Geographic Range
Macquaria australasica
is only found in Australia. (Paxton et. al., 1989). In it's native range, this species
occurs in highest abundance in the Murray-Darling basin in New South Wales.
Macquaria australasica
was introduced in the Wannon, Barwon, and Yarra Rivers in Victoria, Australia, as
well as the Nepean and Shoalhaven Rivers, in New South Wales. Within these areas,
there are three different population areas that this species inhabits including; west
of the Great Dividing Range, the Hawkesbury River, and the lower Shoalhaven River.
Some populations are the result of translocations, although few, healthy translocated
populations remain.
Two, genetically distinct groups of Macquarie perch have been described from coastal
and inland areas. Although it is likely that they represent different species, those
species have not been described yet.
- Biogeographic Regions
- australian
Habitat
This freshwater species lives in rivers and stream, preferring deep, rocky pools.
(Reide, 2004). They also favor cool and clear water with slow-moving riffles or shallow
running water.
Macquaria australasica
spawn in lakes and above holes in faster moving riffles at depths of 0 to 4 meters.
(DEH, 2005).
- Habitat Regions
- temperate
- freshwater
- Aquatic Biomes
- lakes and ponds
- rivers and streams
Physical Description
This species is a moderate-sized fish that is usually 25 to 40 cm in length and weighs
about 1.5 kg. The coloration of
Macquaria australasica
varies from a dark silvery/purplish grey which looks almost black to a bluish grey
or green-brown color with a ventral side that includes shades of pale white or tan
with a yellow tinge on some. The fish has an elongated, deep, and laterally compressed
body. Their caudal, anal and spiny dorsal fins are usually rounded. The fish have
small mouths and white eyes and the irises are silver. Adult species have a humped
back and also possess a rounded tail.
- Other Physical Features
- ectothermic
- heterothermic
- bilateral symmetry
- Sexual Dimorphism
- female larger
Development
The eggs of
M. australasica
are transparent and increase in size to a diameter of 4.0 mm. Once released, they
are swept downstream and lodge in pebbles. The eggs usually hatch in 10 to 18 days
in temperatures of 11 to 18°C. (Allen, 1989). The larvae then shelter in boulders
and pebbles. Females grow much faster than males and are always bigger than males.
The fish grow rapidly and their size is determined by the conditions of the water
they live in. Age determines onset of gonadal maturation. For females, spawning begins
at four years old and continues until the fish are ten years old. Female ovarian development
begins earlier in the year around February to April, pauses until August and then
rapidly resumes maturation to reach the gravid-gonad stage in late October or early
November. For males the development of the testes remains unchanged until August and
then a rapid maturation occurs that produces ripe males by October or early November
just like the females. Larvae and transitioning juveniles are usually deep bodied
with a laterally compressed head. The fish have 24 to 25 myomeres. The large gut in
the fish is fully coiled and the gas bladder is over the midgut and small in size
which makes it difficult to distinguish in transitioning juveniles. The large head
is elongated like the body with a concave snout that is approximately the same length
as the eye diameter. The eyes are small in larvae but become large in transitioning
juveniles as well as adults. Small canine teeth are observed in both jaws in all larvae
and adults.
Reproduction
Breeding fish migrate upstream and gather in schools which can last for several weeks.
Males nudge the female vent region which causes the release of eggs and then fertilization.
Females are oviparous and mate each year. (Merrick and Schmida, 1984).
- Mating System
- monogamous
Spawning occurs in shallow upland streams and the fish usually migrate in order to
spawn. Many fish use the same river to spawn each year. This occurs in fast-flowing
water over gravel beds and the eggs stick to the gravel on the bottom of the water
(demersal). (Merrick and Schmida, 1984). Females produce, on average, 32,000 eggs
per kg of fish.
Male M. australasica usually mature around the age of two years old and 21 cm in length while females do not reach maturity until they are three years old and 30 cm in length.
- Key Reproductive Features
- iteroparous
- seasonal breeding
- sexual
- fertilization
- broadcast (group) spawning
- oviparous
During spawning females remain close to the area where they laid their eggs in groups
of two or four. One or two males usually accompany the females during this time to
make sure that nothing happens to the eggs. After the eggs hatch the larvae travel
downstream either through swimming or from the current of the stream.
- Parental Investment
-
pre-fertilization
- provisioning
-
protecting
- female
-
pre-hatching/birth
-
protecting
- male
- female
-
protecting
Lifespan/Longevity
There has not been sufficient research on the lifespan of
M. australasica
, but average lifespan has been reported at 20 years with a maximum recorded age of
26 years.
Behavior
Macquarie perch are schooling fish. They make small, seasonal migrations upstream
to spawning sites.
- Key Behaviors
- natatorial
- diurnal
- motile
- migratory
- social
Communication and Perception
Research for how this species communicates and perceives its environment is insufficient.
Like most fish, they probably use chemical and visual input as important modes of
perceiving and communicating.
Food Habits
The bulk of their diet consists of aquatic invertebrates such as caddisfly, stonefly
and mayfly species, with a small quantity of terrestrial insects taken as well. Adults
feed at the bottom of lakes and rivers. Young are zooplanktivores, and eat water fleas,
rotifers and water mites by sucking them up into their mouths. (Merrick and Schimda,
1984).
- Primary Diet
- carnivore
- Animal Foods
- insects
- mollusks
- aquatic or marine worms
- aquatic crustaceans
- zooplankton
Predation
Predators on
M. australasica
include Australian bass (
Macquaria novemaculeata
) and the introduced species: rainbow trout (
Oncorhynchus mykiss
) and redfin (
Perca fluviatilis
).
Ecosystem Roles
Macquarie perch are important predators in natural ecosystems, and prey to larger
animals. The introduced fish species,
Salmo trutta
and
Oncorhynchus mykiss
, may compete with Macquarie perch for food.
Economic Importance for Humans: Positive
Macquarie perch have been and are still fished for food. They are important members
of native Australian freshwater ecosystems.
- Positive Impacts
- food
Economic Importance for Humans: Negative
When this species is relocated to other ranges or even within its home range, diseases
from other fish are sometimes spread as well, affecting other fish species and other
populations of Macquarie perch.
- Negative Impacts
- injures humans
Conservation Status
Macquarie perch are considered endangered in Australia, but this is not yet reflected
in international conservation organizations.
Macquaria australasica
is threatened by predation and competition from exotic fish species, including redfin
(
Perca fluviatilis
), rainbow trout (
Oncorhynchus mykiss
), and brown trout (
Salmo trutta
). They are also threatened by dams, habitat destruction, sedimentation, heavy metal
pollution, and introduced diseases. Dam removal is recommended for species recovery
so that migration to spawning sites can occur. Illegal fishing occurs in some areas
and overfishing is considered one of the contributing factors to the rarity of this
species.
Other Comments
M. australasica
is in the Family
Percichthyidae
. Common names include: Macquarie perch, Macquarie-aborre, Macquaries barsch, mountain
perch, black bream, silberauge, silvereye, and white-eye.
Additional Links
Contributors
Leah Kosakowski (author), University of Michigan-Ann Arbor, Kevin Wehrly (editor, instructor), University of Michigan-Ann Arbor.
- Australian
-
Living in Australia, New Zealand, Tasmania, New Guinea and associated islands.
- introduced
-
referring to animal species that have been transported to and established populations in regions outside of their natural range, usually through human action.
- native range
-
the area in which the animal is naturally found, the region in which it is endemic.
- temperate
-
that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).
- freshwater
-
mainly lives in water that is not salty.
- ectothermic
-
animals which must use heat acquired from the environment and behavioral adaptations to regulate body temperature
- heterothermic
-
having a body temperature that fluctuates with that of the immediate environment; having no mechanism or a poorly developed mechanism for regulating internal body temperature.
- bilateral symmetry
-
having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.
- monogamous
-
Having one mate at a time.
- iteroparous
-
offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).
- seasonal breeding
-
breeding is confined to a particular season
- sexual
-
reproduction that includes combining the genetic contribution of two individuals, a male and a female
- fertilization
-
union of egg and spermatozoan
- external fertilization
-
fertilization takes place outside the female's body
- oviparous
-
reproduction in which eggs are released by the female; development of offspring occurs outside the mother's body.
- natatorial
-
specialized for swimming
- diurnal
-
- active during the day, 2. lasting for one day.
- motile
-
having the capacity to move from one place to another.
- migratory
-
makes seasonal movements between breeding and wintering grounds
- social
-
associates with others of its species; forms social groups.
- visual
-
uses sight to communicate
- tactile
-
uses touch to communicate
- chemical
-
uses smells or other chemicals to communicate
- zooplankton
-
animal constituent of plankton; mainly small crustaceans and fish larvae. (Compare to phytoplankton.)
- food
-
A substance that provides both nutrients and energy to a living thing.
- causes disease in humans
-
an animal which directly causes disease in humans. For example, diseases caused by infection of filarial nematodes (elephantiasis and river blindness).
- carnivore
-
an animal that mainly eats meat
- insectivore
-
An animal that eats mainly insects or spiders.
References
ACT Government, 1999. "Macquarie Perch (Macquaria australasica): An Endangered Species" (On-line). Action Plan No. 13. Accessed October 08, 2005 at http://www.environment.act.gov.au/Files/actionplans13.pdf .
Allen, G. 1989. Freshwater fishes of Australia. . Neptune City, New Jersey: T.F.H. Publications, Inc.. Accessed October 08, 2005 at http://fishbase.org/References/SummaryRefList.cfm .
Department of the Environment and Heritage, 2005. "Macquaria australasica, Macquarie Perch" (On-line). Accessed October 07, 2005 at http://www.deh.gov.au/cgi-bin/sprat/public/publicspecies.pl?taxon_id=66632 .
Ingram, B., J. Douglas, M. Lintermans. 2000. Threatened Fishes of the World: Macquaria australasica, Cuvier 1830 (Percichthyidae). Environmental Biology of Fishes , 59: 68. Accessed October 09, 2005 at http://www.springerlink.com/media/e3d05mtqmg3ktxn7qu5m/contributions/h/6/3/2/h632wk7188x61340.pdf .
Merrick, J., G. Schmida. 1984. Australian freshwater fishes: biology and management . South Australia: Griffin Press Ltd. Accessed October 08, 2005 at http://fishbase.org/Ecology/FishEcologySummary.cfm?StockCode=10889&GenusName=Macquaria&SpeciesName=australasica .
Paxton, J., D. Hoese, G. Allen, J. Hanley. 1989. Pisces. Petromyzontidae to Carangidae. Zoological Catalogue of Australia , Vol. 7: 665. Accessed October 08, 2005 at http://fishbase.org/References/FBRefsummary.cfm?id=7300 .
Reide, K. 2004. Global register of migratory species - from global to regional scales. Final Report of the R&D-Projekt 808 05 081 . Bonn, Germany: Federal Agency for Nature Conservation. Accessed October 08, 2005 at http://fishbase.org/References/SummaryRefList.cfm?ID=10566&GenusName=Macquaria&SpeciesName=australasica .