The western pygmy perch (''Nannoperca vittata'') is a species of

temperate perch Percichthyidae, the temperate perches, are a family of freshwater ray-finned fish found in Australia and southern South America. Formerly placed in the order Perciformes, they are now placed in the order Centrarchiformes. The name Percichthyida ...

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 ...

southwestern Australia Southwest Australia is a biogeographic region in Western Australia. It includes the Mediterranean-climate area of southwestern Australia, which is home to a diverse and distinctive flora and fauna. The region is also known as the Southwest Au ...

Description

The Western pygmy perch is a small fish with an olive, brown and green mottled body with tow orange stripes along the flanks. In the breeding season the males develop brighter colouration with golden mottling along the flanks, a reddish-orange abdomen and the fins darken. The females develop a bluish colour when breeding. It can reach TL.

Distribution

The Western pygmy perch is endemic to the south-western coastal drainages of

Western Australia Western Australia (WA) is the westernmost state of Australia. It is bounded by the Indian Ocean to the north and west, the Southern Ocean to the south, the Northern Territory to the north-east, and South Australia to the south-east. Western Aust ...

. Its range extends from the Waychinicup River east of Albany to the

Arrowsmith River The Arrowsmith River lies within the Mid West region of Western Australia. The explorer George Grey found the river on 11 April 1839, on his second expedition along the west coast. He named it after the distinguished English cartographer John ...

north of

Perth Perth () is the list of Australian capital cities, capital city of Western Australia. It is the list of cities in Australia by population, fourth-most-populous city in Australia, with a population of over 2.3 million within Greater Perth . The ...

. It occurs in the majority of the river drainages within its range, as well as in lakes near the south coast.

Habitat and biology

The Western pygmy perch is found predominantly in lakes, streams, and swamps, and can withstand a degree of brackishness. They have a preference for living among vegetation in the shallows around the water perimeter, and acclimatise readily to a range of water temperatures from almost 0 to 25 °C. Pygmy perch are egg layers. They produce eggs singly, laying 12 to 15 over a period of up to three hours. During the breeding season (July to November), both sexes become noticeably more colorful. The eggs measure around 1.2 mm and are slightly adhesive, which allows them to cling to submerged plants, rocks, or debris. Spawning usually occurs in the latter part of the morning. Hatching occurs after around three days from laying. The 3-mm larvae look quite different from juveniles of the species and have no mouth for several days, but are recognizably perch-like after around 27 to 30 days. This species is mainly carnivorous, they eat various

diptera Flies are insects of the order Diptera, the name being derived from the Greek δι- ''di-'' "two", and πτερόν ''pteron'' "wing". Insects of this order use only a single pair of wings to fly, the hindwings having evolved into advance ...

n larvae, including mosquitos,

ostracods Ostracods, or ostracodes, are a class of the Crustacea (class Ostracoda), sometimes known as seed shrimp. Some 33,000 species (only 13,000 of which are extant) have been identified,Brandão, S.N.; Antonietto, L.S; Nery, D.G.; Santos, S.G.; Karano ...

, and

copepods Copepods (; meaning 'oar-feet') are a group of small crustaceans found in nearly every freshwater and saltwater habitat. Some species are planktonic (living in the water column), some are benthic (living on the sediments), several species have ...

, and small quantities of

algae Algae ( , ; : alga ) is an informal term for any organisms of a large and diverse group of photosynthesis, photosynthetic organisms that are not plants, and includes species from multiple distinct clades. Such organisms range from unicellular ...

, and are adept at taking mosquitoes from the surface of the water. They attain sexual maturity at one year old, and can live as long as 5 years.

Uses

Pygmy perch may be safely kept in an aquarium along with tropical fish. They are considered safe with tadpoles, so are used in frog ponds to control mosquito larvae.

References

{{Taxonbar, from=Q6431678

western pygmy perch The western pygmy perch (''Nannoperca vittata'') is a species of temperate perch endemic to southwestern Australia. Description The Western pygmy perch is a small fish with an olive, brown and green mottled body with tow orange stripes along th ...

Freshwater fish of Western Australia

Taxa named by François-Louis Laporte, comte de Castelnau Endemic fauna of Southwest Australia