Search results
Results From The WOW.Com Content Network
A slug on a wall in Kanagawa, Japan.. Slug, or land slug, is a common name for any apparently shell-less terrestrial gastropod mollusc.The word slug is also often used as part of the common name of any gastropod mollusc that has no shell, a very reduced shell, or only a small internal shell, particularly sea slugs and semi-slugs (this is in contrast to the common name snail, which applies to ...
Molluscs are a large phylum of invertebrate animals, many of which have shells. Edible molluscs are harvested from saltwater, freshwater, and the land, and include numerous members of the classes Gastropoda (snails), Bivalvia (clams, scallops, oysters etc.), Cephalopoda (octopus and squid), and Polyplacophora (chitons).
The shell ranges from 3 mm to 37 mm in diameter depending on species. Like in chitons , the head is poorly defined, and there are no eyes. The mouth is located within the animal's undeveloped head in front of its single large foot and contains a radula , a defining characteristic of the mollusca.
The generalized mollusc is an unsegmented, bilaterally symmetrical animal and has a single, "limpet-like" shell on top. The shell is secreted by a mantle covering the upper surface. The underside consists of a single muscular "foot". [19] The visceral mass, or visceropallium, is the soft, nonmuscular metabolic region of the mollusc.
Mollusca is a phylum of protostomic invertebrate animals, whose members are known as molluscs or mollusks (/ ˈ m ɒ l ə s k s /). Around 76,000 extant species of molluscs are recognized, making it the second-largest animal phylum after Arthropoda .
The mystery mollusks are hermaphrodites, which include both male and female reproductive organs. When it is time to release eggs, they descend and use their foot to temporarily attach to the seafloor.
In contrast to many other mollusc classes, aplacophorans have no shell, and are instead covered by aragonitic sclerites (calcareous spicules), which can be solid or hollow.. These spicules can be arranged perpendicular to one another within the cuticle to form a skeleton, stick up to form a palisade, or can lie flat against the cutic
The mollusc (or mollusk [spelling 1]) shell is typically a calcareous exoskeleton which encloses, supports and protects the soft parts of an animal in the phylum Mollusca, which includes snails, clams, tusk shells, and several other classes. Not all shelled molluscs live in the sea; many live on the land and in freshwater.