The Ouachita River is a 605-mile-long (974 km) river that runs south and east through the U.S. states of Arkansas and Louisiana, joining the Tensas River to form the Black River near Jonesville, Louisiana. It is the 25th-longest river in the United States.
The leopard darter is a species of freshwater ray-finned fish, a darter from the subfamily Etheostomatinae, part of the family Percidae, which also contains the perches, ruffes and pikeperches. It is native to the United States, where it can be found only in the Little River drainage in Oklahoma and Arkansas. Its typical habitat is medium to large streams with rubble and boulder substrate. It feeds on small invertebrates on the riverbed and spawns mainly in March and April. It is threatened by impoundment, habitat loss and runoff from agricultural activities. It has never been a common species and has been listed as a threatened species in the United States since 1978, and the International Union for Conservation of Nature lists it as a "vulnerable species".
The Ouachita madtom is a catfish of the family Ictaluridae. The first specimens of the species were collected in 1952 it was not until 1969 that they were recognised as a species. The Ouachita madtom is similar to the tadpole madtom except the Ouachita madtom has one internasal pore while the tadpole madtom has two, and 16 to 18 anal rays while the tadpole madtom has only 14 to 16. It is also similar to the slender madtom but differing in the lack of serrae on the pectoral spine, having more caudal rays, and usually eight pectoral rays while the slender madtom has 9. The maximum length of an Ouachita madtom is about 4 inches (10 cm).
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 Lost River sucker is a species of ray-finned fish in the family Catostomidae. It is the only living member of the genus Deltistes. It is found only in California and Oregon. Its population is much reduced from historical numbers for a number of reasons. It is federally listed as an endangered species of the United States. This species is known as the C'waam by the local Native American Nation, the Klamath Tribes.
The sharpnose shiner is a species of ray-finned fish in the family Cyprinidae, the carps and minnows. It is endemic to Texas in the United States, where it is limited to the upper Brazos River basin. In 2013 it became a candidate for federal listing as an endangered species of the United States.
The Caddo madtom is a species of fish in the family Ictaluridae endemic to the United States. N. taylori was named in honor of William Ralph Taylor, U.S. National Museum, in recognition of his contributions to the knowledge of catfishes. They average 2 to 4 inches long and weigh no more than a few ounces. N. taylori has a small to tiny, fragmented range, but is mostly found in the Caddo, Ouachita, and Little Missouri Rivers in southwestern Arkansas. Ecological studies indicate that dam and bridge construction poses barriers to dispersal and migration of fish in the Ouachita Highlands. IUCNredlist.org states that better information is needed on life history, reproductive biology, and ecology of the Caddo madtom. This species is listed as endangered on the IUCN Red List. Limited range makes this species vulnerable to habitat destruction/degradation from impoundment, pollution, and other factors. Robison and Buchanan (1988) stated, "this rare species should be considered threatened due to loss of habitat". Warren et al. (2000) categorized the species as "threatened".
Cumberlandia monodonta is a freshwater mussel endemic to the United States. Currently, C. monodonta is listed as an endangered species by the U.S. Fish and Wildlife Service and the International Union for Conservation of Nature.
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.
Lampsilis is a genus of freshwater mussels, aquatic bivalve mollusks in the family Unionidae, the river mussels. There are over 100 species in the genus.
Lampsilis cardium is a species of freshwater mussel in the family Unionidae, the river mussels. It is known commonly as the plain pocketbook. It is widespread in eastern North America, where it is native to the Mississippi River and Great Lakes drainage systems.
Lampsilis dolabraeformis is a species of freshwater mussel in the family Unionidae, the river mussels. It is known commonly as the Altamaha pocketbook. It is endemic to Georgia in the United States, where it is known only from the Altamaha River system.
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. Lapsilis 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 rafinesqueana, the Neosho mucket or Neosho pearly mussel, is a species of North American freshwater mussel endemic to Arkansas, Oklahoma, Illinois, Missouri and Kansas.
Leptodea 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.
The Louisiana pearlshell, Margaritifera hembeli, is a rare species of bivalve mollusk in the family Margaritiferidae. This freshwater mussel is native to Louisiana in the United States, and was previously present also in Arkansas. It grows to a length of about 10 cm (4 in) and lives on the sand or gravel stream-bed in riffles and fast flowing stretches of small streams. Its life cycle involves a stage where it lives parasitically inside a fish. This mollusk is sensitive to increased sedimentation and cannot tolerate impoundments. Because of its limited range and its population decline, the International Union for Conservation of Nature has rated this mollusk as being "critically endangered".
The triangular kidneyshell is a species of freshwater mussel, in the family Unionidae, the river mussels. It is endemic to Alabama in the United States, where it is known from several rivers and streams in the Mobile River Basin. It is a federally listed endangered species of the United States.
Obovaria arkansasensis, the Ouachita creekshell, is a species of freshwater mussel, an aquatic bivalve mollusc in the family Unionidae, the river mussels. It is endemic to certain rivers and streams in the Ouachita Mountains, Arkansas, and has a complex life history including its larvae being parasitic on a fish host.
Megalonaias nervosa is a freshwater mussel species in the family Unionidae. Washboard is the common name used for Megalonaias nervosa.
