Tripod Spiderfish, Bathypterois grallator (Goode & Bean 1886)

Other Names: Tripodfish

A Tripod Spiderfish, Bathypterois grallator, on Mona Slide in the Caribbean, depth 1996-2022 m. Source: Ocean Exploration Trust / WoRMS. License: CC By Attribution-NonCommercial-ShareAlike

A spiderfish with extremely long caudal and pelvic-fin rays that are longer than the standard length of the fish, relatively short pectoral fins, and no adipose fin.

Tripod Spiderfish rest motionless on the abyssal plain on their extremely long pelvic and caudal fins. They face into the current, holding their long pectoral fins upright or forwards to sense prey items drifting by in the current.
Specialized pads on the tips of the pelvic and caudal fins allow the tripodfish to perch up off the soft sediment.
Video of a Tripod Spiderfish at a depth of 750 metres.

Cite this page as:
Bray, D.J. 2018, Bathypterois grallator in Fishes of Australia, accessed 02 Dec 2021,

Tripod Spiderfish, Bathypterois grallator (Goode & Bean 1886)

More Info


Recorded in Australia from off Northwest Cape, Western Australia, and off eastern Australia. Elsewhere, the species is widespread in the Indo-west-central-Pacific and Atlantic oceans. Inhabits continental slope and abyssal plain waters.


Gular fold scaled; 10-13 anal fin rays; 13-15 pectoral-fin rays (incl. rudiments), rays 3 and 4 closely applied but unfused, rays 5 through 9 never rudimentary; first pelvic-fin ray strengthened and greatly elongated (greater than 100% SL), second fin ray thin, half as long as the first, and closely applied to it; lower caudal-fin ray(s) greatly produced (38-134% SL); vomer with two large elliptical tooth patches; basibranchial 3-4 with dentigerous dermal plates; 34-37 rakers on the anterior gill arch; lateral-line scales 58-60; Vertebrae 53-54; .


Color uniform black.


Their extremely long caudal and pelvic rays enables Tripod Spiderfish to "stand" up off the bottom. They often orientate their pectoral fins in an upright or forward position, which may be a sensory mechanism for detecting the movement of prey and feed mostly on benthopelagic organisms such as small crustaceans and gelatinous plankton drifting by in the current.


Spiderfishes are synchronous hermaphrodites, and have ovotestes containing functional male and female reproductive tissue.

Species Citation

Benthosaurus grallator Goode & Bean, 1886, Bull. Mus. Comp. Zool. 12(5): 168. Type locality: Gulf of Mexico, off northern Florida and off New Jersey.


Bray, D.J. 2018


Australian Faunal Directory

Tripod Spiderfish, Bathypterois grallator (Goode & Bean 1886)


Bannerman, P., Poss, S., Russell, B. & Nunoo, F. 2015. Bathypterois grallator. The IUCN Red List of Threatened Species 2015: e.T194992A15571915. Downloaded on 27 May 2017.

Carrasson, M. & Matallanas, J. 2001. Feeding ecology of the Mediterranean Spiderfish, Bathypterois mediterraneus (Pisces: Chlorophthalmidae), on the western mediterranean slope. Fishery Bulletin 99(2): 266-274. PDF available Open access

Chave, E.H. & Mundy, B.C. 1994. Deep-sea benthic fish of the Hawaiian Archipelago, Cross Seamount, and Johnston Atoll. Pacific Science 48: 367-409.

Crabtree RE, Carter HJ, Musick JA. 1991. The comparative feeding ecology of temperate and tropical deep-sea fishes from the western North Atlantic. Deep-Sea Research 38:1277-1298.

Davis, M.P. & Chakrabarty, P. 2011. Tripodfish (Aulopiformes: Bathypterois) locomotion and landing behaviour from video observation at bathypelagic depths in the Campos Basin of Brazil. Marine Biology Research 7(3): 279-303 Abstract

Franco MAL, Braga AC, Nunan GWA, Costa PAS. 2009. Fishes of the family Ipnopidae (Teleostei: Aulopiformes) collected on the Brazilian continental slope between 118 and 238S. Journal of Fish Biology 75: 797-815.

Gartner JV, Crabtree RE, Sulak KJ. 1997. Feeding at depth. Chapter 4, pp 115-193. In: Randall DJ, Farrell AP (eds) Physiology of Deep-Sea Fishes, Vol. 16. San Diego, California: Academic Press,.

Goode, G.B. & Bean, T.H. 1886. Reports on the results of dredging under the supervision of Alexander Agassiz, in the Gulf of Mexico (1877–78) and in the Caribbean Sea (1879–80), by the U.S. Coast Survey Steamer Blake, Lieut. Commander C.D. Sigsbee, U.S.N., and Commander J.R. Bartlett, U.S.N., commanding. 28. Description of thirteen species and two genera of fishes from the Blake collection. Bulletin of the Museum of Comparative Zoology, Harvard 12(5): 153-170.

Jones, A.T. & Sulak, K.J. 1990. First central Pacific plate and Hawaiian record of the deep-sea tripod fish Bathypterois grallator (Pisces: Chlorophthalmidae). Pacific Science 44: 254-257.

Sulak KJ. 1977. The systematics and biology of Bathypterois (Pisces: Chlorophthalmidae) with a revised classification of benthic myctophiform fishes. Galathea Report 14: 49-108. PDF availalble, open access

Williams, A., Last, P.R., Gomon, M.F. & Paxton, J.R. 1996. Species composition and checklist of the demersal ichthyofauna of the continental slope off Western Australia (20–35º). Records of the Western Australian Museum 18: 135-155.

Quick Facts

CAAB Code:37123007

Biology:Synchronous hermaphrodite

Conservation:IUCN Least Concern

Depth:900-4,720 m

Habitat:Bottom dweller

Max Size:37 cm SL

Species Image Gallery

Species Maps

CAAB distribution map