Hypseleotris klunzingeri
Western Carp Gudgeon
Species Summary
The most widespread of the south-eastern Australian carp gudgeons, Hypseleotris klunzingeri is found throughout much of the Murray–Darling Basin as well as coastal drainages of southern Queensland, New South Wales and Victoria, and has more recently turned up as an apparent introduction in the far-north Queensland Wet Tropics, at Groves Creek near Speewah — genetic evidence traces that population back to source stock near Childers, hundreds of kilometres to the south.
Breeding
Hypseleotris klunzingeri appears to have first been bred in captivity in 1928 by Clarence Blewett, who noticed a male attempting to entice a female into his territory, separated the pair into their own tank, and was rewarded with a spawning three days later — not among the rocks he had provided, but around 5 cm below the water’s surface. Field research by John Lake at Narrandera, NSW, recorded spawning at 22.5 °C in shallow water 5–25 cm deep, following males nudging receptive females; eggs (0.4–0.5 mm) are laid on sticks or grass, with individual females carrying up to 2,000 ova, and males guard the clutch in a vertical, head-up-or-down posture until hatching, 47–53 hours later. Newly hatched larvae are just 1.8–2.1 mm and drift head-first towards the bottom before abruptly reversing to swim vertically for a few centimetres; free-swimming by day 6, none in Lake’s study survived beyond 9 days for lack of suitably sized food. A separate observed spawning, from Murray River fish, matched this timeline closely: eggs first seen at 10 pm, hatching by the following evening (42 hours later) at around 17 °C, with fry around 3 mm drifting tail-up and head-down before disappearing within two days, likely eaten by the adults.
Carp gudgeons (genus Hypseleotris) are a notoriously confusing group even for experienced native-fish keepers: several look-alike species can share the same waterway, few people can reliably tell them apart on sight, and published photographs in field guides have historically been misidentified more often than not. Presently around eleven described and undescribed species are recognised from Australia. Collecting your own is the only realistic way to keep most of them, since none are commercially bred or offered for sale; all mature at around 3 cm, and males tend to set up territory in a small cave, tube or flowerpot, where they will also spawn, so a tank furnished with several potential spawning sites suits a group well. Wild-caught fish are often initially reluctant to take live-then-frozen brine shrimp or bloodworm, but usually come around; most species tolerate 4–37 °C and are most comfortable around 15–25 °C. Reported captive lifespans run to 3–5 years for most carp gudgeons.
Compiled for Home of the Rainbowfish from ANGFA sources: P. J. Unmack, “The genus Hypseleotris of southeastern Australia, its identification and breeding biology”, Fishes of Sahul 14, 2000, pp. 645–657; K. Martin, M. P. Hammer & P. J. Unmack, “New locality records for carp gudgeons (Hypseleotris spp) in the Queensland Wet Tropics”, Fishes of Sahul 35, 2021, pp. 1745–1749.