Duckbill Flagfin, Leptaulopus erythrozonatus Gomon, Struthers & Stewart 2013

Other Names: Fourfinger

Holotype of the Duckbill Flag, Leptaulopus erythrozonatus, NMNZ P.042518, 271 mm SL, from the Bay of Plenty, New Zealand. Source: Carl Struthers, Fig. 5C, in Gomon et al. (2013) Species Diversity 18: 141-161. License: All rights reserved

A mottled dusky brown threadsail becoming paler below, with four irregular darker bands, narrow reddish-orange to brownish stripes on the dorsal fin, and a pale caudal fin with 4-5 narrow reddish bands across each lobe.

Cite this page as:
Bray, D.J. 2018, Leptaulopus erythrozonatus in Fishes of Australia, accessed 09 Dec 2022,

Duckbill Flagfin, Leptaulopus erythrozonatus Gomon, Struthers & Stewart 2013

More Info


Off Batemans Bay, New South Wales. Elsewhere the species occurs in New Zealand. In New Zealand, the fish have been taken on rod and line from shelly to cobble bottoms.


Dorsal fin 15-16; anal fin 10-11; Pectoral fin 12; Pelvic fin 9; Caudal fin 19-20; Lateral-line scales 44; Gill rakers 2-3 + 12 = 14-15; Vertebrae 44.
Head and body elongate, slender, flattened ventrally; head moderate 3.1-34% SL; snout relatively long, somewhat depressed. Small caniform teeth present in broad bands on jaws, vomer, palatines and tongue.
Dorsal fin originating just behind a vertical through pelvic-fin origin, fin moderately tall anteriorly, somewhat lower posteriorly; first two rays simple, rest branched, last split to base. Caudal fin forked. 

Similar Species

Differs from Leptaulopus damasi in having 15-16 dorsal-fin rays (vs 13 or 14), 44 lateral line scales (vs 33–37), 44 vertebrae (vs 36), a smaller eye, and a longer, more depressed snout.


The specific name erythrozonatus is a combination of the Greek erythros for ‘red’ and zone for ‘belt’ in reference to the distinctive red bands on the dorsal and caudal fins.

Species Citation

Leptaulopus erythrozonatus Gomon, Struthers & Stewart 2013, Species Diversity 18: 157, figs1, 2C, 5C, D. Type locality: Penguin Rise, Bay of Plenty, New Zealand [37°24.29'S, 176°24.83'E]. 


Bray, D.J. 2018


Australian Faunal Directory

Duckbill Flagfin, Leptaulopus erythrozonatus Gomon, Struthers & Stewart 2013


Gomon, M.F., Stewart, A.L. & Struthers, C.D. 2015. Family Aulopidae. pp. 538-540 in Roberts, C.D., Stewart, A.L. & Struthers, C.D. The Fishes of New Zealand. Wellington : Te Papa Press Vol. 2 pp. 1-576. 

Gomon, M.F., Struthers, C.D. & A.L. Stewart. 2013. A new genus and two new species of the family Aulopidae (Aulopiformes), commonly referred to as Aulopus, flagfins, Sergeant Bakers or Threadsails, in Australasian waters. Species Diversity 18: 141-161

Roberts, C.D., Paulin, C.D., Stewart, A.L., McPhee, R.P. & McDowall, R.M. 2009. Checklist of New Zealand Chordata: living lancelets, jawless fishes, cartilaginous fishes and bony fishes, pp. 529– 538 in Gordon, D.P. (ed.) The New Zealand Inventory of Biodiversity. Vol. 1. Kingdom Animalia. Canterbury University Press, Christchurch, 568 pp (as Aulopodidae n. gen et n. sp.)

Shimizu, T. & Yamakawa, T. 1989. Review of the genera and western Pacific species of the Aulopidae. Third Indo-Pacific Fish Conference, Wellington, New Zealand, unpublished poster.

Quick Facts

CAAB Code:37117006

Depth:135-177 m

Habitat:Reef associated

Max Size:27+ cm SL

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