Nurseryfish occur in turbid, coastal, brackish and fresh water in southern New Guinea and northern Australia, including the following rivers: Pentecost (WA); East Baines, Daly, Finnis, Adelaide, Mary, Wildman and West, South and East Alligator (NT); Leichardt, Saxby and Norman (Qld).
The most remarkable feature of this species is that the males have a hook on their head to which the eggs become attached. The hook is formed from the supraoccipital crest and is covered with highly vascularized skin. Nurseryfish are a hatchet-shaped, hump-headed, very compressed fish with a long anal fin (2 spines and 40–48 rays) and a narrow caudal peduncle. The dorsal fin is short with 2 spines and 11–14 rays. The caudal fin is deeply forked with pointed lobes. Muscle chevrons are visible along the sides of the fish. The body is covered with fine, cycloid scales, and the lateral line is very short. The mouth is large, and the anus is located farther forward than in most fishes. They have a silvery body, with a neon violet coloration. They routinely reach 30 cm and can grow twice that size.
Ecology/Way of Life:
The males carry the eggs on their hook like a cluster of grapes. How the eggs become attached to the hook is unknown. Nurseryfish feed on prawns, isopods, insect larvae, and small fishes. They are extremely delicate and difficult to keep in captivity. Further information on spawning season, larval development, anatomical and histological modifications of the hook, taxonomic comparison with Indian Hump Head (Kurtus indicus) from south-east Asia, and phylogenetic placement will be forthcoming.
Interaction with Humans/Threats:
Nurseryfish occur in large, remote river systems and are not threatened. Saltwater crocodiles (Crocodylus porosus), also inhabit the same systems. Commercial Barramundi fishers frequently take Nurseryfish in their gill nets and report they are excellent eating, earning the name of breakfast fish. Anglers rarely catch Nurseryfish on rod and reel.
Kurtus gulliveri was named by Castelnau in 1878. The genus name is based on Greek, Kurt meaning curved. The species name gulliveri is named for Mr. Gulliver, a resident of the small settlement near the Norman River, Qld who supplied the specimen to Castelnau.
Allen, G. R., Midgley, S. H. & Allen, M. (2002). Field Guide to the Freshwater Fishes of Australia. Western Australian Museum. Perth. 394pp.
Berra, T. M. (2001). Freshwater Fish Distribution. Academic Press. San Diego, CA. 604pp.
Berra, T. M. & Humphrey, J. (2002). Gross anatomy and histology of the hook and skin of male nurseryfish, Kurtus gulliveri, from northern Australia. Environmental Biology of Fishes. 65: 263–270.
Berra, T. M. & Wedd, D. (2001). Alimentary canal anatomy and diet of the nurseryfish, Kurtus gulliveri (Perciformes: Kurtidae), from the Northern Territory of Australia. The Beagle, Records of the Museums and Art Galleries of the Northern Territory 17: 21–25.
Merrick, J. R. & Schmida, G. E. (1984). Australian Freshwater Fishes: Biology and Management. Griffith Press Ltd. 409pp.
Text: Tim M. Berra. Distribution map: Peter J. Unmack. Photographer: Gunther Schmida.
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