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Megalonaias Nervosa
''Megalonaias nervosa'' is a freshwater mussel species in the family Unionidae The Unionidae are a family of freshwater mussels, the largest in the order Unionida, the bivalve molluscs sometimes known as river mussels, or simply as unionids. The range of distribution for this family is world-wide. It is at its most diverse .... Washboard is the common name used for ''Megalonaias nervosa''. Description The shell is divided into two valves that are hinged. Shell is thick and rectangular in shape and can be compressed or inflated; umbos do not extend above the hinge line (Cicerello, R. and Schuster, G. 2003). The cardinal teeth are large and serrated, while the lateral teeth are long and curved. Shell color ranges from dark brown to black and is covered with small bumps and has fluted ridges: nacre is white to gray color. Life Cycle: Megalonaias nervosa mussels are sexually mature around 8 years of age, they are late tachytictic breeders. From July to October the males are matu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Unionidae
The Unionidae are a family of freshwater mussels, the largest in the order Unionida, the bivalve molluscs sometimes known as river mussels, or simply as unionids. The range of distribution for this family is world-wide. It is at its most diverse in North America, with about 297 recognised taxa, but China and Southeast Asia also support very diverse faunas. Freshwater mussels occupy a wide range of habitats, but most often occupy lotic waters, i.e. flowing water such as rivers, streams and creeks. Origin and early diversification The recent phylogenetic study reveals that the Unionidae most likely originated in Southeast and East Asia in the Jurassic, with the earliest expansions into North America and Africa (since the mid-Cretaceous) followed by the colonization of Europe and India (since the Paleocene). Life history Unionidae burrow into the substrate, with their posterior margins exposed. They pump water through the incurrent aperture, obtaining oxygen and food. They remove ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |