Freshwater Longtom, Strongylura krefftii (Günther 1866)

Other Names: Fitzroy Garpike, Fitzroy Gar-pike, Freshwater Long Tom, Freshwater Long-tom, Long Tom

Freshwater Longtom, Strongylura krefftii, from the Fitzroy River, Kimberley, Western Australia. Source: David Morgan / Freshwater Fish Group & Fish Health Unit, Murdoch University. License: All rights reserved

A silvery to olive-green longtom often with a blue tinge below, and translucent to yellowish or slightly dusky fins.

Cite this page as:
Gomon, M.F. & D.J. Bray. 2010, Strongylura krefftii in Fishes of Australia, accessed 24 May 2024,

Freshwater Longtom, Strongylura krefftii (Günther 1866)

More Info


Found in coastal rivers of tropical Australia and New Guinea. In Australian waters, the Freshwater Longtom is known from the Fitzroy River, WA (17º45´S) to the Dawson River, QLD (24º33´S). Although a number of authors have recorded this species from northern NSW, there are no reliable records could be found. The Freshwater Longtom lives in still or flowing water of larger rivers from tidal reaches to well inland, with adults sometimes found in coastal marine waters. Habitats include main river channels, floodplain lagoons, muddy creeks, escarpment streams, lagoons and billabongs; often shelters amongst overhanging vegetation or submerged roots. The species has a wide temperature tolerance in northern Australia, from about 23-38°C.


Dorsal fin 16-18; Anal fin 19-21; Pectoral fin 11-12; Pelvic fin 6.
Body elongate and slender; greatest body depth 10-25 in SL; jaws greatly elongate, 25% SL, needle-like and of equal length; jaws with numerous small sharp teeth; head large, HL 2.3-2.4 in SL; eye relatively small, 2.8-3.3 in postorbital part of head; lateral line present.
Scales small, cycloid, easily detached.
Fins without spines; dorsal and anal fins positioned posteriorly with bases opposite; ventral fins abdominal, midway between preopercle and tail base; short pectoral fins located high on sides; caudal fin emarginate to truncate.


To 85 cm SL, commonly 30-40 cm.


Silvery to olive green overall often with a blue tinge ventrally; fins translucent to yellowish or slightly dusky.


Feed at night in shallow water mainly preying on small fishes, as well as crustaceans and surface-dwelling insects. Adults feed almost entirely on fishes. Reportedly launches ambush attacks on smaller fishes form the cover of overhanging vegetation.


Little is known of the breeding biology of this species however spawning is thought to occur in freshwater between September and December. Females lay small eggs, 2 mm diam., presumably with adhesive filaments that attach to aquatic plants. Larvae presumably pelagic.


The Freshwater Longtom will take a lure and may also attack smaller fishes that have been caught on hook and line. The Longtom is reportedly a good-eating fish, although very bony.

Species Citation

Belone krefftii Günther, 1866, Cat. Fishes Brit. Mus. 6: 250. Type locality: Australia (="Sydney, N.S.W").


Gomon, M.F. & D.J. Bray. 2010

Freshwater Longtom, Strongylura krefftii (Günther 1866)


Allen, G.R. 1982. Inland Fishes of Western Australia.  Perth : Western Australian Museum 86 pp.

Allen, G.R. 1989. Freshwater Fishes of Australia.  Neptune, New Jersey : T.F.H. Publications pp. 1–240

Allen, G.R., Midgley, S.H. & Allen, M. 2002. Field guide to the freshwater fishes of Australia.  Perth : Western Australian Museum 394 pp. [125].

Grant, E.M. 1975. Guide to Fishes.  Brisbane : Co-ordinator-General Department 3rd Edn  640 pp. [105] (as Stenocaulus kreffti)

Larson, H.K. & Martin, K.C. 1990. Freshwater Fishes of the Northern Territory. Northern Territory Museum of Arts and Sciences Handbook Series Number 1.  Darwin : Northern Territory Museum of Arts and Sciences 102 pp.

Merrick, J.R. & Schmida, G.E. 1984. Australian Freshwater Fishes Biology and Management.  Sydney : J.R. Merrick 409 pp.

Morgan, D.L., M.G. Allen, P. Bedford & M. Horstman. 2004. Fish fauna of the Fitzroy River in the Kimberley region of Western Australia – including the Bunuba, Gooniyandi, Ngarinyin, Nyikina and Walmajarri Aboriginal names. Records of the Western Australian Museum 22: 147–161.

Pusey, B.J, Kennard, M.J. & A.H. Arthington. 2004. Freshwater Fishes of North-Eastern Australia. CSIRO Publishing, Collingwood, Victoria.

Pusey, B.J, Kennard, M.J. & Bird, J. 2000. Fishes of the dune fields of Cape Flattery, northern Queensland and other dune systems in north-eastern Australia. Ichthyol. Explor. Freshw. 11(1): 65–74.

Quick Facts

CAAB Code:37235009

Depth:1-10 m

Habitat:Coastal rivers

Max Size:85 cm SL

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