The 12th century legend goes that a Turkish pirate by the name of Ħassan, madly in love with a beautiful Maltese girl, abducted her and took her to live with him in a cave in the southern cliffs of Malta. The villagers soon realized this and were immediately off to rescue the girl, then give the Turk the punishment he deserved. Upon hearing their shouts, the defiant Ħassan pushed the girl down the cliffs to her death, and leapt after her before anyone could catch him.

The locality where this tragic tale is supposed to have taken place is, fittingly, called Għar Ħassan (Ħassan's Cave). It lies between Bengħisa and Ħal-Far, punctuating the Lower Coralline Limestone cliffs making up most of the area. Like many other caves in the Maltese Islands it is a phreatic tube formed by the dissolution of limestone in water, and this is very evident in the smooth appearance of the cave walls.

Għar Ħassan consists of a central large chamber, the accessible part of which measures about 60m. Two main paths intersect with the main one at about 20m into the cave; the one to the east (above) leads to another opening in the cliff-face while the one to the right narrows down, eventually becoming inaccessible. Some parts of the main tube are perennially wet and mainly soft calcite deposits can be seen in several places on the walls of the cave. Clayey soil, consisting of the insoluble components of limestone, covers the entire floor of the cave and is sometimes cemented in place by calcite from hard water dripping from the ceiling. Soil has prevented stalagmites from forming over the limestone floor.

A fault running along the main chamber, quite visible on the roof of the cave (above), probably contributed to to the formation of the cave by fracturing and therefore making the usually firm Lower Coralline Limestone far less resistant to water flow.

Nightlife in Fgura

2010-06-29T02:45:00.006+02:00

Walking through Fgura at 01:30AM, my girlfriend and I noticed a black shadow scurrying along the edge of the road. Too fast for a kitten and too large for a mouse, we soon realized it was a rat.

Of course I tried to stalk it quietly in the hope of obtaining a couple of good photographs, but apparently not quietly enough to prevent it from disappearing almost immediately, leaving me with just this:

I am inclined to think it's the common black rat Rattus rattus, though identification is not easy if only external morphology is taken into account.

Gozo crocodiles

2010-06-23T01:47:00.006+02:00

The picture above shows a fossil skull of the Miocene crocodilian Tomistoma gaudensis (Hulke, 1871) from the Globigerina Limestone of Gozo. This specimen is located at the National Museum of Natural History, Mdina, reg. no. NMNH-T11228. Another species, namely Tomistoma champsoides (Owen in Hulke, 1871) is also known to have occurred in the area now occupied by the Maltese Islands.

Reference:

Hulke, J. W., 1871. Note on some reptilian fossils from Gozo. Quarterly Journal of the Geological Society, 27 (1-2): 29-33.

Another garden visitor

2010-06-20T15:00:00.006+02:00

It's another butterfly - smaller and much less conspicuous than its relative which I wrote about this week - yet just as beautiful and interesting. According to Sammut's definitive book on the Maltese butterflies and moths, this is Syntarucus pirithous (L., 1767), which is frequently encountered throughout the warm season.

Reference:

Sammut, P., 2000. Il-Lepidoptera. Kullana Kulturali, 12: 1-246. Malta: Pubblikazzjonijiet Indipendenza.

Lampedusa... from Lampedusa

2010-06-18T13:08:00.004+02:00

The snail genus Lampedusa consists of three species, two of which are endemic to Malta and quite localized in occurrence. The other is Lampedusa lopadusae (Calcara, 1846), which is endemic to the island of - wait for it - Lampedusa. Unlike the Maltese species, this occurs quite commonly on the island and, amongst others, colonizes habitats which its Maltese counterparts don't: bark of trees, grass and so on. The Maltese species seem to prefer limestone patches.

Photograph of a typical aggregation of the snails taken in 2005 by Arie W. Janssen.

Beach blooms

2010-06-16T11:35:00.006+02:00

One of the most large and noticeable summer flowers occurring in Malta is the sea daffodil (Pancratium maritimum L.), which requires a sandy habitat and is therefore quite rare. It usually blooms in mid-summer, however, the Għajn Tuffieħa population is already in full bloom. I took the following photos in the area yesterday.

Another population of the plant occurs on the sand dunes at Ramla l-Ħamra, Gozo (photographed 26.I.2009).

A lepidopteran pit stop

2010-06-14T07:58:00.005+02:00

A frequent migrant in June is the elegantly-named butterfly Vanessa (Cynthia) cardui (L., 1758), passing over Malta from North Africa on the way to cooler European climates. The following pictures, taken yesterday in Santa Venera, show a very small sample of hundreds of individuals feeding on the nectar of cultivated plants, before continuing their journey. They seem to prefer the Lantana shrubs above anything else, though this may be because of the flowers' bright yellow colour - purple-flowered Lantana shrubs were hardly visited.

A Mediterranean inspiration

2010-06-09T18:32:00.007+02:00

The plant shown above, Acanthus mollis L., is widely held by historians to be the inspiration behind a highly characteristic element of ancient Greek (Corinthian) and Roman architecture - the so-called 'Acanthus motif'. This feature is expressed mostly in column capitals, as shown below*.

For the Romans, the Acanthus plant held connotations of resurrection, as evidenced by the following quote from the architect Vitruvius:

The invention of the capital of this order is said to be founded on the following occurrence. A Corinthian virgin, of marriageable age, fell a victim to a violent disorder. After her interment, her nurse, collecting in a basket those articles to which she had shown a partiality when alive, carried them to her tomb, and placed a tile on the basket for the longer preservation of its contents. The basket was accidentally placed on the root of an acanthus plant, which, pressed by the weight, shot forth, towards spring, its stems and large foliage, and in the course of its growth reached the angles of the tile, and thus formed volutes at the extremities. - Marcus Vitruvius Pollio, 'De Architectura IV', 25 B. C.

Acanthus is a genus mostly native to the Mediterranean region, though it has been grown in many gardens around the world for its beautiful foliage and flowers. Its name in Maltese is Ħannewija.

*image by Jane Vadnal, University of Pittsburgh. Pictures of plant (1): Fiddien 27.V.2009; (2-3): Buskett 06.V.2009

A cliffhanger

2010-06-08T18:42:00.005+02:00

The buds of the plant shown flowering above, Capparis orientalis Veillard, are traditionally pickled in brine and used on bread, in salads and in sauces all around the Mediterranean.

Capparis in Malta usually grows on cliffsides and other natural vertical rock faces. However, it is also found growing profusely on old bastion walls, which mimic some of the ecological conditions found on cliffsides.

Of a painter and a doctor

2010-06-07T16:22:00.012+02:00

Yesterday was the closing day of an exhibition of paintings by Edward Caruana Dingli (1876-1950), an idealist Maltese artist well known for memorable folkloristic watercolours, as well as iconic portraits of several dignitaries of the time.

Amongst these portraits, one depicting the scientist, doctor and archaeologist Themistocles Zammit (1864-1935) was spotted. In 1905, Zammit discovered that the bacterium Brucella melitensis (Hughes, 1893) was transmitted through goat milk, earning him knighthood and enabling food handlers of the time to drastically limit the infectious pathways of the organism. Brucella melitensis causes undulant fever and was first noticed and studied in Malta, hence its specific name.

Sir Themistocles Zammit - portrait by Edward Caruana Dingli (1926)

Zammit's discovery was extremely important, considering that at the time farmers sold their fresh goats' milk on a door-to-door basis, and pasteurization on an industrial scale was still a long way off. The goat milk vendor has nowadays disappeared from Malta, but he has been immortalized in a number of paintings, amongst which is 'The Milk Vendor', also by Caruana Dingli.

'The Milk Vendor' - Edward Caruana Dingli (undated)

Goat numbers have also declined with the demand for their produce. Goats are indiscriminate eaters and may damage natural ecosystems irreversibly, as can be seen in garigue areas like Magħlaq, where the large majority of plants present are Scilla and Asphodelus, which goats avoid. Unfortunately, some herds still remain grazing at places of high ecological sensitivity, such as Munxar (Gozo), where an extremely rare form of the snail Muticaria macrostoma (Cantraine, 1835) occurs.

Goats grazing in Munxar, Gozo

References:

Fondazzjoni Patrimonju Malti, 2010. Edward Caruana Dingli: Portraits, Views and Folkloristic Scenes. Malta: Fondazzjoni Patrimonju Malti, 32 pp.

Wyatt, H. V., 2005. How Themistocles Zammit found Malta fever (brucellosis) to be transmitted by the milk of goats. Journal of the Royal Society of Medicine, 98: 451-454.

Sharks in Malta Part II - A killer reputation

2010-06-03T13:57:00.009+02:00

The vast majority of sharks and rays frequenting Maltese waters are innocuous to humans, and even the largest of them is a timid filter-feeder - this is the legally protected basking shark - Cetorhinus maximus (Gunnerus, 1765).

The species after larger prey, such as the great white shark (Carcharodon carcharias Smith, 1838), may attack humans on occasion, and such one-off cases are so easy to sensationalize that the shark is now perceived as dangerous and fear-inspiring. Coupled with overfishing and pollution, this reputation has had grave consequences for shark populations around the world - both species mentioned above are considered as vulnerable by the IUCN.

The following photographs are some archival finds documenting well-publicised shark catches in Malta throughout the years. Hopefully, awareness and education about the true nature of sharks will help keep such actions restricted to a few old pictures.

Alopias vulpinus (Bonnaterre, 1788) - off Gozo, 2000

Isurus oxyrhincus Rafinesque, 1810 - 10km off Ġnejna, 2005

Hexanchus griseus (Bonnaterre, 1778) - off Marsaxlokk (2008?)

Carcharodon carcharias Smith, 1838 - off Filfla, 1987

References:

Fergusson, I., Compagno, L. J. V. & Marks, M., 2005. Carcharodon carcharias. In: IUCN Red List of Threatened Species Version 2010.1. [WWW Document, url - www.iucnredlist.org; last accessed 03.VI.2010]

Fowler, S. L., 2005. Cetorhinus maximus. In: IUCN Red List of Threatened Species Version 2010.1. [WWW Document, url - www.iucnredlist.org; last accessed 03.VI.2010]

Snailing about

2010-06-02T06:22:00.004+02:00

A Cantareus aspersus (Müller, 1774) going about its daily business. Photo taken in Mqabba.

Sharks in Malta Part I - 'L-Ilsna ta' San Pawl'

2010-05-31T22:33:00.021+02:00

The Sicilian Agostino Scilla was one of the first Europeans (together with Nicholas Steno in Denmark) to systematically study fossils and extract information about them empirically, as opposed to his contemporaries' tendency to attribute fossils to supernatural forces or a slew of mythical creatures.

Frontispiece of Agostino Scilla's 'La Vana Speculazione', 1670 - note the variety of fossils on the lower right

Both Scilla and Steno arrived to conclusions that were beginning to shape the science of geology as it is known today, in particular the then-controversial notion that fossils are derived from once-living organisms.

Interestingly, some of the fossils which both chose to illustrate in their works were obtained from Malta. These fossils are the famous glossopetrae (tongue stones), or, more accurately, fossil shark teeth, which during the Medieval, Renaissance and Baroque periods were considered to be a miraculous cure for a variety of ailments (Zammit Maempel, 1975; 1989). Malta was the centre of a lucrative business in these shark teeth and it is not hard to see how specimens could have come in Scilla and Steno's possession.

Carcharocles megalodon (Agassiz, 1843) teeth from the C2 Phosphorite Conglomerate, Malta

Most of these glossopetrae belong to the extinct Carcharocles megalodon (Agassiz, 1843), one of the largest fish ever to exist on Earth. An approximation of its size (in grey and red) compared to the modern (and morphologically similar) great white shark, Carcharodon carcharias (L., 1758) (in green) can be seen below.

The local name for these particular fossils is 'Ilsien San Pawl' (= St. Paul's Tongue) due to the belief that they formed inside the rocks while St. Paul was shipwrecked on Malta in the year 60 A. D. (Acts of the Apostles, 28: 2-7). During this episode, St. Paul shrugged off a snake which attacked him and threw it into an open fire, symbolically ridding the islands of poisonous 'vermin'.

'St. Paul's Shipwreck', by Stefano Erardi, 1683 - note the snake falling out of the main figure's hands into the fire

Carcharocles teeth from the collection of Sir Hans Sloane are also the oldest Maltese fossils in the British Museum (cf. Galea Bonavia, 2003).

References:

Galea Bonavia, C., 2003. Carcharocles megalodon (Agassiz) (Lamnidae: Neoselachae): A historical note. The Central Mediterranean Naturalist, 4 (1): 105.

Scilla, A., 1670. La vana speculazione disingannata dal senso: lettera responsiva circa i corpi marini, che petrificati si trovano in varii luoghi terrestri. Napoli: Colicchia.

Sloane, H., undated. Se la Virtu’ alessifarmaca della Terra, Glossopetre conchiti, Achini ed altre pietre figurate che si cavano dalle Rocche di Malta, sia innata o Miraculosa. Unpublished manuscript, Sloane Collection – British Library MS no. 763.

Zammit Maempel, G., 1975. Fossil sharks' teeth: a medieval safeguard against poisoning. Melita Historica, 6: 391-406.

Zammit Maempel, G., 1989. The Folklore of Maltese fossils. Papers in Mediterranean Social Studies, 1: 1-29.

Spot the reptile

2010-05-30T19:36:00.009+02:00

It was only after this photograph was taken and downloaded to my computer than I realized that a vertebrate could be seen sunbathing on one of the Opuntia stems. Can you spot it?

If not, here it is again, highlighted and enlarged:

The name of this reptile is Tarentola mauritanica L. 1758. The species is generally nocturnal, but that clearly hasn't stopped this individual from enjoying a breath of fresh air!

Variations on a theme, Part IV

2010-05-28T06:02:00.005+02:00

The most common invasive plant in the Maltese countryside is the Cape Sorrel (Oxalis pes-caprae L.). The pictures below, taken at Għajn Tuffieħa, show the usual variety of the flower (1), together with another less frequent form exhibiting extra petals (2) resulting from additional sets of chromosomes in the cells' nucleus (polyploidy).

It is known for its sour taste resulting from a reserve of oxalic acid in the plant tissues, which has also resulted in its Maltese vernacular name of Qarsu (=sour).

(1)

(2)

Rats!

2010-05-27T23:05:00.005+02:00

One of the commonest rodents in Malta, and the islands surrounding it, is the black rat Rattus rattus (L., 1758). It is usually found living together with man in highly artificial habitats all around the world, but has spread to any area where the temperature is warm enough and where food is in plentiful supply. Since this species is an omnivore (eats both vegetable and animal material), it also creates problematic issues when introduced in areas of ecological uniqueness.

In Malta this problem is seen in mostly relation to the unique reptilian fauna - on the islands of Selmunett, predatory actions of Rattus sp. are the main factors involved in the virtual extinction of the lizard Podarcis filfolensis kieselbachi (Fejervary, 1924), while the introduction of rats on General's Rock may result in the same situation with the lizard Podarcis filfolensis generalensis (Gulia, 1914) (cf. Sciberras & Schembri, 2008; Borg & Sultana, 2003).

The following black rat skulls have been found in Holocene deposits in Buskett and Mistra respectively. The other rat found in the Maltese Islands is the brown rat Rattus norvegicus (Berkenhout, 1769) which, despite its common name, can look highly similar to the black rat in form and colouration.

Examination of the skull, however, makes identification easier.

Black rat Rattus rattus (L., 1798) - specimens from Buskett (left) and Mistra (right). Top photo shows dorsal aspect of the skull, while the bottom photo shows the ventral aspect.

The black rat skull (as can be seen above) has a markedly pointed posterior end, whereas the brown rat's is more rounded. This feature is seen marked with a '1' in the drawings below. In addition, the bony ridges above the eyes also display a distinct difference. They are curved in the skull of the black rat while almost straight in the brown rat's. This feature is seen marked with a '2' in the drawings below. Both drawings are taken from the very interesting paper by Yiğit et al. (1998).

Black rat Rattus rattus (L. 1758) skull drawing

Brown rat Rattus norvegicus (Berkenhout, 1769) skull drawing

References:

Borg, J. J. & Sultana, J., 2003. The presence of the black rat Rattus rattus on Fungus Rock (Maltese islands). The Central Mediterranean Naturalist, 4 (1): 105-106.

Sciberras, A. & Schembri, P. J., 2008. Conservation status of St Paul's Island Wall Lizard (Podarcis filfolensis kieselbachi). Herpetological Bullettin, 105: 28-34.

Yiğit, N., Çolak, E., Sözen, M. & Özkurt, Ş., 1998. The taxonomy and karyology of Rattus norvegicus (Berkenhout, 1769) and Rattus rattus (Linnaeus, 1758) (Rodentia: Muridae) in Turkey. Turkish Journal of Zoology, 22: 203-212.

The 'Scutella Bed'

2010-05-24T23:29:00.002+02:00

Specimen of Scutella subrotunda (Leske, 1778) from the British Natural History Museum, E16593

Leske's original description of the sea-urchin Scutella subrotunda, 1778

The rocks of the Maltese Islands formed beneath the sea in the period spanning from the late Oligocene to the late Miocene, from 28 to 5 million years ago.

By looking at the rocks and the fossils they contain, it is possible to deduce which kind of environment existed all those years ago, by comparing them to present marine habitats and environments.

The Lower Coralline Limestone (known in Maltese as Żonqor) is the first exposed rock of the islands. It was the first to form, 28 to 23 millions of years ago, in the Oligocene period.

Towards the end of the Oligocene, the consistency of the Lower Coralline Limestone changed considerably, passing from frequently semi-crystalline, very compact rock (Attard member) to about ten metres' thickness of relatively less rigid, coarser rock (Il-Mara member), with cross-bedding characteristics. This probably represents very suddenly shallowing water, and may suggest tectonic activity.

This changed environment meant that the seabed was now subjected to stronger currents than before, therefore waves would drag large amounts of debris from deeper waters and deposit them onto these shallow reef-like platforms nowadays called the Maltese Islands.

This debris consisted mostly of organisms and their skeletons, the most common of which was the now extinct sea-urchin Scutella subrotunda (Leske, 1778). The large calcium carbonate testas (usually fragmented, but not exclusively) of huge populations of this echinoid compose one or more layers (up to five) marking the end of the Lower Coralline Limestone phase, to the extent that they have been named 'Scutella Beds' by the British geologist T. A. B. Spratt.

Scutella Bed in Xlendi member Lower Coralline Limestone, Spinola Bay

Scutella fossil in Xlendi member Lower Coralline Limestone, Dwejra (Gozo)

References:

Leske, N. G., 1778. Additamenta ad Jacobi Theodori Klein naturalem dispositionem Echinodermatum et lucubratiunculam de aculeis echinorum marinorum. Lipsiae, Leipzig, 278 pp.
Smith, A. B. (ed.), 2005. The Echinoid Directory. [WWW document, link: http://www.nhm.ac.uk/research-curation/projects/echinoid-directory/index; last accessed: 24.V.2010]
Spratt, T. A. B., 1843. On the geology of the Maltese Islands. Proceedings of the Geological Society of London, 4 (2): 225-231.
Spratt, T. A. B., 1854. On the geology of Malta and Gozo [2nd edition]. Malta, 16 pp.

Some views of Ramla l-Ħamra, N Gozo

2010-05-20T12:28:00.002+02:00

Two parasitic plants

2010-05-10T22:18:00.010+02:00

Parasitic flowering plants are few and far in between. However, two particular genera have been very successful in Mediterranean climates, and both are also represented in the Maltese islands.

The first of these is Cuscuta, which attacks the stems and leaves of other plants - having no roots of its own, this plant entwines itself around other species and sucks nourishment out of their vascular tissues. Its appearance is that of reddish threads interrupted by dense groups of very small white flowers. There are three species of Cuscuta in Malta.

Cuscuta epithymum L. - Magħlaq, 2008. Host - Scilla sp.

The other relevant genus is Orobanche. In contrast to Cuscuta, these parasites attack the roots of other plants. In Malta, one of the commonest species is Orobanche crenata Forsskål, which is very well-known to farmers since it generally attacks legumes (such as broad beans, as in the picture below) and diminishes crop yield.

Orobanche crenata Forsskål - Żejtun, 2009. Host - Vicia faba L.

It may also adapt to parasitism on other plants like Nasturtium, as can be seen in the following picture, taken in St. George's Square at Valletta.

Orobanche crenata Forsskål - Valletta, 2010. Host - Tropaeolum sp.

I would like to thank Dr. S. Lanfranco for confirming the identity of the second Orobanche specimen.

On some fossil brachiopods from the Maltese Islands

2010-05-09T17:58:00.009+02:00

Brachiopods are filter-feeders usually indicating seabeds densely populated with algae. The calcium carbonate shell of these animals is fragile and therefore sufficient shelter from waves is usually needed. In fact, they are mostly found in the Upper and Lower Coralline limestones.

The Il-Mâra Lower Coralline Limestone in the north-east areas of Malta occasionally contains populations of a dwarf form of Terebratula vitrea (von Born, 1778). These fragile brachiopods are usually found in association with cidaroid sea-urchin fragments and large species of foraminifers, including Heterostegina.

Terebratula vitrea (von Born, 1778)

In the westernmost parts of Malta, conspicuous 10 to 20cm thick layers of brachiopod shells are often present in cliff faces composed of the Mtarfa Upper Coralline Limestone, amongst rhodoliths and bryozoan fragments. These fossils are often crushed and identification is difficult unless the shell is broken open. Material from these brachiopod layers was used by Cooper (1983) to describe a new genus and species both named for the type locality, namely Maltaia maltensis Cooper, 1983, considered by other writers (Gaetani & Saccà, 1983) to be a synonym of Terebratula sinuosa (Brocchi, 1814). The latter is also found in considerable numbers in the same strata. However, the former species is markedly different in form and is also found in areas where ‘normal’ T. sinuosa is absent .

Terebratula sinuosa (Brocchi, 1814) (lower picture - detail)

Maltaia maltensis (Cooper, 1983) (detail)

The small (6mm) Megathiris detruncata (Gmelin, 1790) and other small species like Argyrotheca sp. are also very common throughout some parts of the Upper Coralline Limestone Formation.

Megathiris detruncata (Gmelin, 1790)

Deep sea such as that in which the Globigerina Limestone formed also offers protection from strong currents that may damage brachiopods. Despite this, brachiopods in this layer are few and far in between. Disarticulated phosphatised valves of the still-extant Megerlia truncata (Linné, 1767) are infrequently found in the C2 Phosphorite Conglomerate Bed.

Megerlia truncata (Linné, 1767)

References:

Cooper, G. A., 1983. The Terebratulacea (Brachiopoda), Triassic to Recent: a study of the brachidia (loops). Smithsonian Contributions to Paleobiology, 50: 1-445.
Emig, C. C., 2006. Brachiopoda world database. [www document, url: http://www.marinespecies.org/brachiopoda, last accessed: 10.II.2010]
Gaetani, M. & Saccà, D., 1983. Brachiopodi neogenici e pleistocenici della provincia di Messina e della Calabria meridionale. Geologica Romana, 22: 1-42.

Yet another cold-blooded encounter

2010-05-01T19:08:00.009+02:00

The elegant and perfectly camouflaged Telescopus fallax (Fleischmann, 1831) basks in the late afternoon sun on garigue close to Baħrija, Malta.

Apart from the characteristic patches on its skin, the easiest way to distinguish this species is from its slit-like pupils, similar to those of cats, earning it the common English name of 'cat snake'. All other snake species of the Maltese islands have round pupils.

Some views from Għar Lapsi, S Malta

2010-04-30T14:26:00.003+02:00

Some views of Wied Żnuber, SE Malta

2010-04-27T17:40:00.003+02:00

The Maltese national tree

2010-04-22T02:21:00.009+02:00

Tetraclinis articulata (Vahl, 1791) is a North African conifer from the Cypress family. It is also the national tree of Malta, and is known locally as 'is-siġra tal-għargħar'. Most specimens encountered in the wild grow on clay slopes and appear to thrive in quite arid habitats. The picture above shows a mature specimen from the Maqluba depression at Qrendi, while below a young individual from Għajn Tuffieħa bay can be seen.

Sinister sphinxes?

2010-04-19T18:58:00.012+02:00

Hyles (Rommeliana) sammuti Eitschberger, Danner & Surholt, 1998 -

Buskett 11.XI.2009

This is the larva (caterpillar) of an endemic moth from one of the most aesthetically pleasing families in the Lepidoptera, namely the Sphingidae. Before its description in 1998, Maltese specimens belonging to Hyles sammuti Eitschberger, Danner & Surholt, 1998 were thought to belong to Hyles euphorbiae (L., 1758), a common Mediterranean species, due to similar morphology and habitat.

An adult specimen of H. sammuti may be seen below, this photograph is taken from the excellent Sphingidae of the Western Palearctic website.

The sphingids found on the Maltese islands also count amongst their ranks the infamous Acherontia atropos, (L. 1758) - undoubtedly the most famous lepidopteran amongst cinema buffs worldwide.

A flawed gem

2010-04-17T02:28:00.009+02:00

Luria lurida (Linn., 1758) is a common snail from the family Cypraeidae found in shallow Maltese waters. The specimen above was very timid and did not emerge from its shell fully, even after 30 minutes of waiting on my part. However, the tip of the siphon can be seen on the right hand side, together with a very small part of the mantle covering the shell's edge.

Gastropods happen to be a favourite food of their far more cunning relative, the octopus. An octopus can usually pull other snails right out of their shell, but L. lurida has a narrow aperture and is well-protected in this regard. Besides, it withdraws deeply into its shell, beyond significant reach of the octopus' tentacles. The octopus therefore resorts to drilling a hole in the shell with its tongue, enabling it to secrete enzymes and extract the animal (Wodinsky, 1969).

Such drill-holes are commonly found on beached L. lurida, as can be seen in the photograph below.

Wodinsky, J., 1969. Penetration of the shell and feeding on gastropods by Octopus. American Zoologist, 9 (3): 997-1010.

Bugs!

2010-04-14T01:32:00.005+02:00

Few arthropods have appeared on this blog so far, so here's a trio of specimens from that marvellous group known as the Coleoptera:

Ocypus olens (Müller, 1764) Għallis Point 31.X.2009

Oxythyrea funesta (Poda, 1761) - Chadwick Lakes, 25.II.2010

Blaps gigas (Linné, 1767) - Għajn Tuffieħa 23.IX.2009

According to biologist J. B. S. Haldane, if a Creator exists he must have 'an inordinate fondness for beetles'*. Whatever one's religious persuasions (or dissuasions) are, there can hardly be any doubt about the accurate implications of his statement.

*Hutchinson, G. E., 1959. Homage to Santa Rosalia or why are there so many kinds of animals?. American Naturalist, 93: 145-159.

Living snails from Malta - update

2010-04-10T03:34:00.003+02:00

Additional photographs of live snails are now available on the Associazione Malacologica Internazionale's website, accessible through my earlier post here.

More on Pleistocene rodents

2010-04-09T02:07:00.017+02:00

Dorothea Bate (1878-1951) was a British explorer and palaeontologist whose main interests were Mediterranean Pleistocene mammals. The first woman scientist to hold a permanent post at the Natural History Museum in London, she discovered and named a number of new species from Crete, Cyprus, Malta and the Balearic Islands.

Two Pleistocene vole species bearing her authorship are known from deposits in Għar Dalam, Malta. Voles, from the rodent family Cricetidae, are very similar to mice, but have a stouter body and a hairy tail. They are nowadays extinct from the Maltese Islands - Gulia (1858; 1890) and some subsequent authors list the vole Arvicola amphibius (L., 1758) as occurring in Malta, but this statement is not supported in any way, either by more recent authors on mammals (Lanfranco, 1969) or by the present writer's observations.

The fossil species named by Dorothea Bate are Terricola melitensis (Bate, 1920) and Terricola pauli (Bate, 1935), both originally placed in the Pitymys genus before it was known that this actually indigenous to North America (Chaline et al., 1999, Kotsakis, 2004). T. melitensis is closely related to Terricola savii (de Sélys-Longchamps, 1838), shown above, which nowadays lives mainly along the Italian peninsula (Brunet-Lecomte & Chaline, 1992; Chaline et al., 1999; Wilson & Reeder, 2005). T. pauli is a large enigmatic species with less obvious affinities, and indeed with a name not encountered much in the literature. The figure of the holotype from Bate's original description is reproduced below.

References:

Bate, D. M. A., 1920. Note on a new vole and other remains from the Ghar Dalam Cavern, Malta. Geological Magazine, 57: 208-211.

Bate, D. M. A., 1935. Two new mammals from the Pleistocene of Malta, with notes on the associated fauna. Proceedings of the Zoological Society of London, 247-264.

Brunet-Lecomte, P. & Chaline, J., 1992. Morphological convergences versus biochemical divergences in the holarctic ground voles: Terricola and Pitymys (Arvicolidae, Rodentia). Neues Jahrbuch für Geologie und Paläontologie, 12: 721-734.

Chaline, J., Brunet-Lecomte, P., Montuire, S., Viriot, L., & Courant, F., 1999. Anatomy of the arvicoline radiation (Rodentia): palaeogeographical, palaeoecological history and evolutionary data. Annales Zoologici Fennici, 36: 239–267.

Gulia, G., 1858. Repertorio di Storia Naturale. Malta, 68 pp.

Gulia, G., 1890. Elenco dei Mammiferi Maltesi. Il Naturalista Maltese, 1 (1): 2-3.

Kotsakis, T., 2004. The Plio-Pleistocene rodents of the Mediterranean islands: origin and evolution. 18th Senckenberg Conference 2004 in Weimar.

Lanfranco, G., 1969. Maltese mammals (Central Mediterranean). Malta: Progress Press, 36 pp.

Wilson, D. E. & Reeder, D. M. [eds], 2005. Mammal Species of the World - A Taxonomic and Geographic Reference [3rd edition]. Johns Hopkins University Press, 142 pp.

Picture of Terricola savii (de Sélys-Longchamps, 1838) from http://www.cogecstre.com/Vertebrati/images/ArvicolaDiSavi.jpg