The blood of mollusks contains a special chemical called hemocyanin, which helps carry oxygen throughout the bloodstream. [78] The first mollusc shell almost certainly was reinforced with the mineral aragonite.[28]. which part of the mollusk body contains organs? Which part of the mollusk body contains organs? Which class of Mollusks have the most advanced nervous system? [51] In one particular branch of the family tree, the shell of conchiferans is thought to have evolved from the spicules (small spines) of aplacophorans; but this is difficult to reconcile with the embryological origins of spicules. which part of the mollusk body contains organs? Professor of Zoology, University of Vienna. Phylum Mollusca: Digestive, Nervous & Circulatory Systems Click, SCI.BIO.755 (Mollusk Structure and Function - Biology). To use this website, please enable javascript in your browser. Blue-ringed octopuses in the genus Hapalochlaena, which live around Australia and New Guinea, bite humans only if severely provoked,[97] but their venom kills 25% of human victims. They are masters of optical illusion. Mollusks live in most terrestrial, freshwater, and marine habitats. What is a mollusk? The organs filter waste from body fluids and release the waste into the coelom. answer choices They are protostome acoelomates They are protostome coelomates They are deuterostome coelomates They are protostome pseudocoelomates Question 3 120 seconds Q. Shell is secreted by a special skin called mantle that covers soft visceral mass. We also acknowledge previous National Science Foundation support under grant numbers 1246120, 1525057, and 1413739. Many shell-bearing molluscan species are also used to fabricate ornaments and are harvested for the pearl and mother-of-pearl industries. The "generalized" mollusc's feeding system consists of a rasping "tongue", the radula, and a complex digestive system in which exuded mucus and microscopic, muscle-powered "hairs" called cilia play various important roles. ; Garca-lvarez, O.L. The main distinguishing feature is a hard outer shell. The Humboldt squid usually lives in the waters of the Humboldt Current, ranging from the southern tip of South America north to California, but in recent years, this squid has been found as far north as Alaska. Their mouth, also like humans, contains teeth as part of an oral structure called a radula. The tiny specimens have been suggested to be juveniles and the larger ones adults.