Waiter, there's a snail in my paella

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.

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.