Estuary perch
Encyclopedia
The estuary perch, Macquaria colonorum, is an Australia
n species of the Percichthyidae family.
It is very similar to and very closely related to its sister species the Australian bass
, Macquaria novemaculeata. Key differences in estuary perch are that:
Estuary perch breed in winter at the same time as Australian bass, and the sexual dimorphism
possessed by Australian bass and other Macquaria species — of much larger females than males — seems to be present in estuary perch as well. Out of interest, occasionally estuary perch/Australian bass hybrids are recovered; they are presumed to be non-viable.
Female estuary perch reach sexual maturity at older, larger sizes than males.
Estuary perch continue the trend of native fish of southeast Australia being incredibly long-lived. Longevity is a survival strategy to ensure that most adults participate in at least one exceptional spawning and recruitment event, which are often linked to unusually wet La Niña
years and may only every one or two decades. Maximum recorded age is 36 years.
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
n species of the Percichthyidae family.
It is very similar to and very closely related to its sister species the Australian bass
Australian bass
Australian bass are a small to medium sized, primarily freshwater native fish found in coastal rivers and streams along the east coast of Australia. They are a member of the Percichthyidae family and, currently, the Macquaria genus. Australian bass are an iconic, highly predatory native fish...
, Macquaria novemaculeata. Key differences in estuary perch are that:
- it has a slightly larger mouth and slightly more "scooped" forehead;
- it tends to remain in the estuarine reaches or (more rarely) the extreme lower freshwater reaches;
- it has a diet with more emphasis on small fish and prawns;
- it has a slightly larger growth potential than Australian Bass.
Estuary perch breed in winter at the same time as Australian bass, and the sexual dimorphism
Sexual dimorphism
Sexual dimorphism is a phenotypic difference between males and females of the same species. Examples of such differences include differences in morphology, ornamentation, and behavior.-Examples:-Ornamentation / coloration:...
possessed by Australian bass and other Macquaria species — of much larger females than males — seems to be present in estuary perch as well. Out of interest, occasionally estuary perch/Australian bass hybrids are recovered; they are presumed to be non-viable.
Female estuary perch reach sexual maturity at older, larger sizes than males.
Estuary perch continue the trend of native fish of southeast Australia being incredibly long-lived. Longevity is a survival strategy to ensure that most adults participate in at least one exceptional spawning and recruitment event, which are often linked to unusually wet La Niña
La Niña
La Niña is a coupled ocean-atmosphere phenomenon that is the counterpart of El Niño as part of the broader El Niño-Southern Oscillation climate pattern. During a period of La Niña, the sea surface temperature across the equatorial Eastern Central Pacific Ocean will be lower than normal by 3–5 °C...
years and may only every one or two decades. Maximum recorded age is 36 years.