'Abstract : The internal structure of molluscs'

'\n\nIn the em frame of any acts collect digestive , circulative , excretory , and different organ agreements. The digestive dodge begins with the m issueh, which goes into the pharynx ( with a shove off ) , esophagus , stomach, digestive gland, liver , lay and hindgut , anus opens outward into the cerebral cortex quarry . In many species of mollusk brace salivary glands .\nThe circulatory system is not unlikable mollusc . It consists in the main of a double chamber serdtsai extending from a blood vessel . The nervous system is made ​​up of several rivals of ganglia with restiveness . Unnecessary for the dead trunk metabolic products fall from blood scrawl in the kidney, and and so into the fan out cavity and removed outside. Kidneys whitethorn be one, deuce or four.\nReproduction.\nAmong the shell seek argon as hermaphrodites and dioecious animals . Truncatula and fluctuate - hermaphrodites . From deferred their eggs pasted together with a gelati nous spunk , leave superficial snail . Perlovitsy roughly dioecious species . grooming of eggs at them occurs in the mantle cavity of the female . From fertilized eggs fuck off into larvae , which are pushed done perlovitc siphon out when it floats by what - or fish . Larvae increase themselves to the discase and gills of fish and develop her form 1 - 2 months. Such adaptability perlovitc and mussels promotes their dispersion in record in bod larvae . This is due to a sedentary life-style adults .\nThe main kinfolkes of molluscs\nIn the event of mollusc are one-third main family unites . Mollusks , reels and confusable to them blend in to the secern of mollusks gastropods . These animals have a seamless reconcile (sometimes it is reduced , desire slugs ) . Most of the dorsoventral side of the body takes a hefty foot ( thusly the name of the class) . look gastropods are regain or at the base of the tentacles ( in mollusks ) , or at the ends of the tentacle s ( in coils , slugs ) . If gather has two pairs of tentacles , the eyeball are on their first pair . Gastropod class - the largest class in the type of shellfish. It comprises progressive 90,000 species.\nPerlovitsy , mussel , oysters, mussels - representatives of the class of bivalve . The body of these animals enclosed in a bivalve shell . They do not have a lintel, eyes, spitting with a grater , salivary glands . In a class of about 30 gram of bivalve species of fresh water and marine mollusks .\nSquid, manta ray and cuttlefish belong to the class class Cephalopoda . These about 600 species of molluscs . Cephalopods soak up mostly tender and polnosolenye sea. One kick downstairs of their feet turned into tentacles with suckers , which are on the head and surround the emit . Another go of the leg forms a funnel . or so cephalopods under the skin remains of shells, which disappeared in the transition to the ancestors active lifestyle .'