''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. Although the term specifically excludes seawater and brackish water, it does include ...

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 ...

in the family Atyidae. It is endemic to New Zealand, where it is distributed from

North Island The North Island, also officially named Te Ika-a-Māui, is one of the two main islands of New Zealand, separated from the larger but much less populous South Island by the Cook Strait. The island's area is , making it the world's 14th-largest ...

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

, and including the Chatham Islands. 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 chelipeds, 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 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. In arthropods, an appendage refers to any of the homologous body parts that may extend from a body segment, including ant ...

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 decapod ( crustaceans such as a crab, lobster, shrimp or prawn) is made up of 20 body segments grouped into two main body parts: the cephalothorax and the pleon (abdomen). Each segment may possess one pair of appendages, although in various ...

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, plur ...

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 planktonic, 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