Search results
Results from the WOW.Com Content Network
Freshwater bivalves are molluscs of the order Bivalvia that inhabit freshwater ecosystems. They are one of the two main groups of freshwater molluscs , along with freshwater snails . The majority of bivalve molluscs are saltwater species that live in the marine habitats , but a number of families have evolved to live in fresh water (and in some ...
Bivalvia (/ b aɪ ˈ v æ l v i ə /) or bivalves, in previous centuries referred to as the Lamellibranchiata and Pelecypoda, is a class of aquatic molluscs (marine and freshwater) that have laterally compressed soft bodies enclosed by a calcified exoskeleton consisting of a hinged pair of half-shells known as valves.
Bivalve molluscs are used as bioindicators to monitor the health of aquatic environments in both fresh water and the marine environments. Their population status and structure, physiology, behaviour and their levels of contamination with chemicals together provide a detailed indication of the status of the ecosystem.
There are about 8,000 marine bivalves species (including brackish water and estuarine species), and about 1,200 freshwater species. Cephalopod include octopus , squid and cuttlefish . They are found in all oceans, and neurologically are the most advanced of the invertebrates. [ 59 ]
Unionidae burrow into the substrate, with their posterior margins exposed. They pump water through the incurrent aperture, obtaining oxygen and food. They remove phytoplankton and zooplankton, as well as suspended bacteria, fungal spores, and dissolved organic matter.
Velesunio wilsonii come from one of two classes of molluscs that have successfully inhabited freshwater ecosystems. [1] All other mollusc classes remain in marine ecosystems . [ 1 ] Bivalve molluscs evolved in marine ecosystems before slowly moving into estuaries and inhabiting upstream freshwater habitats, evolving to tolerate lower salinity ...
One bivalve group, the rudists, became major reef-builders in the Cretaceous, but became extinct in the Cretaceous–Paleogene extinction event. [26] Even so, bivalves remain abundant and diverse. The Hyolitha are a class of extinct animals with a shell and operculum that may be molluscs.
Mussel (/ ˈ m ʌ s ə l /) is the common name used for members of several families of bivalve molluscs, from saltwater and freshwater habitats. These groups have in common a shell whose outline is elongated and asymmetrical compared with other edible clams, which are often more or less rounded or oval.