Pedder galaxias
Encyclopedia
Pedder galaxias, Galaxias pedderensis, is a critically endangered
Australia
n freshwater fish. It is considered to be extinct in the wild and was originally found only in Lake Pedder
in Tasmania
.
and Wedge River. However, by 1980 it had become very rare and no new specimens have been captured in the wild since 1996. Introduced trout are implicated as a major factor in the decline of this species.
Diet consists of small invertebrate
s, particularly arthropod
s and aquatic insect larva
e, crustacean
s and terretrial insect
s especially beetle
s, flies
, cicada
s etc.
.
Critically endangered
Version 2010.3 of the IUCN Red List of Threatened Species identified 3744 Critically Endangered species, subspecies and varieties, stocks and subpopulations.Critically Endangered by kingdom:*1993 Animalia*2 Fungi*1745 Plantae*4 Protista-References:...
Australia
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 freshwater fish. It is considered to be extinct in the wild and was originally found only in Lake Pedder
Lake Pedder
Lake Pedder was once a natural lake, located in the southwest of Tasmania, Australia but the name is now used in an official sense to refer to the much larger artificial impoundment and diversion lake formed when the original lake was expanded by damming in 1972 by the Hydro Electric Commission of...
in Tasmania
Tasmania
Tasmania is an Australian island and state. It is south of the continent, separated by Bass Strait. The state includes the island of Tasmania—the 26th largest island in the world—and the surrounding islands. The state has a population of 507,626 , of whom almost half reside in the greater Hobart...
.
Range
Originally recorded only in Lake Pedder and inflowing streams, after the construction of the Huon-Serpentine dam in 1972 (the "new" Lake Pedder), its range expanded initially into Lake GordonLake Gordon
Lake Gordon is a reservoir created by the Gordon Dam on the upper reaches of the Gordon River in south-west Tasmania, Australia. The reservoir was formed in the early 1970s as a result of the dam construction by the HEC...
and Wedge River. However, by 1980 it had become very rare and no new specimens have been captured in the wild since 1996. Introduced trout are implicated as a major factor in the decline of this species.
Description
A small greenish-brown fish, off-white to silvery belly, a profuse irregular and highly variable pattern of alternating off-white and brownish contrasting bands extending into the base of the fins and breaking up into fine spots on the lowerr part of the sides. Length to 160 mm.Habitat
Before the construction of the new lake, this species preferred Lake Pedder itself which was quite shallow surrounded by white sandy beaches and small rooted aquatic vegetation as well as in swamps and low velocity waters with abundant instream organic debris and overhanging terrestrial vegetation.Diet consists of small invertebrate
Invertebrate
An invertebrate is an animal without a backbone. The group includes 97% of all animal species – all animals except those in the chordate subphylum Vertebrata .Invertebrates form a paraphyletic group...
s, particularly arthropod
Arthropod
An arthropod is an invertebrate animal having an exoskeleton , a segmented body, and jointed appendages. Arthropods are members of the phylum Arthropoda , and include the insects, arachnids, crustaceans, and others...
s and aquatic insect larva
Larva
A larva is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle...
e, crustacean
Crustacean
Crustaceans form a very large group of arthropods, usually treated as a subphylum, which includes such familiar animals as crabs, lobsters, crayfish, shrimp, krill and barnacles. The 50,000 described species range in size from Stygotantulus stocki at , to the Japanese spider crab with a leg span...
s and terretrial insect
Insect
Insects are a class of living creatures within the arthropods that have a chitinous exoskeleton, a three-part body , three pairs of jointed legs, compound eyes, and two antennae...
s especially beetle
Beetle
Coleoptera is an order of insects commonly called beetles. The word "coleoptera" is from the Greek , koleos, "sheath"; and , pteron, "wing", thus "sheathed wing". Coleoptera contains more species than any other order, constituting almost 25% of all known life-forms...
s, flies
Fly
True flies are insects of the order Diptera . They possess a pair of wings on the mesothorax and a pair of halteres, derived from the hind wings, on the metathorax...
, cicada
Cicada
A cicada is an insect of the order Hemiptera, suborder Auchenorrhyncha , in the superfamily Cicadoidea, with large eyes wide apart on the head and usually transparent, well-veined wings. There are about 2,500 species of cicada around the world, and many of them remain unclassified...
s etc.
Conservation status
- Critically endangered on IUCN Red ListIUCN Red ListThe IUCN Red List of Threatened Species , founded in 1963, is the world's most comprehensive inventory of the global conservation status of biological species. The International Union for Conservation of Nature is the world's main authority on the conservation status of species...
(last assessed in 1996). - Extinct in the wild status for the EPBC Act since 2005.
Reproduction
Females are larger than males. Male genital papilla narrow, whereas female are broad and rounded, most noticeable during breeding season. 150 to 1,200 eggs averaging 1.9 mm to 2.3 mm in diameter when water hardened. Spawning reported to occur in spring (October) at water temperatures of 6.7 to 7.5°CCelsius
Celsius is a scale and unit of measurement for temperature. It is named after the Swedish astronomer Anders Celsius , who developed a similar temperature scale two years before his death...
.