Western carp gudgeon

Taxobox
name = Western carp gudgeon
regnum = Animalia
phylum = Chordata
classis = Actinopterygii
ordo = Perciformes
familia = Eleotridae
genus = "Hypseleotris"
species = "H. klunzingeri"
binomial = "Hypseleotris klunzingeri"
binomial_authority = Ogilby, 1898

The western carp gudgeon, "Hypseleotris klunzingeri", is a carp gudgeon of the Eleotridae family. Carp gudgeons are small perciform fish (similar in size, shape and colour) found in the Australian Murray-Darling river system, mainly in lowland environments, but some have been observed in upland environments. They are often found in small creeks, as well as billabongs and the edges of larger rivers. They prefer water 1 to 2 m deep with aquatic weed and structure provided by rocks or sunken timber (usually the latter).

Like many other Murray-Darling native fish species, western carp gudgeon have crossed the Great Dividing Range through natural river capture events and are found in a number of East Coast drainages, from the Hunter River system in northern New South Wales to the Fitzroy River system in central Queensland.

Description

Western carp gudgeon are small fish, with a maximum size of approximately 6 cm. Usually their body is a yellowy-gold colour overlaid with subtle dark grey blotches, with semi-translucent fins. Males develop spectacular spawning colours in summer, namely a more metallic-bronze body colour with a red stripe through the caudal (tail), anal and spiny and soft dorsal fins. The red stripe through the anal and spiny and soft dorsal fins are topped with a tiny iridescent blue-white stripe. These red and iridescent blue-white stripes are somewhat subtle on most of the fins but are prominent and eye-catching on the spiny dorsal fin.

Western carp gudgeons spawn in summer, attaching eggs to aquatic weed in the shallows. There is some suggestion that they have suffered from small variations in river level caused by river regulation, which expose and destroy eggs laid in shallows. There is also some suggestion that they are/were a critical food item for juvenile Murray cod. It is likely they are an important forage fish for larger fish species in many waterways. Western carp gudgeons have taken to lower altitude man-made lakes and impoundments in the Murray-Darling system well, and are very common in some.

In aquaria

Western carp gudgeon make superb aquarium fish: they are lively, interactive, attractively coloured and hardy. They eagerly take brine shrimp, live or frozen, and very small invertebrates. Curiously, they are unavailable in aquarium stores and remain the province of keen naturalists who capture their own (readily done with a sweep net around weedbeds in summer).

Classification

Western carp gudgeon are purportedly the most common of the carp gudgeons (lake's carp gudgeon and midgley's carp gudgeon are the other proposed species). However, recent genetic research suggests that the carp gudgeons are a cryptic species complex composed of at least four species and many hybrids; their taxonomy is extremely complicated, unresolved and not accurately reflected by current scientific and common names.

Many researchers have now resorted to referring to them as simply "carp gudgeon ("Hypseleotris spp.")" until their taxonomy is resolved.

External links

* [http://www.nativefish.asn.au/wcarpgud.html Native Fish Australia]

References

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* Bertozzi, T., Adams, M. and Walker, K.F. (2000) Species boundaries in carp gudgeons (Eleotrididae: Hypseleotris) from the River Murray, South Australia: evidence for multiple species and extensive hybridization. "Marine and Freshwater Research" 51: 805–815.