''Macrobrachium ohione'', commonly known as the Ohio shrimp, Ohio river shrimp or Ohio river prawn, is a species of

freshwater Fresh water or freshwater is any naturally occurring liquid or frozen water containing low concentrations of dissolved salts and other total dissolved solids. Although the term specifically excludes seawater and brackish water, it does in ...

shrimp Shrimp are crustaceans (a form of shellfish) with elongated bodies and a primarily swimming mode of locomotion – most commonly Caridea and Dendrobranchiata of the decapod order, although some crustaceans outside of this order are refer ...

found in rivers throughout the

Gulf of Mexico The Gulf of Mexico ( es, Golfo de México) is an ocean basin and a marginal sea of the Atlantic Ocean, largely surrounded by the North American continent. It is bounded on the northeast, north and northwest by the Gulf Coast of the United S ...

and

Atlantic Ocean The Atlantic Ocean is the second-largest of the world's five oceans, with an area of about . It covers approximately 20% of Earth#Surface, Earth's surface and about 29% of its water surface area. It is known to separate the "Old World" of Afr ...

drainage basin A drainage basin is an area of land where all flowing surface water converges to a single point, such as a river mouth, or flows into another body of water, such as a lake or ocean. A basin is separated from adjacent basins by a perimeter, ...

s of North America. It is the best-known of all North American freshwater shrimp, and is commonly used as

bait Bait may refer to: General * Bait (luring substance), bait as a luring substance ** Fishing bait, bait used for fishing Film * ''Bait'' (1950 film), a British crime film by Frank Richardson * ''Bait'' (1954 film), an American noir film by Hu ...

for commercial fishing, especially

catfish Catfish (or catfishes; order Siluriformes or Nematognathi) are a diverse group of ray-finned fish. Named for their prominent barbels, which resemble a cat's whiskers, catfish range in size and behavior from the three largest species alive, ...

Description

''Macrobrachium ohione'' is pale gray with small blue spots and grows up to long. Its first two pairs of legs are

claw A claw is a curved, pointed appendage found at the end of a toe or finger in most amniotes (mammals, reptiles, birds). Some invertebrates such as beetles and spiders have somewhat similar fine, hooked structures at the end of the leg or tars ...

ed, with the second pair larger than the first. The rostrum is curved and contains up to 13 teeth.

Distribution

The species may be found from

North Carolina North Carolina () is a state in the Southeastern region of the United States. The state is the 28th largest and 9th-most populous of the United States. It is bordered by Virginia to the north, the Atlantic Ocean to the east, Georgia a ...

Florida Florida is a state located in the Southeastern region of the United States. Florida is bordered to the west by the Gulf of Mexico, to the northwest by Alabama, to the north by Georgia, to the east by the Bahamas and Atlantic Ocean, a ...

on the Atlantic coast of North America, and from the southern tip of

Missouri Missouri is a U.S. state, state in the Midwestern United States, Midwestern region of the United States. Ranking List of U.S. states and territories by area, 21st in land area, it is bordered by eight states (tied for the most with Tennessee ...

Louisiana Louisiana , group=pronunciation (French: ''La Louisiane'') is a U.S. state, state in the Deep South and South Central United States, South Central regions of the United States. It is the List of U.S. states and territories by area, 20th-smal ...

further westward. Despite the common name, the Ohio shrimp is not generally found in the Ohio River anymore. Until the 1930s, it was common in the Ohio River, with the

type specimen In biology, a type is a particular specimen (or in some cases a group of specimens) of an organism to which the scientific name of that organism is formally attached. In other words, a type is an example that serves to anchor or centralizes the ...

having been taken at

Cannelton, Indiana Cannelton is a city in Troy Township, Perry County, in the U.S. state of Indiana, along the Ohio River. The population was 1,563 at the 2010 census. Cannelton, which was the smallest incorporated city in the state until 2010, was formerly the co ...

, and its range in the

Mississippi River The Mississippi River is the second-longest river and chief river of the second-largest drainage system in North America, second only to the Hudson Bay drainage system. From its traditional source of Lake Itasca in northern Minnesota, it ...

extended as far north as

St. Louis, Missouri St. Louis () is the second-largest city in Missouri, United States. It sits near the confluence of the Mississippi and the Missouri Rivers. In 2020, the city proper had a population of 301,578, while the bi-state metropolitan area, whic ...

Dam A dam is a barrier that stops or restricts the flow of surface water or underground streams. Reservoirs created by dams not only suppress floods but also provide water for activities such as irrigation, human consumption, industrial use, a ...

interbasin transfer Interbasin transfer or transbasin diversion are (often hyphenated) terms used to describe man-made conveyance schemes which move water from one river basin where it is available, to another basin where water is less available or could be utilized ...

of water, and other human activities are thought to be the cause for the decrease in range. In May 2001, two specimens were found in the Ohio River in

Joppa, Illinois Joppa is a village in Massac County, Illinois, United States, along the Ohio River. The population was 350 as of the 2020 census. It is part of the Paducah, KY-IL Micropolitan Statistical Area. History During the first part of the 19th centu ...

, the first ones in 50 years, indicating either that the species is returning to its former range, or that prior sampling methods were ineffective.

Reproduction

Like other ''Macrobrachium'' species, the Ohio shrimp is

amphidromous Fish migration is mass relocation by fish from one area or body of water to another. Many types of fish migrate on a regular basis, on time scales ranging from daily to annually or longer, and over distances ranging from a few metres to thousan ...

. The

larva A larva (; plural larvae ) is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle. Th ...

e must live in saltwater and move to fresh water as adults. This is accomplished by having the larvae drift, free-floating, down the river until they reach water where the

salinity Salinity () is the saltiness or amount of salt dissolved in a body of water, called saline water (see also soil salinity). It is usually measured in g/L or g/kg (grams of salt per liter/kilogram of water; the latter is dimensionless and equal ...

is high enough to support them. Females carrying eggs may also migrate downstream before releasing the larvae to reduce the time required for travel. A 2008 study by the

University of Louisiana at Lafayette The University of Louisiana at Lafayette (UL Lafayette, University of Louisiana, ULL, or UL) is a public research university in Lafayette, Louisiana. It has the largest enrollment within the nine-campus University of Louisiana System and the s ...

discovered that ''M. ohione'' larvae are viable for up to five days in fresh water. After this, the likelihood of their

molting In biology, moulting (British English), or molting (American English), also known as sloughing, shedding, or in many invertebrates, ecdysis, is the manner in which an animal routinely casts off a part of its body (often, but not always, an outer ...

and surviving in saltwater is drastically diminished. The researchers concluded that dams and other human-erected barriers, by blocking the larval drift, are likely to be the primary reason that Ohio River shrimp are almost non-existent in the Ohio River.

References

{{Taxonbar, from=Q3027391 Palaemonidae Freshwater crustaceans of North America Fauna of the Plains-Midwest (United States) Crustaceans described in 1874 Taxa named by Sidney Irving Smith