SNAILS BY Alex Pritchard EULIMIDS The eulimids are
SNAILS BY: Alex Pritchard
EULIMIDS • The eulimids are a family of snails which are almost always parasites. Most species have evolved to live with a particular echinoderm (starfish, sea-urchin, brittle-star, sea-cucumber). This unnamed species from New Caledonia lives on this brittle-star. It feeds on the brittle-star by drilling into its body. The white sacs are the eulimid's egg sacs (2 mm).
Physical Characteristics • Most snails move by gliding along on their muscular foot, which is lubricated with mucus. This motion is powered by succeeding waves of muscular contraction which move down the undersurface of the foot. • Snails range greatly in size. The largest land snail is the Giant African Snail or Ghana Tiger Snail (Achitina; Family Achitinadea), which can measure up to 30 cm.
• The most common aquarium snails are gilled snails. These include the common pond snail, and ramshorns and Malayan livebearing snails. All of these snails can get well populated in the aquarium. Gilled snails are hermaphroditic but not all of them in the same way. Some species change sex, some fertilize their own eggs and some cross fertilize. Most of these snails lay eggs in gelatin masses attached to submerged rocks, plants and other surfaces. The Malayan livebearing snail is an exception.
Stuff about Shells • Most members have a shell, which is in one piece and is typically coiled or spiraled. This coiled shell usually opens on the right hand side (as viewed with the shell apex pointing upward). Several species have an operculum which in many species is a sort of a trapdoor to close the shell. This is usually made of a horn-like material, but in some mollusks it is calcareous. In the land slugs, the shell is reduced or absent, and the body is streamlined.
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