Thunnus alalunga | fishIDER

Characteristic features:

Colour:

Dark blue-black above edged with a narrow iridescent blue band in fresh specimens. Silver flanks and belly. First dorsal fin yellow, second dorsal and anal fins light yellow. Anal finlets dark, caudal fin with white posterior margin.

Size:

Up to 120 cm TL and 60.3 kg in weight.

Distribution:

Found in subtropical waters circumglobally.

View FAO distribution map

Habitat:

Pelagic and oceanic. Found in temperatures ranging between 9.5–25.2 °C and found at depths from the surface to 600 m.¹

Biology:

Feeds on fishes, squids and crustaceans. Forms large schools with similarly sized tuna such as Skipjack (Katsuwonus pelamis), Yellowfin tuna (Thunnus albacares), and Southern bluefin tuna (Thunnus maccoyii). Length at maturity is 90–94 cm FL for females and 94–97 cm FL for males². Age of first maturity is estimated to be between 5–7 years. ³ Spawning occurs in waters with a sea surface temperature of at least 24 °C. Albacore tuna are batch spawners and spawn at least twice per season. A female of 20 kg can produce between 2–3 million eggs per spawning period.² Maximum age is estimated to be at least 13 years.⁴

Indonesian fisheries:

Caught by long lining, purse seining and by trolling.

Similar species:

Thunnus albacares
Yellowfin tuna

Thunnus albacares differs in having moderately long pectoral fins not reaching posterior of second dorsal fin base (vs. very long, extending to second dorsal finlet); a series of white/silver body markings in regularly spaced, vertical lines and alternating lines of spots in a ‘chevron’ pattern (vs. white/silver body markings as horizontal to oblique, broken lines in stressed live, and freshly dead specimens only, otherwise no markings); caudal fin yellowish/silver (vs. dark with white posterior margin); ventral surface of liver smooth, right lobe elongated (vs. striated, lobes roughly equal in length) and 26–34 gill rakers on first gill arch (vs. 25–31).

to Thunnus albacares

Thunnus maccoyii
Southern bluefin tuna

Thunnus maccoyii differs in having short pectoral fins, never reaching interdorsal space (vs. very long, extending to second dorsal finlet); white/silver body markings as vertical, irregularly spaced, often broken or incomplete lines present in stressed live specimens only (vs. white/silver horizontal to oblique, incomplete stripes present in stressed live, and freshly dead specimens only); 31–34 gill rakers on first gill arch (vs. 25–31) and a yellow median keel in adults (vs. dark).

to Thunnus maccoyii

Thunnus obesus
Bigeye tuna

Thunnus obesus differs in having a greater head length and depth (vs. smaller) larger eye diameter (vs. smaller) for a given FL; body deep and rounded (vs. slender and elongate); pectoral fins very long, tips tapering to a thin flexible, point (in adults) (vs. very long, tips bluntly rounded) and white/silver body markings as irregularly spaced, vertical, sometimes broken lines (vs. white/silver horizontal to oblique, incomplete stripes present in stressed live, and freshly dead specimens only).

to Thunnus obesus

Thunnus orientalis
Pacific bluefin tuna

Thunnus orientalis differs in having short pectoral fins never reaching interdorsal space (vs. very long, extending to second dorsal finlet); and white/silver body markings as vertical lines and alternating lines of spots (vs. white/silver horizontal to oblique, incomplete stripes present in stressed live, and freshly dead specimens only).

to Thunnus orientalis

Thunnus tonggol
Longtail tuna

Thunnus tonggol differs in having pectoral fins moderate in length, not reaching beyond second dorsal-fin base (vs. very long, extending to second dorsal finlet); posterior portion of body (from deepest point to caudal peduncle) long relative to FL (vs. moderate); body markings as horizontal rows of white/silver elongate spots on belly (vs. white/silver horizontal to oblique, incomplete stripes present in stressed live, and freshly dead specimens only); ventral surface of liver smooth with elongated right lobe (vs. striated, lobes roughly equal in length) and 19–27 (usually 26 or less) gill rakers on first gill arch (vs. 25–31).

to Thunnus tonggol

Thunnus alalunga gallery
Thunnus alalunga quiz

FishBase
The IUCN Red List of Threatened Species^TM

References:

Collette BB, Nauen CE. FAO species catalogue. Volume 2. Scombrids of the world. An annotated and illustrated catalogue of tunas, mackerels, bonitos and related species known to date. 1983.
Collette BB, Cole K. Reproduction and development in epipelagic fishes. Reproduction and sexuality in marine fishes: patterns and processes University of California Press, Berkeley. 2010;21–63.
Ramón D, Bailey K. Spawning seasonality of albacore, Thunnus alalunga, in the South Pacific Ocean. Fishery Bulletin. 1996;94(4):724–33.
Lee L-K, Yeh S-Y. Age and growth of South Atlantic albacore–a revision after the revelation of otolith daily ring counts. Collect Vol Sci Pap ICCAT. 2007;60(2):443–56.