Bigeye Tuna, Thunnus obesus (Lowe 1839)


Other Names: Bigeye, Big-eye Tuna

Part of a large school of Bigeye Tuna, Thunnus obesus, off Barwon Heads, Victoria, March 2017. Source: Rebecca Lloyd / iNaturalist.org. License: CC by Attribution-NonCommercial

Summary:

A large commercially important species found worldwide in tropical and subtropical oceanic waters. This is one of the largest tuna species, growing to a length of more than 230 cm and a weight of almost 200 kg.


Cite this page as:
Dianne J. Bray & Sascha Schultz, Thunnus obesus in Fishes of Australia, accessed 16 Sep 2019, http://fishesofaustralia.net.au/home/species/733

Bigeye Tuna, Thunnus obesus (Lowe 1839)

More Info


Distribution

Found worldwide in all tropical and sub-tropical waters, except the Mediterranean Sea. In Australia restricted to the northern half of the coastline, from the Recherche Archipelago, Western Australia, to about Cape Howe, Victoria. 

Bigeye Tuna are a highly migratory species found in the epi- and mesopelagic zones of the ocean from surface waters to a depth of 250 m. Juveniles and smaller adult fish usually school at or near the surface in groups of mixed sizes, or with other species, whereas larger adults are found in deeper water.

Although the preferred surface water temperate range is between 17°C and 22°C, data from commercial longline catches has shown that the species occurs at a wide range of water temperatures (13-29°C).  near ocean features such as current fronts, floating objects and thermoclines.


Features

Meristic features: Dorsal fin XI-XIV, 12-16; Analfin 11-16; Pectoral fin 30-36; Gill rakers 23-31; Vertebrae 39.

Body fusiform, elongate and slightly compressed, deepest at midle of spinous dorsal fin; caudal peduncle with a well-developed keel, flanked on each side by a smaller keel. Spinous and soft dorsal fins separated by a narrow space. Both dorsal and anal fins are followed by 7-10 finlets. Pectoral fins moderately long, 22-31%  fork length. Each jaw with a single series of small, conical teeth. Body covered in small scales, anterior corselet of larger scales indistinct. Swimbladder present.

Size

To at least 230 cm and 197 kg.

Colour

Bigeye Tuna are a metallic blue on top, whitish on the lower sides and belly, with no dark spots or stripes. The dorsal and anal fins are yellow,  and the finlets are bright yellow with a black margin. Live fish have an iridescent blue lateral band running along the sides.

Feeding

Bigeye Tuna are opportunistic predators, feeding on a range of fishes, squid and crustaceans. Juveniles consume planktonic invertebrates, especially crustaceans such as copepods and cladocerans. 

Large adults often feed below the thermocline, even occasionally diving below 500 metres.

Biology

The sexes are separate and fertilisation is external. Eggs and larvae are pelagic. Spawning occurs a night on the full moon in tropical waters. Females spawn more than 2 million tiny pelagic eggs. The larvae and juveniles grow rapidly and mature during their second or third year between 100-130 cm in length. They grow to a maximum age of 16 years.

Conservation

IUCN: The species is listed as Vulnerable on the IUCN Red List of Threatened Species http://www.iucnredlist.org/apps/redlist/details/21859/0, and the Pacific stock is listed as Endangered on the IUCN Red List of Threatened Species http://www.iucnredlist.org/apps/redlist/details/21859/0

Species Citation

Thynnus obesus Lowe 1839, Proc. Zool. Soc. Lond. 7: 78, Madeira.

Author

Dianne J. Bray & Sascha Schultz

Bigeye Tuna, Thunnus obesus (Lowe 1839)

References


Block, B.A. & E.D. Stevens (eds). 2001. Tuna: Physiology, Ecology and Evolution (Fish Physiology Series, Vol.19) Academic Press, 464 p.

Boye, J., M. Musyl, R. Brill, and H. Malte. 2009. Transectional heat transfer in thermoregulating bigeye tuna (Thunnus obesus) - a two-dimensional heat flux model. J. Exp. Biol. 212: 3708 -3718.

Brill, R.W., K.A. Bigelow, M.K. Musyl, K.A. Fritsches, and E.J. Warrant. 2005. Bigeye tuna behavior and physiology... their relevance to stock assessments and fishery biology. Col. Vol. Sci. Pap. ICCAT 57: 142-161.

Campbell, R.A. (2005) Integrated Analysis and Assessment of the Eastern Tuna and Billfish Fishery - Compilation of Related Project Papers. Report to the Australian Fisheries Management Authority, Canberra.

Carpenter, K.E.; Niem, V.H. (eds). FAO species identification guide for fishery purposes. The living marine resources of the Western Central Pacific. Volume 6. Bony fishes part 4 Rome, FAO. 2001. pp. 3381-4218.

Collette, B.B. & C.E. Nauen, FAO species 1983, catalogue. Vol. 2. Scombrids of the world. An annotated and illustrated catalogue of tunas, mackerels, bonitos and related species known to date. FAO Fish.Synop., (125)Vol.. 2: 137 p. 

Evans, K., A. Langley, N.P. Clear, P. Williams, T. Patterson, J. Sibert, J. Hampton & J.S. Gunn. 2008. Behaviour and habitat preferences of bigeye tuna (Thunnus obesus) and their influence on longline fishery catches in the western Coral Sea. Can. J. Fish. Aquat. Sci. 65: 2427–2443.

Farley, J.H., N.P. Clear, B. Leroy, T.L.O. Davis & G. McPherson. 2006. Age, growth and preliminary estimates of maturity of bigeye tuna, Thunnus obesus, in the Australian region. Marine and Freshwater Research, 57: 713–724.

Galli, G., H. Shiels, and R. Brill.  2009.  Cardiac temperature sensitivity in yellowfin tuna (Thunnus albacares), bigeye tuna (T. obesus), mahimahi (Coryphaena hippurus) and swordfish (Xiphias gladius). Physiol.  and Biochem. Zool. 82: 280-290.

Hoese, D.F., D.J. Bray, J.R. Paxton, & G.R. Allen. 2006. Fishes. in Beesley, P.L. & A. Wells. (eds) Zoological Catalogue of Australia. Volume 35. ABRS & CSIRO Publishing: Australia. parts 1-3, pages 1-2178.

Holland, K.N., R.W. Brill, R.K.C. Chang, J.R. Sibert & D.A. Fournier. 1992. Physiological and behavioural thermoregulation in bigeye tuna (Thunnus obesus). Nature 358, 410 – 412.

 Uozumi, Y. 1996. Thunnus obesus. In: IUCN 2010. IUCN Red List of Threatened Species. Version 2010.4. <www.iucnredlist.org>.

Kalish J.M. (ed) (2004) The Southern and Western Tuna and Billfish Fishery 2004. Fishery Assessment Report compiled by the Southern and Western Tuna and Billfish Fishery Scientific Assessment Group. Australian Fisheries Management Authority, Canberra. 

Lowe, T., R. Brill, and K. Cousins. 2000. Blood O2-binding characteristics of bigeye tuna (Thunnus obesus), a high-energy-demand teleost that is tolerant of low ambient O2. Mar. Biol. 136: 1087-1098.

Malte, H., C. Larsen, M. K. Musyl, and R. W. Brill. 2007. Differential heating and cooling rates in bigeye tuna (Thunnus obesus); a model of non-steady state heat exchange. J. Exp. Biol. 210: 2618-2626.

Nikaido, H., N. Miyabe, and S. Ueyanagi. 1991. Spawning time and frequency of bigeye tuna, Thunnus obesus. Bull. Nat. Res. Inst. Far Seas Fish., 28:47-73.Swimmer, Y., L. McNaughton, C. Moyes, and R. Brill. 2005. Metabolic biochemistry of cardiac muscle in three tuna species (bigeye, Thunnus obesus; yellowfin, T. albacares; and skipjack, Katsuwonus pelamis) with divergent ambient temperature and oxygen tolerances. Fish Physiol. Biochem. 30: 27-25.

Sun, C.L., C.L. Huang, and S.Z. Yeh, 2001. Age and growth of the bigeye tuna Thunnus obesus in the western Pacific Ocean. U. S. Nat. Mar. Fish. Serv., Fish. Bull., 99: 502-509.

Uozumi, Y. 1996. Thunnus obesus. In: IUCN 2010. IUCN Red List of Threatened Species. Version 2010.4. <www.iucnredlist.org>.

Uozumi, Y. 1996. Thunnus obesus (Pacific stock). In: IUCN 2010. IUCN Red List of Threatened Species. Version 2010.4. <www.iucnredlist.org>.

Young, J.W. & T.L.O. Davis. 1990. Feeding ecology of larvae of southern bluefin, alabacore and skipjack tunas (Pisces: Scombridae) in the eastern Indian Ocean. Marine Ecology Progress Series, 61: 17-29.

Quick Facts


CAAB Code:37441011

Conservation:IUCN Vulnerable

Depth:0-200+ m

Fishing:Commercial, recreational

Habitat:Pelagic, oceanic

Max Size:230 cm TL, 200 kg

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Species Maps

CAAB distribution map