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Macquarie perch

(Macquaria australasica)

galery

Description

The Macquarie perch (Macquaria australasica) is an Australian native freshwater fish of the Murray-Darling river system. It is a member of the family Percichthyidae and is closely related to the golden perch (Macquaria ambigua). The Macquarie perch derives its scientific name from the Macquarie River where the first scientifically described specimen was collected (Macquaria) and a derivation of the Latin word for "southern" (australasica). Macquarie perch are a medium-sized fish, commonly 30-40 cm and 1.0-1.5 kg. Maximum size is about 2.5 kg and 50 cm. Their body is elongated, deep, and laterally compressed. The caudal fin, anal fin and soft dorsal fin are rounded. Spiny dorsal fin medium height and strong. Mouth and eyes are relatively small. Colouration can vary from tan to (more commonly) dark purplish-grey to black. The irises of the eyes are distinctly silver. Macquarie perch are a relatively placid native fish species with the bulk of their diet consisting of aquatic invertebrates such as caddisfly, stonefly and mayfly species, with a small quantity of terrestrial insects taken as well. The Macquarie perch is primarily an upland native fish and has a breeding biology clearly adapted to flowing upland rivers and streams. (For this reason, the species has proven difficult to breed artificially, as captive females do not produce ripe eggs when kept in still broodponds or tanks). Macquarie perch breed in late spring at temperatures of 15 to 16 °C, in flowing water over unsilted cobble and gravel substrate. The demersal (sinking) eggs fall into the interstices (spaces) between the gravel and cobble, where they lodge and are then protected and incubated until hatching. This is a breeding strategy similar to that used by introduced species of trout. Macquarie perch appear to have inherited the sexual dimorphism of other Macquaria species where females reach a larger maximum size than males. Females also reach sexual maturity at older, larger sizes than males. Limited ageing work on Macquarie perch has recorded fish to 20 years of age. Maximum age for Macquarie perch is probably similar to the maximum age recorded for the closely related golden perch (26 years). Macquarie perch were originally found in the larger upland rivers and streams in the south-eastern corner of the Murray-Darling system, which they usually co-inhabited with trout cod and one or both of the blackfish species.

Taxonomic tree:

Domain:
Kingdom: Animalia
Phylum:
Class: Actinopterygii
Order:Perciformes
Family:Percichthyidae
Genus:Macquaria
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