Endangered Species Day 2011

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

Species spotlight XI

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

Gozo crocodiles

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.

Some views of Ramla l-Ħamra, N Gozo

Crystal clear

These images show the mineral selenite, which is an aggregate of calcium sulphate crystals locally found in the Blue Clay Formation. Photo from Mġarr, Għawdex.