Pelagic Thresher, Alopias pelagicus Nakamura 1935

Other Names: Small Tooth Thresher Shark

A Pelagic Thresher Shark, Alopias pelagicus. Source: Klaus Stiefel / Flickr (pacificklaus). License: CC BY Attribution-Noncommercial


A strong-swimming active shark with an enormous tail and large eyes.

Identifying features:
Upper caudal-fin lobe enormous, longer than rest of body;
Eyes large, positioned on side of head;
Middle of first dorsal-fin base closer to free tips of pectoral fins than to pelvic fins;
Pectoral fins almost straight with broadly-rounded tips;
Pale greyish above, underside whitish.

Thresher sharks scythe-like tails to prey on schooling fishes such as sardines. By rapidly slapping the enormous tail, the thresher shark can stun several fishes at a time. 

Video of a Pelagic Thresher at Malapascua Island in the Philippines

Cite this page as:
Dianne J. Bray, Alopias pelagicus in Fishes of Australia, accessed 16 Jul 2019,

Pelagic Thresher, Alopias pelagicus Nakamura 1935

More Info



The smallest of the three recognised species of thresher shark, reaching 3.65 m TL.


Pelagic thresher sharks are late to mature and have low fecundity.


  • EPBC Act 1999 : Not listed
  • IUCN Red List : Vulnerable
  • Author

    Dianne J. Bray

    Pelagic Thresher, Alopias pelagicus Nakamura 1935


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    Compagno, L.J.V. 2001. Sharks of the World. An annotated and illustrated catalogue of shark species known to date. Bullhead, mackerel and carpet sharks (Heterodontiformes, Lamniformes and Orectolobiformes). Rome : FAO, FAO Species Catalogue for Fisheries Purposes No. 1 Vol. 2 269 pp.

    Compagno, L.J.V., Dando, M. & Fowler, S. 2005. A Field Guide to the Sharks of the World. London : Collins 368 pp. 

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

    IUCN SSC Shark Specialist Group. Specialist Group website. Available at:

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

    Liu, K.-M., Changa, Y.-T., Ni, I.-H. & Jin, C.-B. 2006. Spawning per recruit analysis of the pelagic thresher shark, Alopias pelagicus, in the eastern Taiwan waters. Fisheries Research 82: 52-64.

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    Nakamura, H. 1935. On the two species of the thresher shark from Formosan waters. Memoirs of the Faculty of Science and Agriculture, Taihoku Imperial University 14(1): 1-6 figs 1-3.

    Oliver SP, Turner JR, Gann K, Silvosa M, D'Urban Jackson T (2013) Thresher Sharks Use Tail-Slaps as a Hunting Strategy. PLoS ONE 8(7): e67380. doi:10.1371/journal.pone.0067380 PDF

    Otake, T. & Mizue, K. 1981. Direct evidence for oophagy in thresher shark, Alopias pelagicus. Japanese Journal of Ichthyology 28(2): 171-172.

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    Randall, J.E., Allen, G.R. & Steene, R. 1990. Fishes of the Great Barrier Reef and Coral Sea. Bathurst : Crawford House Press 507 pp. figs

    Reardon, M., Márquez, F., Trejo, T. & Clarke, S.C. 2009. Alopias pelagicus. In: IUCN 2012. IUCN Red List of Threatened Species. Version 2012.1. <>. Downloaded on 27 June 2012.

    Trejo, T. 2004. Global population structure of thresher sharks (Alopias spp.) based upon mitochondrial DNA control region sequences. M.Sc. Thesis, Moss Landing Marine Laboratories.

    Quick Facts

    CAAB Code:37012003


    Conservation:IUCN Vulnerable

    Danger:Thrashing tail, sharp teeth

    Depth:0-350 m

    Habitat:Oceanic, pelagic

    Max Size:3.65 m

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