How did bivalves get their name?
The name “bivalve” refers to the two-part shell that characterizes these mollusk species. The two halves of the shell are joined by a ligamentous hinge and held shut by a pair of strong adductor muscles. The shell is made of calcium carbonate and is secreted by the mantle (soft body wall).
What makes a bivalve a bivalve?
Bivalves have two shells, connected by a flexible ligament, which encase and shield the soft vulnerable parts of the creature. All 15,000 known species of bivalves are aquatic in nature, with close to 80% being marine (saltwater environments).
Is a clam a bivalve or Univalve?
Gastropods are also called univalves. Bivalves, which include but are not limited to clams, oysters, mussels, and scallops, have two shells, which are joined together at one side by a hinge. The living bivalve animal has strong muscles that are affixed to the shells and control opening and closing of the valves.
What’s the difference between clams and bivalves?
Clams are bivalve shellfish that live in either fresh or salt water. They have hard shells that are smooth and shiny. In contrast, mussels live in fresh or salt water, having shells that are oval in shape and elongated at the ends.
What does the word bivalve?
: being or having a shell composed of two valves. bivalve. noun. Definition of bivalve (Entry 2 of 2) : any of a class (Bivalvia synonym Pelecypoda) of typically marine mollusks (such as clams, oysters, or scallops) that have a 2-valved hinged shell, are usually filter feeders, and lack a distinct head.
What is the function of the mantle in a clam?
The mantle cavity is a central feature of molluscan biology. This cavity is formed by the mantle skirt, a double fold of mantle which encloses a water space. This space contains the mollusk’s gills, anus, osphradium, nephridiopores, and gonopores. The mantle cavity functions as a respiratory chamber in most mollusks.
What type of creature is a gastropod?
The Class Gastropoda (in Phylum Mollusca) includes the groups pertaining to snails and slugs. The majority of gastropods have a single, usually spirally, coiled shell into which the body can be withdrawn. The shell of these creatures is often what is recovered in a fossil dig.
What defines bivalve?
Bivalve mollusks (e.g., clams, oysters, mussels, scallops) have an external covering that is a two-part hinged shell that contains a soft-bodied invertebrate. As filter feeders, bivalves gather food through their gills.
What gastropod means?
Definition of gastropod : any of a large class (Gastropoda) of mollusks (such as snails and slugs) usually with a univalve shell or none and a distinct head bearing sensory organs.
Why are clams referred to as bivalves in science?
Clams are called bivalves because they have two separate parts to their shells. The two segments are held together by connective tissue that the clam… See full answer below.
What kind of shells does a bivalve have?
Bivalves are known by a variety of common names, depending on species, or species group; Clams, Cockles, Fan Shells, Mussels, Oysters, Scallops and Shipworms are all species of bilvalves. Bivalves are aquatic molluscs that possess two shells that are connected by a hinge. The two shells are commonly referred to as valves.
How does a bivalve fish get its food?
A roughfile clam from the Flower Garden Bank National Marine Sanctuary—just one of many different bivalve mollusk species. Like fish, bivalve mollusks breathe through their gills. As filter feeders, bivalves gather food through their gills.
Which is the largest family of bivalves in the world?
The largest recent marine families are the Veneridae, with more than 680 species and the Tellinidae and Lucinidae, each with over 500 species. The freshwater bivalves include seven families, the largest of which are the Unionidae, with about 700 species.
