Actinopterygii (ray-finned fishes) > Perciformes
(Perch-likes) > Scombridae
(Mackerels, tunas, bonitos) > Scombrinae
Etymology: Auxis: Greek, auxis = a variety of tunna (Ref. 45335).
Environment / Climate / Range
Marine; pelagic-neritic; oceanodromous (Ref. 51243); depth range 50 - ? m (Ref. 9340). Tropical; 27°C - 28°C, preferred 27°C (Ref. 107945); 61°N - 51°S, 180°W - 180°E
Atlantic, Indian and Pacific (Western Central). Eastern Pacific population recognized as subspecies Auxis thazard brachydorax (Ref. 32349).
Many authors have used the name Auxis thazard as including Auxis rochei in the belief that there was only a single worldwide species of Auxis. Highly migratory species, Annex I of the 1982 Convention on the Law of the Sea (Ref. 26139).
Length at first maturity / Size / Weight / Age
Maturity: Lm 30.0, range 29 - ? cm
Max length : 65.0 cm FL male/unsexed; (Ref. 29114); common length : 60.0 cm TL male/unsexed; (Ref. 47377); max. published weight: 1.7 kg (Ref. 40637); max. reported age: 5 years (Ref. 29114)
(total): 10 - 12;
soft rays: 10 - 14. Back bluish, turning to deep purple or almost black on the head. A pattern of 15 or more narrow, oblique to nearly horizontal, dark wavy lines in scaleless area above lateral line. Belly white. Pectoral and pelvic fins purple, their inner sides black. Body robust, elongate and rounded. Teeth small and conical, in a single series. Pectoral fins short, but reaching past vertical line from anterior margin of scaleless area above corselet. A large single-pointed flap (interpelvic process) between pelvic fins. Body naked except for the corselet, which is well developed and narrow in its posterior part (no more than 5 scales wide under second dorsal-fin origin). A strong central keel on each side of caudal-fin base between 2 smaller keels (Ref 9684).
Epipelagic in neritic and oceanic waters (Ref. 9340). Feeds on small fish, squids, planktonic crustaceans (megalops), and stomatopod larvae (Ref. 5213). Because of their abundance, they are considered an important element of the food web, particularly as forage for other species of commercial interest. Preyed upon by larger fishes, including other tunas (Ref. 9987). Marketed fresh and frozen (Ref. 9340); also utilized dried or salted, smoked and canned (Ref. 9987).
In correlation with temperature and other environmental changes, the spawning season varies with areas, but in some places it may even extend throughout the year.
Collette, B.B. and C.R. Aadland, 1996. Revision of the frigate tunas (Scombridae, Auxis), with descriptions of two new subspecies from the eastern Pacific. Fish. Bull. 94(3):423-441. (Ref. 32349)
IUCN Red List Status (Ref. 109396)
CITES (Ref. 94142)
Threat to humans
Fisheries: highly commercial; gamefish: yes
Estimates of some properties based on models
Phylogenetic diversity index (Ref. 82805
= 0.5625 [Uniqueness, from 0.5 = low to 2.0 = high].
Bayesian length-weight: a=0.00933 (0.00787 - 0.01107), b=3.06 (3.02 - 3.10), based on LWR estimates for this species (Ref. 93245
Trophic Level (Ref. 69278
): 4.4 ±0.4 se; Based on diet studies.
Resilience (Ref. 69278
): Medium, minimum population doubling time 1.4 - 4.4 years (K=0.8; tmax=5; Fec=200,000 to >1 million).
Prior r = 0.93, 2 SD range = 0.52 - 1.68, log(r) = -0.07, SD log(r) = 0.29, Based on: 2 M, 11 K, 4 tmax, 3 Fec records
Vulnerability (Ref. 59153
): Low vulnerability (25 of 100) .