The main muscular system in bivalves is the posterior and anterior adductor muscles. These muscles connect the two valves and contract to close the shell. ... Bivalves have an open circulatory system that bathes the organs in blood . The heart has three chambers: two auricles receiving blood from the gills, and a single … See more Bivalvia , in previous centuries referred to as the Lamellibranchiata and Pelecypoda, is a class of marine and freshwater molluscs that have laterally compressed bodies enclosed by a shell consisting of two hinged parts. As a … See more Bivalves have bilaterally symmetrical and laterally flattened bodies, with a blade-shaped foot, vestigial head and no radula. At the dorsal or back region of the shell is the hinge point or … See more The Cambrian explosion took place around 540 to 520 million years ago (Mya). In this geologically brief period, all the major animal phyla diverged and these included the first creatures … See more The bivalves are a highly successful class of invertebrates found in aquatic habitats throughout the world. Most are infaunal and live buried in sediment on the seabed, or in the sediment in freshwater habitats. A large number of bivalve species are found in the See more The taxonomic term Bivalvia was first used by Linnaeus in the 10th edition of his Systema Naturae in 1758 to refer to animals having shells composed of two valves. More recently, the class was known as Pelecypoda, meaning "axe-foot" (based on the … See more Brachiopods are shelled marine organisms that superficially resembled bivalves in that they are of similar size and have a hinged shell in two parts. However, brachiopods evolved from a very different ancestral line, and the resemblance to bivalves only arose … See more The adult maximum size of living species of bivalve ranges from 0.52 mm (0.02 in) in Condylonucula maya, a nut clam, to a length of 1,532 … See more WebThe digestive system of a bivalve is fairly simple, similar to a worm's, a far cry from the human digestive system. An open circulatory system, heart, and nerves round out the main bulk...

28.3F: Classification of Phylum Mollusca - Biology LibreTexts

WebAnatomy of the nervous system in bivalves. It is decentralized and consists of bilaterally symmetrical cerebral ganglia (CG), pedal ganglia (PG), and visceral ganglia (VG). Webbivalve, (class Bivalvia), any of more than 15,000 species of clams, oysters, mussels, scallops, and other members of the phylum Mollusca characterized by a shell that is divided from front to back into left and right valves. The valves are connected to one another at a … lowest tax eu countries

15.4 Mollusks and Annelids - Concepts of Biology OpenStax

WebThe molluscan circulatory system is composed of a series of blood sinuses or cavities, rather than closed, discrete vessels. This is referred to as an open circulatory system. Molluscs display a large diversity of … WebClass Bivalvia – clams, oysters, mussels, scallops, cockles, shipworms, etc. ... In terms of circulation, all cephalopods have a closed circulatory system. Blood is pumped to the body by a centrally located systemic heart (11). After delivering its oxygen to the squid's tissues, poorly oxygenated blood is returned to the gills via an anterior ... lowest taxes on cape cod