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Thunnus obesus (Lowe, 1839)

Bigeye tuna
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Native range | All suitable habitat | Point map | Year 2050
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Thunnus obesus   AquaMaps   Data sources: GBIF OBIS
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Image of Thunnus obesus (Bigeye tuna)
Thunnus obesus
Picture by Chow, S.


United States (contiguous states) country information

Common names: Ahi, Ahi po'onui, Bigeye tuna
Occurrence: native
Salinity: marine
Abundance: | Ref:
Importance: minor commercial | Ref: FAO, 1994
Aquaculture: | Ref:
Regulations: | Ref:
Uses: no uses
Comments:
National Checklist:
Country Information: https://www.cia.gov/library/publications/resources/the-world-factbook/geos/us.html
National Fisheries Authority: http://www.nmfs.gov
Occurrences: Occurrences Point map
Main Ref: Collette, B.B. and C.E. Nauen, 1983
National Database:

Common names from other countries

Classification / Names Common names | Synonyms | Catalog of Fishes(genus, species) | ITIS | CoL | WoRMS | Cloffa

Teleostei (teleosts) > Scombriformes (Mackerels) > Scombridae (Mackerels, tunas, bonitos) > Scombrinae
Etymology: Thunnus: Greek, thynnos = tunna (Ref. 45335).
  More on author: Lowe.

Environment: milieu / climate zone / depth range / distribution range Ecology

Marine; pelagic-oceanic; oceanodromous (Ref. 51243); depth range 0 - 1500 m (Ref. 117020), usually 0 - 500 m (Ref. 117020).   Subtropical; 13°C - 29°C (Ref. 168); 52°N - 48°S, 180°W - 180°E

Distribution Countries | FAO areas | Ecosystems | Occurrences | Point map | Introductions | Faunafri

Atlantic, Indian and Pacific: in tropical and subtropical waters. Absent in the Mediterranean. Highly migratory species.

Length at first maturity / Size / Weight / Age

Maturity: Lm 112.5, range 100 - 125 cm
Max length : 250 cm TL male/unsexed; (Ref. 27000); common length : 180 cm FL male/unsexed; (Ref. 168); max. published weight: 210.0 kg (Ref. 9987); max. reported age: 11 years (Ref. 30326)

Short description Identification keys | Morphology | Morphometrics

Dorsal spines (total): 13 - 14; Dorsal soft rays (total): 14 - 15; Anal spines: 0; Anal soft rays: 14; Vertebrae: 39. This large species is distinguished by the following characters: robust, fusiform body, slightly compressed from side to side; total gill rakers on first gill arch 23-31; dorsal fins separated only by a narrow interspace, the second followed by 8-10 finlets; anal fin followed by 7-10 finlets; pectoral fins moderately long (22 to 31% of fork length) in large specimens (over 110 cm FL), but very long (as long as in Thunnus alalunga) in smaller specimens; 2 flaps (interpelvic process) between pelvic fins; very small scales on body; corselet of larger and thicker scales developed, but not very distinct; caudal peduncle very slender, with a strong lateral keel between 2 smaller keels; ventral surface of liver striated; swimbladder present. Colour of back metallic dark blue, lower sides and belly whitish; a lateral iridescent blue band runs along sides in live specimens; first dorsal fin deep yellow, second dorsal and anal fins light yellow, finlets bright yellow edged with black (Ref. 9684).

Biology     Glossary (e.g. epibenthic)

Occur in areas where water temperatures range from 13°-29°C, but the optimum is between 17° and 22°C. Variation in occurrence is closely related to seasonal and climatic changes in surface temperature and thermocline. Juveniles and small adults school at the surface in mono-species groups or mixed with other tunas, may be associated with floating objects. Adults stay in deeper waters (Ref. 5377). Eggs and larvae are pelagic (Ref. 6390). Feed on a wide variety of fishes, cephalopods and crustaceans during the day and at night (Ref. 9340). Meat is highly prized and processed into sashimi in Japan. Marketed mainly canned or frozen (Ref. 9684), but also sold fresh (Ref. 9340).

Life cycle and mating behavior Maturities | Reproduction | Spawnings | Egg(s) | Fecundities | Larvae

Are multiple spawners that may spawn every 1 or 2 days over several months (Ref. 30330). They spawn over periods of the full moon (Ref. 6390). Spawn throughout the year in tropical waters (Ref. 6390).

Main reference Upload your references | References | Coordinator : Collette, Bruce B. | Collaborators

Collette, B.B. and C.E. Nauen, 1983. FAO Species Catalogue. Vol. 2. Scombrids of the world. An annotated and illustrated catalogue of tunas, mackerels, bonitos and related species known to date. Rome: FAO. FAO Fish. Synop. 125(2):137 p. (Ref. 168)

IUCN Red List Status (Ref. 130435)

  Vulnerable (VU) (A2bd); Date assessed: 15 January 2021

CITES (Ref. 128078)

Not Evaluated

CMS (Ref. 116361)

Not Evaluated

Threat to humans

  Harmless




Human uses

Fisheries: highly commercial; gamefish: yes
FAO(Fisheries: production, species profile; publication : search) | FIRMS (Stock assessments) | FishSource | Sea Around Us

More information

Trophic ecology
Food items
Diet compositions
Food consumptions
Food rations
Predators
Ecology
Ecology
Home ranges
Life cycle
Reproduction
Maturities
Fecundities
Spawnings
Spawning aggregations
Egg(s)
Egg developments
Larvae
Larval dynamics
Anatomy
Gill areas
Brains
Otoliths
Physiology
Body compositions
Nutrients
Oxygen consumptions
Swimming type
Swimming speeds
Visual pigment(s)
Fish sounds
Diseases / Parasites
Toxicities (LC50s)
Genetics
Genetics
Electrophoreses
Heritabilities
Human related
Aquaculture systems
Aquaculture profiles
Strains
Ciguatera cases
Stamps, coins, misc.
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Estimates based on models

Preferred temperature (Ref. 115969): 16.8 - 28.6, mean 26.6 (based on 3638 cells).
Phylogenetic diversity index (Ref. 82804):  PD50 = 0.5039   [Uniqueness, from 0.5 = low to 2.0 = high].
Bayesian length-weight: a=0.01318 (0.01039 - 0.01673), b=3.03 (2.99 - 3.07), in cm Total Length, based on LWR estimates for this species (Ref. 93245).
Trophic level (Ref. 69278):  4.5   ±0.0 se; based on diet studies.
Resilience (Ref. 120179):  Medium, minimum population doubling time 1.4 - 4.4 years (K=0.11-0.23; tm=3; tmax=11; Fec=2 million).
Prior r = 0.52, 95% CL = 0.34 - 0.77, Based on 10 full stock assessments.
Fishing Vulnerability (Ref. 59153):  High vulnerability (56 of 100).
Climate Vulnerability (Ref. 125649):  Moderate to high vulnerability (47 of 100).
Price category (Ref. 80766):   Very high.