Tadpole Whiptail, Squalogadus modificatus Gilbert & Hubbs 1916

Other Names: Balloonhead Rattail

Tadpole Whiptail, Squalogadus modificatus. Source: Australian National Fish Collection, CSIRO. License: CC by Attribution-NonCommercial-ShareAlike

A dark brown grenadier, becoming blackish around the gill openings, with the inside of the mouth and gill cover black. The species has a massive inflated head, tiny eyes, a continuous dorsal fin, small pelvic fins, and no chin barbel.

Cite this page as:
Bray, D.J. 2022, Squalogadus modificatus in Fishes of Australia, accessed 10 Jun 2023, https://fishesofaustralia.net.au/Home/species/1704

Tadpole Whiptail, Squalogadus modificatus Gilbert & Hubbs 1916

More Info


NW of Mandurah to west of Barrow Island, Western Australia, and on the Queensland Plateau in the Coral Sea, E of Townsville; also the Lord Howe Plateau and Norfolk Ridge in the Tasman Sea. Elsewhere the species is widespread in the tropical and temperate, Atlantic-Indo-west-central Pacific.
Inhabits seamounts, ridges and rises, at mid-water and benthopelagic levels. 


Pelvic fin 5, rays tiny; Branchiostegal rays 7.
Head massive, inflated, with rounded corners; head fully scaled, mandibular band narrow. Orbit tiny, about 10% of head length, placed forward of small, inferior mouth. Chin barbel absent. Opercular cavity large, operculum extending well beyond gills; first gill slit not restricted by membranous folds of skin, outer gill rakers numerous (20), long, slender. Jaws relatively short; markedly inferior. Anus immediately before anal fin. One continuous dorsal fin, anterior section not elevated. Pelvic fins small, with five rays. Tail strap-like. Anal fin long, poorly developed. No light organ. Swim bladder regressed.


Feeds mostly on pelagic copepods, and also on pelagic mysids, shrimps, cephalopods, fishes, polychaetes and gastropods.


The specific name modificatus possibly refers to the extremely modified bulbous head of this species.

Species Citation

Squalogadus modificatus Gilbert & Hubbs 1916, Proc. U. S. Natl Mus. 51(2149): 156. Type locality: Bungo Channel, 32°32'N, 132°25'E, off Kyushu, Japan, Albatross station 4956, depth 720 fathoms. 


Bray, D.J. 2022


Atlas of Living Australia

Tadpole Whiptail, Squalogadus modificatus Gilbert & Hubbs 1916


Gilbert, C.H. & Hubbs, C.L. 1916. Report on the Japanese macruroid fishes collected by the United States Fisheries steamer "Albatross" in 1906, with a synopsis of the genera. Proceedings of the United States National Museum 51(2149): 135-214. 

Iwamoto, T. 1999. Families Macrouridae, Bathylagidae, Moridae, Bregmacerotidae. pp. 1986-1998 in Carpenter, K.E. & Niem, V.H. (eds) The Living Marine Resources of the Western Central Pacific. FAO Species Identification Guide for Fisheries Purposes. Rome : FAO Vol. 3 pp. 1397-2068. 

Iwamoto, T. 2015. Squalogadus modificatus. The IUCN Red List of Threatened Species 2015: e.T190237A15603025. https://dx.doi.org/10.2305/IUCN.UK.2015-4.RLTS.T190237A15603025.en. Accessed on 16 August 2022.

Iwamoto, T., Nakayama, N., Shao, K.-T. & Ho, H.-C. 2015. Synopsis of the Grenadier fishes (Gadiformes; Teleostei) of Taiwan. Proceedings of the California Academy of Sciences (Series 4) 62(3): 31-126. See ref at BHL

Iwamoto, T. & Williams, A. 1999. Grenadiers (Pisces, Gadiformes) from the continental slope of western and northwestern Australia. Proceedings of the California Academy of Sciences 51(3): 105-243 figs 1-58 See ref at BHL

McMillan, P. J. & Iwamoto, T. 2015. Family Macrouridae. pp. 747-827 in Roberts, C.D., Stewart, A.L. & Struthers, C.D. The Fishes of New Zealand. Wellington : Te Papa Press Vol. 3 pp. 577-1152.

Quick Facts

CAAB Code:37232070

Conservation:IUCN Least Concern

Depth:600-1740 m

Habitat:Benthopelagic, mesopelagic, Continental Slope

Max Size:35 cm TL

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