| Megalonaias nervosa | |
|---|---|
 | |
| Museum specimen | |
Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Mollusca |
| Class: | Bivalvia |
| Order: | Unionida |
| Family: | Unionidae |
| Genus: | Megalonaias |
| Species: | M. nervosa |
| Binomial name | |
| Megalonaias nervosa (Rafinesque, 1820) | |
Megalonaias nervosa, the Washboard is a freshwater mussel species in the family Unionidae.
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.
Megalonaias nervosa mussels are sexually mature around 8 years of age, they are late tachytictic breeders. From July to October the males are mature, while they female contain eggs from August through October (Hollandbartels, L. 1993). Megalonaias nervosa males release sperm and the females collect the sperm through the incurrent siphon. The eggs are fertilized internally. Megalonaias nervosa has a parasitic larva stage called glochidia, the mussel uses a lure to attract fish and then releases the glochidia when the fish is close enough. The glochidia latch onto the gills or fins of the fish and remain there feeding of the blood of the fish until the glochidia reach the juvenile stage. Known host species for Megalonaias nervosa include longnose gar, largemouth bass, yellow perch, longear sunfish, bluegill, slender-head darter, and log perch (O'Dee, S. and Watters, T. 1998). Parent mussel provides no care once the glochidia are released. Megalonaias nervosa are filter feeders, waste is released through the excurrent siphon. They are sedentary creatures and are anchored to the substrate or buried in the substrate. Studies had shown water temperature plays a role in reproduction, if the water temperature is too low, the mussels will not reproduce.
Megalonaias nervosa can be found in small or larger rivers and in a variety of substrate including mud, sand, or gravel. Although Megalonaias nervosa is of least conservation concern, mussels have suffered from habitat loss caused by pollution, invasive species and impoundment of water. Megalonaias nervosa reproduction rate has decreased in some areas due to low water temperature (Heinricher, J. and Layzer, J. 1999).
Megalonaias nervosa can be found in the Mississippi drainage, in the Gulf drainage from Ochlockonee River system west of the Rio Grande, and extends into northeastern Mexico. Does not occur in Canada. [1]
Megalonaias nervosa is similar to Threeridge (Amblema plicata) and Rock pocketbook (Arcidens confragosus).
The dwarf wedgemussel is an endangered species of freshwater mussel, an aquatic bivalve mollusk in the family Unionidae, the river mussels.
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.
Unio crassus, the thick shelled river mussel, is a species of freshwater mussel, an aquatic bivalve mollusk in the family Unionidae, the river mussels.
Alasmidonta atropurpurea, common name Cumberland elktoe, is a species of freshwater mussel, an aquatic bivalve mollusk in the family Unionidae, the river mussels.
Unionida is a monophyletic order of freshwater mussels, aquatic bivalve molluscs. The order includes most of the larger freshwater mussels, including the freshwater pearl mussels. The most common families are the Unionidae and the Margaritiferidae. All have in common a larval stage that is temporarily parasitic on fish, nacreous shells, high in organic matter, that may crack upon drying out, and siphons too short to permit the animal to live deeply buried in sediment.
The elktoe is a species of freshwater mussel, an aquatic bivalve mollusk in the family Unionidae, the river mussels. This species is found in southeastern Canada and the eastern United States. Like many mussels, it is threatened by water pollution from agriculture, industry, and other development, such as acid mine drainage and sedimentation. It may be extinct in Oklahoma.
The Appalachian elktoe is a species of freshwater mussel in the family Unionidae, the river mussels. It is native to the United States, where it is known only from North Carolina and Tennessee.
Lampsilis abrupta, the pink mucket or pink mucket pearly mussel, is a species of freshwater mussel, an aquatic bivalve mollusk in the family Unionidae, the river mussels. This species is endemic to the United States.
Hamiota altilis, the finelined pocketbook, is a species of freshwater mussel, an aquatic bivalve mollusk in the family Unionidae, the river mussels.
Lampsilis higginsii is a rare species of freshwater mussel known as Higgins' eye pearly mussel or simply Higgins' eye. It is endemic to the United States, where it occurs in the upper Mississippi River and the drainages of some of its tributaries. It is threatened by the introduced zebra mussel. Lampsilis higginsii is a federally listed endangered species.
Hamiota perovalis, the orangenacre mucket or orange-nacre mucket, is a species of freshwater mussel, an aquatic bivalve mollusk in the family Unionidae, the river mussels.
Lampsilis powellii is a rare species of freshwater mussel known by the common name Arkansas fatmucket. It is endemic to Arkansas in the United States, where it occurs in the Ouachita, Saline, and Caddo River systems. It is one of two mussels endemic to Arksansas, the other being speckled pocketbook. It is a federally listed threatened species of the United States.
Potamilus leptodon, the scaleshell mussel or scale shell, is a species of freshwater mussel in the family Unionidae, the river mussels. This aquatic bivalve mollusk has disappeared from much of its historical range. It is endemic to the United States, where it is now present in four or fewer states; it is only found with any regularity in Missouri. It is a federally listed endangered species of the United States.
Paetulunio fabalis, the rayed bean, is a species of freshwater mussel, an aquatic bivalve mollusk in the family Unionidae, the river mussels. It is the only species in the genus Paetulunio, and was formerly classified in Villosa until a 2018 study.
The shinyrayed pocketbook is an endangered species of freshwater mussel in the family Unionidae, the river mussels. This species is endemic to the United States in the states of Georgia, Florida, and Alabama.
Obovaria arkansasensis, the Southern Hickorynut, is a species of freshwater mussel, an aquatic bivalve mollusc in the family Unionidae, the river mussels. It lives in the southern United States, and has a complex life history including its larvae being parasitic on a fish host.
Fusconaia flava, the Wabash pigtoe, is a freshwater mussel in the family Unionidae. This species occurs in southern Manitoba and Ontario, Canada as well as in the eastern and midwestern United States from North Dakota to New York, south to Mississippi and Texas.
Sinanodonta beringiana, the Yukon floater, is a freshwater mussel, an aquatic bivalve mollusk in the family Unionidae, the river mussels.
Lampsilis radiata, also known as the eastern lampmussel, is a species of freshwater mussel in the family Unionidae. It is native to the north Atlantic coast of North America.
Hamiota australis, the southern sandshell, is a species of freshwater mussel, an aquatic bivalve mollusc in the family Unionidae, the river mussels.
