Macrobrachium carcinus

{{Short description|Species of crustacean}}

{{Use dmy dates|date=September 2022}}

{{Speciesbox

| image = Macrobrachium carcinus.jpg

| status = LC

| status_system = IUCN3.1

| status_ref = {{cite iucn |author=De Grave, S. |date=2013 |title=Macrobrachium carcinus |volume=2013 |page=e.T198003A2508328 |doi=10.2305/IUCN.UK.2013-1.RLTS.T198003A2508328.en |access-date=12 November 2021}}

| genus = Macrobrachium

| species = carcinus

| authority = (Linnaeus, 1758){{cite WoRMS |author=Charles Fransen |year=2012 |title=Macrobrachium carcinus (Linnaeus, 1758) |id=246169 |access-date=1 June 2012}}

| synonyms =

• Cancer (Astacus) jamaicensis Herbst, 1792
• Cancer carcinus Linnaeus, 1758
• Palaemon aztecus de Saussure, 1857
• Palaemon brachydactylus Wiegmann, 1836
• Palaemon carcinus (Linnaeus, 1758)
• Palaemon laminatus von Martens, 1869
• Palaemon montezumae de Saussure, 1857
• Palaemon ornatus Torralbas, 1917
• Palemon brevicarpus De Haan, 1849
• Palemon punctatus Randall, 1840
• Periclimenes portoricensis Schmitt, 1933

| synonyms_ref =

}}

Macrobrachium carcinus is a species of fresh water shrimp known as the big claw river shrimp. It is native to streams, rivers and creeks from Florida to southern Brazil.{{cite encyclopedia|url=http://eol.org/pages/128503/details#distribution|title=Macrobrachium carcinus Bigclaw River Shrimp|encyclopedia=Encyclopedia of Life|access-date=1 June 2012}} It is the largest known species of Neotropical freshwater shrimp, growing up to {{convert|30|cm}} long and weighing as much as {{convert|850|g}},{{cite book |editor1=Michael Bernard New |editor2=Wagner Cotroni Valenti |editor3=James H. Tidwell |editor4=Louis R. D'Abramo |editor5=Methil Narayanan Kutty |title=Freshwater Prawns: Biology and Farming |chapter=Culture of other freshwater prawn species |author1=Methil Narayanan Kutty |author2=Wagner C. Valenti |name-list-style=amp |chapter-url=https://books.google.com/books?id=z-7Xjy2ANvQC&pg=PA511 |year=2009 |publisher=John Wiley & Sons|isbn=978-1-4051-4861-0|pages=502–523}} although even larger specimens have been reported.{{cite journal|title=Field & Stream|journal = Field & Stream 2007-08|url=https://books.google.com/books?id=-IXx9y49niUC&pg=PA78|access-date=1 June 2012|date=June 1998|page=78|issn=8755-8599}} It is an important species for commercial fishing in the Sao Francisco River basin, where it is known by the local name of pitu.{{cite book|author=Joachim Carolsfeld|title=Migratory Fishes of South America: Biology, Fisheries and Conservation Status|url=https://books.google.com/books?id=hjhpuDz5K_0C&pg=PA218|access-date=1 June 2012|date=1 November 2003|publisher=IDRC|isbn=978-0-9683958-2-0|page=218}} M. carcinus is omnivorous, with a diet consisting of molluscs, small fish, algae, leaf litter and insects.{{cite book|author=Douglas P. Reagan|title=The Food Web of a Tropical Rain Forest|url=https://books.google.com/books?id=uegRxo5t18YC&pg=PA452|access-date=1 June 2012|date=1 September 1996|publisher=University of Chicago Press|isbn=978-0-226-70599-6|page=452}}

Macrobrachium carcinus has a tan or yellow body with dark brown stripes. Its chelae are unusually long and thin, to facilitate foraging for food in small crevices, and may be blue or green in color.{{cite book|author=Jerry G. Walls|title=Crawfishes of Louisiana|url=https://books.google.com/books?id=JAG2Aut6yKcC&pg=PA220|access-date=1 June 2012|date=1 April 2009|publisher=LSU Press|isbn=978-0-8071-3409-2|page=220}}