Longtail Tuna, Thunnus tonggol (Bleeker 1851)


Other Names: Bluefin Tuna, Northern Bluefin Tuna, Northern Blue-finned Tuna

Longtail Tuna, Thunnus tonggol. Source: Australian National Fish Collection, CSIRO. License: CC BY Attribution-Noncommercial

Summary:

Longtail Tuna is a relatively small slender species with a very long slender tail and elongate oval spots in rows on the underside and belly. This highly prized sports fish cannot be targeted by commercial fisheries in Australia. In the past, Longtail Tuna have been incorrectly called northern bluefin tuna.


Cite this page as:
Dianne J Bray & Sascha Schultz, Thunnus tonggol in Fishes of Australia, accessed 17 Nov 2018, http://fishesofaustralia.net.au/home/species/734

Longtail Tuna, Thunnus tonggol (Bleeker 1851)

More Info


Distribution

Known from tropical to temperate waters of the Red Sea and Indo-west Pacific, from East Africa, east to New Guinea, north to southern Japan and south to Australia. In Australia, Longtail Tuna are usually common in coastal waters of northern Australia, migrating southwards during summer months; known from Fremantle, WA, to Twofold Bay, NSW, and absent from the southern coast. Epipelagic on the continental shelf. Although prefering inshore waters, Longtail Tuna avoid estuaries and murky waters. They form schools of different age classes and often school with other tuna species. 

Features

Meristics: D XI-XIV, 12-16; A 11-16; P 30-36.

Morphology: Body fusiform, elongate and slightly compressed.  Caudal peduncle with well-developed keel, flanked on each side by a smaller keel. Dorsal fins separated by a narrow space. Second dorsal and anal fins each followed by 7-10 finlets. Pectoral fins moderately long, ranging from 22-31% of fork length in fish under 60 cm fork length, and 16-22% in larger fish. Small, conical teeth forming a single series. Body covered in small scales, anterior corselet of larger scales indistinct. Swimbladder absent or very poorly developed.

Size

Longtail Tuna grows to a total length of 142 cm and weight of 35.6 kg.

Colour

Longtail Tuna have a typical countershading colour pattern. They are a metallic dark blue to black on the upper third of the body, and silver-white below, with colourless elongate oval spots in rows along the underside and belly.

Feeding

Longtail Tuna are opportunistic predators, feeding on a wide variety of prey, including fishes, squid and crustaceans. They feed mostly during daylight hours, prefering small pelagic fishes like anchovies and sardines, larger individuals may prey on larger and faster swimming fishes, such as mackeral, garfish, scads and flying fishes.

Biology

Longtail Tuna reach maturity at about 60-70 cm in length. The sexes are separate and fertilisation is external. Females mature at 40 cm fork length, and have a long spawning season from September to March in warmer waters with temperatures above 24° C. They produce between 1.2 and 1.9 million eggs per spawning event. The eggs and larvae are pelagic.

Fisheries

Throughout their range, Longtail Tuna are targeted mostly in small coastal fisheries, especially in Indonesia, Iran, Malaysia and Thailand, where much of the product is canned for worldwide sale. They are caught by purse-seine, gillnet and trolling, and may also be taken as bycatch in longline fisheries. 

Longtail Tuna are also an important and highly prized recreational fish and the flesh is reported to have a medium texture with a rich flavour. In 2006, Longtail Tuna were declared a "Recreational only" species by the Australian Federal Government. The species is managed by the Australian Fisheries Management Authority (AFMA) and annual bycatch limits have been imposed on Commonwealth Managed fisheries. Recreational fishes must abide by the size and bag limits set by the various state fisheries agencies. The first large-scale survey of Longtail Tuna catches in Australian waters is currently being undertaken. http://www.longtailtuna.com.au/Home.aspx

Conservation

Not evaluated.

Remarks

Unlike all other species in the genus Thunnus ('true" tunas), Longtail Tuna are unique in either lacking, or in having a very rudimentary swim bladder.

Species Citation

Thynnus tonggol Bleeker 1851, Natuurkundig Tijdschrift voor Nederlandsch Indië v. 1: 356, Batavia.

Author

Dianne J Bray & Sascha Schultz

Longtail Tuna, Thunnus tonggol (Bleeker 1851)

References


Allen, G R. 1997. Marine fishes of tropical Australia and south-east Asia. Western Australian Museum, Perth. 1-292.

Allen, G.R.  & R. Swainston.  1988. The marine fishes of north-western Australia. A field guide for anglers and divers. Western Australian Museum, Perth. 201 p.

Bleeker, P. 1851. Over eenige nieuwe geslachten en soorten van Makreelachtige visschen van den Indischen Archipel. Natuurkundig Tijdschrift voor Nederlandsch Indië 1: 341-372. 

Boeseman, M. 1964. Scombroid types in the Leiden Museum collections. In Symposium on scombroid fishes part I. Marine Biological Association of India Symposium Series. 1(1): 462-468, Pls. 1-5 (figs. 1-19).

Chow , S., T. Nakagawa, N. Suzuki , H. Takeyama & T. Matsunaga. 2006. Phylogenetic relationships among Thunnus species inferred from rDNA ITS1 sequence. Journal of Fish Biology 68(Supplement A): 24–35.

Collette, B. B. 2001. Family Scombridae. pp. 3721-3756. In 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.

Collette, B.B.  2003. Family Scombridae Rafinesque 1815 – mackerels, tunas, and bonitos. California Academy of Sciences Annotated Checklists of Fishes No. 19: 1-28.

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

Collette, B.B., Reeb, C. & Block, B.A. 2001. Systematics of the tunas and mackerels (Scombridae). pp. 1–33. In Block, B.A. & Stevens, E.D. (eds) Tuna physiology, ecology and evolution. San Diego, CA: Academic Press.

Griffiths, S.P., Fry, G.C., Manson, F.J. & Lou, D.C. 2009. Age and growth of longtail tuna, Thunnus tonggol, in tropical and temperate waters of the central Indo-Pacific region. ICES Journal of Marine Science 67(1): 125-134.

Griffiths, S.P., G.C. Fry, F.J. Manson & R.D. Pillan. 2007. Feeding dynamics, consumption rates and daily ration of longtail tuna (Thunnus tonggol) in Australian waters, with emphasis on the consumption of commercially important prawns. Marine and Freshwater Research 58: 376-397.

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.

Korsmeyer, K.E. & H. Dewar. 2001. Tuna metabolism and energetics. pp. 35–78. In Block, B.A. & E.D. Stevens (eds.) Tuna physiology, ecology and evolution. Academic Press, San Diego.

Peters-Mason, A. 2010. Seafood Watch Report: Tongol tuna Thunnus tonggol. Monterey Bay Aquarium Seafood Watch Program. http://www.montereybayaquarium.org/cr/cr_seafoodwatch/content/media/MBA_SeafoodWatch_TongolTunaReport.pdf

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

Schaefer, K.R. 2001. Reproductive biology of tunas. pp. 225–270. In Block, B.A. & Stevens, E.D. (eds) Tuna physiology, ecology and evolution. pp. 1–33. San Diego, CA: Academic Press.

Ward, R. D. 1995. Population genetics of tunas. Journal of Fish Biology 47: 259–280.

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CAAB Code:37441013

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