A
Sicilo-Caribbean Kety Nicolay Last year, during
the months of April and May, my husband and I went to the Cayman Island (Caribes) : that
journey was not simply a period of holidays in the tropical seas, but was aimed at a
malacological research in an area that was still unknown to us. I must immediately say that, from this point
of view, Grand Cayman disappointed us greatly: we spent several hours sifting the beaches
of that island, and even more in the sea, searching under the rocks and among the algae of
the bottoms, with really scarce result. If we except some interesting Chiton, the
only molluscs collectable appeared to be Strombus gigas L.,1758, Tectarius
muricatus L.,1758 and - but not as common as the other two already mentioned - Cyphoma
gibbosum L.,1758. On the other hand, the number of the specimens, especially of the
first two species, is huge: you can find everywhere beached shells of S. gigas,
almost all presenting the typical round hole on the whorl which tells us that mollusc has
been used for alimentary purposes. In spite of the laws of many States ( Italy included ) for which S.
gigas is a protected species, this molluscs is found in the Menus of all the
Restaurants of the island under the name of "Queen’s Conch" . And about the
gracious littorinid T. muricatus, whose pretty shell is crammed with small
granulate spiral cords, the whole rocky coast of the island appears to be colonized by it;
many individuals, not having found a place in the interdidal area, live even at a few
dozens of meters from the sea breaker.  06/27/93, Size: 18 mm. height, width of the base 7.5 mm.Habitat: "Baby K." has been placed on some sea stones, in a plastic basin ( see fig.1) together with some Mediterranean Littorines: Littorina neritoides (L.,1758) and Littorina punctata (Gmelin, 1791).
She eats
regularly the same alga (Ulva lactuca, or Sea lattuce) and she copulates, odd by
true!, with L. punctata, having chosen as a partnerthe biggest specimen of this
species inside the same plastic basin.
This shows that "Baby K." settled perfectly to our climate, to
the quality of sea-water and to the diet of Mediterranean algae: and in fact her growth
rate is really remarkable. It would be particulary interesting to compare these data with
the growth data of other T. muricatus of the same size remained in their
birthplace, but unfortunately these data are not avaiable. We are sincerely grateful to Vanna for her patience in collecting the observations we just synthesized for you. This group of gregarious
and onnipresent Mesogastropoda (they live in settlements often very numerous, in all the
seas of the world, with warm, temperate and cold waters, except for the extreme tip of
Southern America) includes about a hundred species, grouped in about twenty genera and
five subfamilies. They inhabit littorals (from this, the name) both rocky and marshy, with
mangroves, of the tropical regions; usually they live in the intertidal zone, but often
they live also beyond this area. The special shape of their gills and the perfect seal of
their strong horny operculum let the molluscs live even in dry habitat, although they are
indissolubly linked with sea by their reproductive cycle. It is easy to observe the life
cycle of these molluscs; this fact, and their abundance, made this group become one of the
most studied. As a consequence, there is an impressive literature on this subject, but
there is no reason to quote it here.
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