Bigeye Thresher, Alopias superciliosus (Lowe 1841)

Bigeye Thresher, Alopias superciliosus. Source: Australian National Fish Collection, CSIRO. License: CC by Attribution-NonCommercial


A brownish to purplish-grey thresher shark with a uniform creamy-white underside, very large eyes that extend onto the top of the head, and a deep groove above each eye. The first dorsal fin is set far back on the body, and the upper tail lobe is very long. 

Cite this page as:
Bray, D.J. 2023, Alopias superciliosus in Fishes of Australia, accessed 21 Jun 2024,

Bigeye Thresher, Alopias superciliosus (Lowe 1841)

More Info


North West Shelf, Western Australia, and the northern Great Barrier Reef to off South Australia, including eastern Tasmania; also the Lord Howe Province in the Tasman Sea. Elsewhere, the species occurs worldwide in tropical to temperate oceanic waters on the continental shelf and slope.

Although pelagic, oceanic shark occasionally enters shallower waters around seamounts and the edges of outer reefs, individuals mostly occur in deeper waters during the day. 


Distinct grooves from top of head behind eyes to above gill slits; very large eyes extending onto the top part of the head. First dorsal fin set well back on the body with the rear of fin above origin of pelvic fins; pectoral fins very large with broad tips; upper caudal-fin lobe about equal in length to rest of body.


To 490 cm TL


Metallic brownish to purplish-grey above, creamy white below.


The Bigeye Thresher feeds mostly on small pelagic fishes and squid. Thresher sharks have an unusual hunting method – herding schools of small pelagic fishes towards the surface then stunning prey with the long whip-like tail. 


Thresher sharks are aplacental viviparous. The embryos develop in a primitive uterus within the female, where they feed on yolk-filled egg capsules continually produced by the mother for the developing young to consume. This is a form of intra-uterine (within-the-uterus) cannibalism, known as oophagy or oviphagy (Smith et al. 2008). Female Bigeye Threshers give birth to litters of 2-4 pups.


Taken as a target species and as bycatch throughout its range in gillnet, longline and trawl fisheries. The flesh is marketed fresh, dried or salted and the fins are sold in the Asian shark fin trade. The species is also caught by recreational anglers.


  • IUCN Red List : Endangered.
  • The Bigeye Thresher occurs within the range of many largely unregulated gillnet and longline fisheries, and is especially vulnerable to fisheries exploitation (target and bycatch).


    Thresher sharks, like other mackeral sharks, have a highly-developed vascular exchange system called the 'rete mirabile' around the brain and eyes, thought to keep the brain and eyes considerably warmer than the surrounding water temperature during deep dives into cold water.

    Similar Species

    Differs from the other species of thresher shark, Alopius pelagicus and Alopias vulpinus, in having the following combination of characters: a pair of deep grooves on the top of the head; the large, vertically expanded eyes extend onto the top of the head; the long upper lobe of the caudal fin is broader that in the other species; the first dorsal fin is placed further back on the body with the free rear tip positioned above or just before the pelvic fins.


    The specific name superciliosus is from the Latin super (= above), and ciliosus (= eyebrow), in reference to the deep groove above each eye.

    Species Citation

    Alopecias superciliosus Lowe 1841, Proc. Zool. Soc. Lond. 1840 8(89): 39. Type locality: Madeira.


    Bray, D.J. 2023


    Atlas of Living Australia

    Bigeye Thresher, Alopias superciliosus (Lowe 1841)


    Chen, C.-T., Liu, K.-M. and Chang, Y.-C. 1997. Reproductive biology of the bigeye thresher shark, Alopias superciliosus (Lowe, 1939) (Chondrichthyes: Alopiidae), in the northwestern Pacific. Ichthyological Research 44(3): 227-235.

    Compagno, L.J.V. 1984. FAO species catalogue. Vol. 4. Sharks of the world. An annotated and illustrated catalogue of shark species known to date. Part 1. Hexanchiformes to Lamniformes. FAO, Rome.

    Compagno, L.J.V. 1990. Shark exploitation and conservation. In: H.L. Pratt, Jr., S.H. Gruber & T. Taniuchi (eds). Elasmobranchs as living resources: Advances in the biology, ecology, systematics and the status of the fisheries. NOAA Techncal Report. NMFS.

    Compagno, L.J.V. 2001. Sharks of the World: An Annotated and Illustrated Catalogue of Shark Species Known to Date. Volume 2. Bullhead, Mackerel and Carpet Sharks (Heterodontiformes, Lamniformes and Orectolobiformes). FAO. Rome, Italy.

    Gilmore, R.G. 1983. Observations on the embryos of the Longfin Mako, Isurus paucus, and the Bigeye Thresher, Alopias superciliosus. Copeia 1983(2): 375–382.

    Gilmore, R.G. 1993. Reproductive biology of lamnoid sharks. Environmental Biology of Fishes 38: 95-114.

    Gruber, S.H.& Compagno, L.J.V. 1981. Taxonomic status and biology of the bigeye thresher, Alopias superciliosus (Lowe, 1839). Fishery Bulletin of the National Marine Fisheries Service 79(4): 617-640.

    Last, P.R. & Stevens, J.D. 2009. Sharks and Rays of Australia. Collingwood : CSIRO Publishing Australia Edn 2, 550 pp.

    Lowe, R.T. 1841. Description of some new species of Madeiran fishes, with additional information relating to those already described. Proceedings of the Zoological Society of London 8: 36-39 See ref at BHL

    Macbeth, W.G., Vandenberg, M. & Graham, K.J. 2008. Identifying Sharks and Rays; A guide to Commercial Fishers. Sydney : New South Wales Department of Primary Industry 71 pp.

    Nakano, H., Matsunaga, H., Okamoto, H. & Okazaki, M. 2003. Acoustic tracking of bigeye thresher shark Alopias superciliosus in the Eastern Pacific Ocean. Marine Ecology Progress Series 265: 255-261.

    Patterson, J.C., Sepulveda, C.A. & Bernal, D. 2011. The vascular morphology and in vivo muscle temperatures of thresher sharks (Alopiidae). Journal of Morphology 272(11): 1353-1364.

    Pepperell, J. 2010. Fishes of the Open Ocean a Natural History & Illustrated Guide. Sydney : University of New South Wales Press Ltd 266 pp.

    Rigby, C.L., Barreto, R., Carlson, J., Fernando, D., Fordham, S., Francis, M.P., Herman, K., Jabado, R.W., Liu, K.M., Marshall, A., Pacoureau, N., Romanov, E., Sherley, R.B. & Winker, H. 2019. Alopias superciliosus. The IUCN Red List of Threatened Species 2019: e.T161696A894216. Accessed on 19 July 2023.

    Sepulveda, C.A., Wegner, N.C., Bernal, D. & Graham, J.B. 2005. The red muscle morphology of the thresher sharks (family Alopiidae). Journal of Experimental Biology 208(22): 4255–4261.

    Weng, K.C. & Block, B.A. 2004. Diel vertical migration of the Bigeye Thresher Shark (Alopias superciliosus), a species possessing orbital retia mirabilia. Fishery Bulletin 102: 221–229.

    White, W.T. 2008. Shark Families Heterodontidae to Pristiophoridae. pp. 32-100 in Gomon. M.F., Bray, D.J. & Kuiter, R.H (eds). Fishes of Australia's Southern Coast. Sydney : Reed New Holland 928 pp.

    Quick Facts

    CAAB Code:37012002

    Conservation:IUCN Endangered

    Danger:Thrashing tail, sharp teeth

    Depth:0-723 m

    Fishing:Commercial, recreational

    Habitat:Oceanic, pelagic

    Max Size:490 cm TL

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