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The highly modified parasitic genus Enteroxenos has no digestive tract at all, and simply absorbs the blood of its host through the body wall. [1] The digestive system usually has the following parts: buccal mass (including the mouth, pharynx, and retractor muscles of the pharynx) and salivary glands with salivary ducts; oesophagus and ...
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.
The hinge area is the dorsum or back of the shell. The lower, curved margin is the ventral side. The anterior or front of the shell is where the byssus and foot are located (if the animal has these structures) and the posterior or back of the shell is where the siphon is located (again, if present— the scallops, for example, do not have ...
Front endpaper About 200,000 living species in total are estimated, [3] [24] and 70,000 fossil species, [17] although the total number of mollusc species ever to have existed, whether or not preserved, must be many times greater than the number alive today. [25] Molluscs have more varied forms than any other animal phylum.
In species where the shell is small compared to the size of the body, more of the mantle shows. Shell-less slugs have the mantle fully visible. The dorsal surface of the mantle is called the notum, while the ventral surface of the mantle is called the hyponotum. In the family Philomycidae, the mantle covers the whole back side of the body. [2]
Pages in category "Mollusc anatomy" The following 35 pages are in this category, out of 35 total. This list may not reflect recent changes. A. Aesthete (chiton)
The internal anatomy is visible, including the paired siphons to the right. A siphon is an anatomical structure which is part of the body of aquatic molluscs in three classes: Gastropoda, Bivalvia and Cephalopoda (members of these classes include saltwater and freshwater snails, clams, octopus, squid and relatives).
[9] [10] At the dorsal or back region of the shell is the hinge point or line, which contain the umbo and beak and the lower, curved margin is the ventral or underside region. The anterior or front of the shell is where the byssus (when present) and foot are located, and the posterior of the shell is where the siphons are located. With the ...