An animal with no backbone. • The smallest bivalves are microscopic and the largest are 4 feet across. Tags: Question 5 . Bivalve, (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. • Most bivalves are filter feeders taking all floating particles out of the water column. andielj7508. There is a layer of tissue called the mantle between the shell and the body. Save. valvia = shell : These mollusks have two shells hinged together by a ligament. This class of mollusks is considered to be the most intelligent. a large bivalve that can weigh over 200kg. bivales. bi = two. SURVEY . ... (seashells) includes clams oysters and scallops. Class Bivalvia • This class includes: clams, mussels, scallops, oysters, cockles, and jingle shells. arthropods. A member of the class polyplacophora (Mollusks with many shells) (6) Ammonite. Mollusks also have a coelom, a complete digestive system, and specialized organs for excretion. gastropods. Mollusks have been evolving in the sea for over 600 million years and there are more than 100,000 mollusks species. answer choices . 10 times. 87% average accuracy. 9th grade. Mollusks are members of the phylum mollusca. • The only class of molluscs that has two shells. Some examples of bivalves are oysters, clams, mussels, and scallops. We can look at two subcategories to find examples of mollusks with shells. Current and excurrent siphons circulate water containing food and oxygen through the bivalve. Bivalves have two shells that are hinged on one side, allowing them to open and close. Giant clam. Invertebrate. They have two hinged shells that close around the animal for protection. cephalopods. CLASS BIVALVIA. A cephalopod with 8 arms. Mollusks with two shells are known to the world as bivalves. 8 months ago. 900 seconds . Strong adductor muscles open and close the shells. Edit. The monoplacophorans were believed extinct and only known as fossils until the discovery of Neopilina galatheae in 1952. Tusk shells, also known as scaphopods, have long, cylindrical shells with tentacles extending from one end, which these mollusks use to rope in prey from the surrounding water. The majority of mollusks live in the ocean. They were long believed to be extinct, but in 1952, zoologists discovered a handful of living species. An extinct cephalopod with an extensive fossil record. Mollusks have a hard outer shell. Chiton. Monoplacophorans are deep-sea mollusks equipped with cap-like shells. The two, 'bi', shells are also called valves, which is how these mollusks got their name. Science. ... Squid. Mollusks that have 2 hinged shells belong to which class. Cephalopoda. The valves are connected to one another at a hinge. Bivalvia have two identical shells that are hinged together. 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