From the blogosphere

This blog has been featured in a post on the Nature Blog Network. The site features several interesting links and is strongly recommended as a starting point for the exploration of nature as featured through blogs from around the world.

Meanwhile, the crew at That's Rubbish! are doing a great job at their commitment to disseminate environmental awareness in Malta, showing that actions speak louder than words (and all the same hosting interesting articles on their blog).

Another cold-blooded encounter

This beautiful reptile, from the Qbajjar area in Western Gozo, is a juvenile specimen of the Western Whip Snake, Hierophis viridiflavus (Lacépède, 1789). It shows a different colour than sexually mature adults, which are of an intense black colour (P. J. Schembri, pers. comm. III.2010).

A meeting of old and new

Sphincterochila candidissima (Draparnaud, 1801) is a very noticeable denizen of seaside cliffs and coralline karsts of the central Mediterranean. Right now (in addition to a period in late October-November) this species is highly active in Malta, with most reproduction and egg-laying taking place in time before the imminent summer season forces the animals to aestivate.

The snails are white for optimum reflection of heat, and construct hardy epiphragms (aperture coverings) from mucus and calcite dust, which prevent considerable water loss by evaporation.

The photograph shows a live mature individual, resting next to the long-dead shell of a presumed ancestor. The latter is embedded in a Holocene rupestral deposit. The specimens come from a small population at Rdum tal-Madonna, Mellieħa.

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.

New project uploaded

A small website required for a University assignment has been uploaded at the link pasted below:

Maltese Endemic Landsnails

Virtually all photographs included are appearing on the web for the first time.

The website expires this year, so I will upload the content here as soon as that occurs.

Back to basics

The isopods are the perfect example of crustaceans that have adapted to life in a terrestrial habitat. However, some of them have opted for a return to the aquatic world, an evolutionary move which finds parallels in other animal groups as diverse as molluscs, reptiles and mammals.

The above picture shows the woodlouse Sphaeroma sp., found beneath a rock in the Salini marshes, a unique ecosystem which features one of the very few brackish water habitats in the Maltese Islands.

It came, it saw, it conquered

The non-native Otala punctata (Müller, 1774) is a helicid snail which was imported into Malta through a plant nursery in Mosta. The established population was studied in 2008 by Barbara & Schembri, who mapped its range around the nursery responsible for its introduction. This map is copied and pasted beneath; the part highlighted in yellow by Barbara & Schembri shows the range of the species as in 2008. The red shows the plant nursery itself, while the dark grey shows the studied area.

Today, a substantial number of specimens was found further to the north of the yellow area. I have covered the 'newly colonized' area in blue to give an indication as to its extent. Apparently this snail is very well adapted to the kind of anthropogenically disturbed habitat presented in the vicinity, and will continue to colonize new areas and advance as predicted in the 2008 paper. The larger its range becomes, the less anything can be done to exterminate it, which is very bad news for native (and less aggressively competitive) snails.

*The photograph of the Otala punctata specimen above was taken at point 'a'.

Reference:

Barbara N. & Schembri P. J., 2008. The status of Otala punctata (Müller, 1774), a recently established terrestrial gastropod in Malta. Bollettino Malacologico, 44 (5-8): 101-107.

A cold-blooded encounter

This is the skink Chalcides ocellatus Forsskål, 1775, a circum-Mediterranean species known in Maltese as Xaħmet l-Art. This specimen is from Żejtun and is obviously still juvenile.

More information about the author of this species can be found in my older post here.

More alien blobs

Almost a mere month after the first record of the jellyfish Cassiopea andromeda from Malta, a new cnidarian species is confirmed as existing in our waters.

This time, far from being anything harmless as in the above-mentioned case, the culprit is the painful stinger Physalia physalis (L., 1758), a hydrozoan (not a true jellyfish) known better as the Portuguese Man-Of-War. The species is more or less frequent in the Atlantic Ocean and only ventures into the Mediterranean occasionally.

The sighting at Ċirkewwa was fortunately recorded on camera by Mr. Adrian Buttigieg, lending more credibility to accounts of sightings off St. Paul's Bay in 2009.