''Paratya curvirostris'' 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. The term excludes seawater and brackish water, but it does include non-salty mi ...

shrimp A shrimp (: shrimp (American English, US) or shrimps (British English, UK)) is a crustacean with an elongated body and a primarily Aquatic locomotion, swimming mode of locomotion – typically Decapods belonging to the Caridea or Dendrobranchi ...

in the family

Atyidae Atyidae is a family of shrimp, present in all tropical and most temperate waters of the world. Adults of this family are almost always confined to fresh water Fresh water or freshwater is any naturally occurring liquid or frozen water conta ...

. It is

endemic Endemism is the state of a species being found only in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also foun ...

New Zealand New Zealand () is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and List of islands of New Zealand, over 600 smaller islands. It is the List of isla ...

, where it is distributed from

North Island The North Island ( , 'the fish of Māui', historically New Ulster) is one of the two main islands of New Zealand, islands of New Zealand, separated from the larger but less populous South Island by Cook Strait. With an area of , it is the List ...

Stewart Island Stewart Island (, ' glowing skies', officially Stewart Island / Rakiura, formerly New Leinster) is New Zealand's third-largest island, located south of the South Island, across Foveaux Strait. It is a roughly triangular island with a la ...

, and including the

Chatham Islands The Chatham Islands ( ; Moriori language, Moriori: , 'Misty Sun'; ) are an archipelago in the Pacific Ocean about east of New Zealand's South Island, administered as part of New Zealand, and consisting of about 10 islands within an approxima ...

. It is the only true decapod shrimp to inhabit freshwater in New Zealand.De Grave, S., Page, T. & Ayhong, S. 2013
''Paratya curvirostris''.
The IUCN Red List of Threatened Species 2013. Downloaded on 14 June 2016.

Description

''Paratya'' is distinguished from all other decapod shrimps by the specialized form of the first two pairs of

cheliped A chela ()also called a claw, nipper, or pinceris a pincer-shaped organ at the end of certain limbs of some arthropods. The name comes from Ancient Greek , through Neo-Latin '. The plural form is chelae. Legs bearing a chela are called chelipeds ...

s, which possess clusters of brushing setae or small hairs to pick up food. This shrimp feeds mainly by scraping detritus from the leaves of aquatic plants (''

Elodea ''Elodea'' is a genus of eight species of aquatic plants often called the waterweeds described as a genus in 1803. Classified in the frog's-bit family ( Hydrocharitaceae), ''Elodea'' is native to the Americas and is also widely used as aquarium v ...

spp.'' and milfoils), sometimes with all four chelipeds, bringing the organic material to the mouthparts where larger particles are shredded by the third pair of

maxilliped An appendage (or outgrowth) is an external body part or natural prolongation that protrudes from an organism's body such as an arm or a leg. Protrusions from single-celled bacteria and archaea are known as cell-surface appendages or surface app ...

s. It also eats small invertebrates such as midges. Adults grow up to 25mm in length. Sex can be identified by differences in the first two pairs of

pleopod The anatomy of a decapod consists of 20 body segments grouped into two main body parts: the cephalothorax and the pleon (abdomen). Each segment – often called a somite – may possess one pair of appendages, although in various groups these m ...

s, the male having larger

endopodite The arthropod leg is a form of jointed appendage of arthropods, usually used for walking. Many of the terms used for arthropod leg segments (called podomeres) are of Latin origin, and may be confused with terms for bones: ''coxa'' (meaning hip, : ...

s. The female carries up to 4000 eggs and once they are deposited, cleans them and provides water flow by beating her pleopods. Eggs took about 28 days to hatch in a laboratory experiment. Larvae are at first

plankton Plankton are the diverse collection of organisms that drift in Hydrosphere, water (or atmosphere, air) but are unable to actively propel themselves against ocean current, currents (or wind). The individual organisms constituting plankton are ca ...

ic, with fewer limbs and segments. From studies it has been suggested that first stage larvae migrate to the rivermouth to develop in saltwater, moving up the river or stream to less saline water in the later stages.Chapman, M. A., & Lewis, M. H., “An Introduction to the Freshwater Crustacea of New Zealand”, William Collins (NZ) Ltd, Auckland 1976,

Habitat

This species was common to abundant in a widespread range, but is now somewhat reduced with a patchy distribution, largely due to the introduction of trout to certain areas. It is rarely found above 40 meters in elevation.Carpenter, A. (1983)
Population biology of the freshwater shrimp ''Paratya curvirostris (Heller, 1862) (Decapoda: Atyidae).
''New Zealand rnal of Marine and Freshwater Research'' 17:2, 147-158.

References

External links

* {{Taxonbar, from=Q7136225 Atyidae Endemic fauna of New Zealand Freshwater crustaceans of New Zealand Crustaceans described in 1862 Endemic crustaceans of New Zealand Taxa named by Camill Heller