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Dreissena Rostriformis Distincta
'' Dreissena rostriformis distincta '' is a (possible) subspecies of freshwater mussel, an aquatic bivalve mollusk in the family Dreissenidae The Dreissenidae are a family of small freshwater aquatic bivalve molluscs, commonly called ''mussels'' although not at all closely related to true mussels. The shells of these bivalves are shaped somewhat like those of true mussels, which they .... It was originally described in 1897 as a variety of ''D. rostriformis'' by Andrusov (Andrusov, 1897: 273-276, pl. 14, figs. 18-24.) The type locality was numerous localities in the Volga River, Caspian, Black and Marmara seas (both Recent and fossil). However, the exact taxonomy of the species within the genus ''Dreissensa'' is uncertain. As Kantor et al. commented, "...the Russian specialists on fresh-water molluscs appeared to be “splitters” comparing with their western colleagues. This sometimes leads to extreme differences in opinion on species number and taxonomy of some groups."Ka ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Freshwater Mussel
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 cases, also in brackish water). These belong to two different evolutionary lineages, i.e. freshwater mussels and freshwater clams, and the two groups are not closely related. Freshwater bivalves have a simple morphology that varies among taxa, and are distributed around most regions of the world. Freshwater bivalve species vary greatly in size. Some pea clams (genus '' Pisidium'') have an adult size of only . In contrast, one of the largest species of freshwater bivalves is the swan mussel from the family Unionidae; it can grow to a length of , and usually lives in lakes or slow-flowing rivers. Freshwater pearl mussels are economical ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aquatic Animal
An aquatic animal is any animal, whether vertebrate or invertebrate, that lives in a body of water for all or most of its lifetime. Aquatic animals generally conduct gas exchange in water by extracting dissolved oxygen via specialised respiratory system, respiratory organ (biology), organs called gills, cutaneous respiration, through the skin or enteral respiration, across enteral mucosae, although some are evolution, evolved from terrestrial ancestors that re-adaptation, adapted to aquatic environments (e.g. marine reptiles and marine mammals), in which case they actually use lungs to breathing, breathe air and are essentially apnea, holding their breath when living in water. Some species of gastropod mollusc, such as the Elysia chlorotica, eastern emerald sea slug, are even capable of kleptoplastic photosynthesis via endosymbiosis with ingested yellow-green algae. Almost all aquatic animals reproduce in water, either oviparously or viviparously, and many species routinely fish ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bivalve
Bivalvia () or bivalves, in previous centuries referred to as the Lamellibranchiata and Pelecypoda, is a class (biology), class of aquatic animal, aquatic molluscs (marine and freshwater) that have laterally compressed soft bodies enclosed by a calcified exoskeleton consisting of a hinged pair of half-bivalve shell, shells known as valve (mollusc), valves. As a group, bivalves have no head and lack some typical molluscan organs such as the radula and the odontophore. Their gills have evolved into ctenidium (mollusc), ctenidia, specialised organs for feeding and breathing. Common bivalves include clams, oysters, Cockle (bivalve), cockles, mussels, scallops, and numerous other family (biology), families that live in saltwater, as well as a number of families that live in freshwater. Majority of the class are benthic filter feeders that bury themselves in sediment, where they are relatively safe from predation. Others lie on the sea floor or attach themselves to rocks or other h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mollusk
Mollusca is a phylum of protostomic invertebrate animals, whose members are known as molluscs or mollusks (). Around 76,000 extant species of molluscs are recognized, making it the second-largest animal phylum after Arthropoda. The number of additional fossil species is estimated between 60,000 and 100,000, and the proportion of undescribed species is very high. Many taxa remain poorly studied. Molluscs are the largest marine phylum, comprising about 23% of all the named marine organisms. They are highly diverse, not just in size and anatomical structure, but also in behaviour and habitat, as numerous groups are freshwater and even terrestrial species. The phylum is typically divided into 7 or 8 taxonomic classes, of which two are entirely extinct. Cephalopod molluscs, such as squid, cuttlefish, and octopuses, are among the most neurologically advanced of all invertebrates—and either the giant squid or the colossal squid is the largest known extant i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dreissenidae
The Dreissenidae are a family of small freshwater aquatic bivalve molluscs, commonly called ''mussels'' although not at all closely related to true mussels. The shells of these bivalves are shaped somewhat like those of true mussels, which they also resemble in attaching themselves to a hard substrate such as stone using a byssus; however, this group is more closely related to the venus clams (Veneridae). Genera Genera within the family Dreissenidae include: * '' Congeria'', a unique genus of cave-dwelling bivalves * '' Dreissena'', the type genus of the family * '' Mytilopsis'' * '' Rheodreissena'', a South American genus described in 2018 Shell morphology The shells of species of mussels in this family range from 20 to 40 mm in their maximum dimension, and about half as wide across. The shell outline is bent, with one margin usually somewhat incurved, and the other strongly curved outwardly. The shell is opaque and robust; in coloration it is yellowish, brownish or greyi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
