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Boofhead carp Gudgeon

Other common name(s): 
Scientific name: 
Hypseleotris bucephala
Thacker, Geiger & Unmack, 2022
Gunther Schmida
Threatened but recovering


Part of the complex of the sexual species (Boofhead) and hemiclones (between Bald and Boofhead, and Boofhead and Cryptic) previously known as Midgley’s carp gudgeon (Hypseleotris species B).

Boofhead carp gudgeon can be distinguished from other sexual species of the MDB carp gudgeon complex by having a very blunt head, a rounded snout profile, with dorsal scales present (as opposed to Bald with no dorsal scales). Boofhead lack the longer, pointed median fin tips on the second dorsal and anal fins of Cryptic carp gudgeon. Colouration of second dorsal and anal fins in breeding males is unique, with outer half of fin possessing red, black, and orange bands, often with thin white edge.

Female fin colour is clear. Always with scales on dorsal head and nape. These scales can vary from well-developed imbricate (overlapping with narrow margins) to scattered, small, or cycloid. Some fish are poorly scaled without scales on the dorsal midline, but always with scales elsewhere on head.  

Biology and Habitat

No specific wild field studies have been conducted on this species alone (as opposed to studies on ‘Midgleys’ carp gudgeon or generic Hypseleotris spp). However reproductive behaviour in aquaria has been documented for ‘Midgley’s’ which provides a useful guide to what likely occurs with Boofhead carp gudgeon.  Aquarium spawning’s have occurred from late November to early January at water temperatures of 20-24 °C. Eggs were laid on the roof of a cave and guarded by the male, with the male aggressively chasing other males away. Up to 400 eggs (~0.8 mm diam) are laid which hatch in 6-9 days. Eggs are laid in random trails, often linear, with the eggs relatively widely spaced (up to 4 mm apart). Fry are ~4 mm length on hatching. Males can spawn with multiple females over a season.  

The dietary ecology and habitat use of ‘Midgley’s’ has been studied in selected floodplain ponds of the Ovens River in Vic and gives a good indication of the ecology of Boofhead carp gudgeon in such environments. The ponds studied were largely free of predatory fish (Redfin perch). This study found that small gudgeons < 24 mm standard length (SL) (~ 30mm total length) were generally associated with surface and benthic habitats, but large gudgeons (>24 mm SL) then restricted their distribution to benthic habitats. Small gudgeons consumed mainly chironomids, Cladocera, rotifers and copepods whereas large gudgeons consumed mainly chironomids, algae and detritus. Some piscivory was recorded in larger gudgeons. The diets of small gudgeons and mosquitofish were very similar.

Distribution and Abundance

The species and its hemiclones (involving Bald and Cryptic carp gudgeon) are widespread and abundant throughout the MDB. The species is also present in the adjacent Bulloo River, Cooper Creek, and eastern coastal streams from the Tully River south to around the Brisbane River.  It has also been recently recorded from the Gulf of Carpentaria. The distribution map only shows confirmed genetic records of this species (no hemiclones or unverified records). Records of this newly described species would also be included within the general ‘carp gudgeon’ map, but the taxonomic confusion means that these records cannot be separated out.  

Potential Threats

None known. Predation by alien fish such as Redfin perch in floodplain ponds/billabongs can significantly reduce local abundance.

General References

Bertozzi et al. 2000; Leggett & Merrick 1987; Stoffels & Humphries 2003; Thacker et al. 2022; Unmack 2000; Unmack et al. 2019; Unmack & Hammer 2021.

This species account is an extract from Fishes of the Murray-Darling Basin (second edition) and should be cited as "Lintermans, M. 2023, Fishes of the Murray–Darling Basin, Australian River Restoration Centre, Canberra."

Other Fish in this family

Front book cover of Fishes of the Murray–Darling Basin

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The second edition of Fishes of the Murray-Darling Basin by Mark Lintermans is available now! This edition has been fully revised, incorporating new ecological knowledge on each species and additional species accounts.

Fishes of the Murray-Darling Basin remains the only book of its kind, devoted exclusively to the fishes of Australia’s largest river system, containing rigorous information on the identification, habitats, biology and distribution of the freshwater fish of the Murray-Darling Basin, as well as background information on the threats to fish and aquatic ecosystems. It is an invaluable resource for naturalists, students, fishers, scientists and anyone else interested in the life within our rivers.

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