Actinopterygii (ray-finned fishes) > Perciformes
(Perch-likes) > Scombridae
(Mackerels, tunas, bonitos) > Scombrinae
Etymology: Auxis: Greek, auxis = a variety of tunna (Ref. 45335).
Issue on validity of subspecies: subspecies considered as valid in FB, elevated to species rank as Auxis rochei (Risso, 1810) in Eschmeyer (CofF ver. Mar. 2011: Ref. 86697). Please send references, or more studies are needed.
Environment / Climate / Range
Marine; brackish; pelagic-neritic; oceanodromous (Ref. 51243); depth range 10 - ? m (Ref. 9340). Tropical; ? - 28°C (Ref. 168); 61°N - 51°S, 180°W - 180°E
Length at first maturity / Size / Weight / Age
Maturity: Lm ?, range 35 - ? cm
Max length : 50.0 cm FL male/unsexed; (Ref. 168)
(total): 9 - 12;
soft rays: 12 - 14. Back bluish, turning to deep purple or almost black on head. Scaleless area with pattern of 15 or more fairly broad, nearly vertical dark bars. 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, not reaching vertical line from anterior margin of scaleless area above corselet. A large, single-pointed flap (interpelvic process) between pelvic fins. Body naked except for corselet, which is well developed in its posterior part 9 more than 6 scales wide under second dorsal-fin origin). A strong central keel on each side of caudal-fin base between 2 smaller keels (Ref 9684).
Atlantic, Indian and Pacific: including the Mediterranean Sea. The eastern Pacific population is recognized as subspecies Auxis rochei eudorax (Ref. 32349). Highly migratory species, Annex I of the 1982 Convention on the Law of the Sea (Ref. 26139).
Adults are principally caught in coastal waters and around islands (Ref. 9340). Form schools. Feed on small fishes, particularly anchovies, crustaceans (especially crab and stomatopod larvae) and squids. Eggs and larvae are pelagic (Ref. 6769). Because of their abundance, they are considered an important element of the food web, particularly as forage for other species of commercial interest. Also caught with encircling nets and troll lines (Ref. 9340). Marketed fresh and frozen (Ref. 9340) and also dried or salted, smoked and canned (Ref. 9987).
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. 94:423-441.
IUCN Red List Status (Ref. 90363)
Threat to humans
Fisheries: highly commercial; gamefish: yes
Estimates of some properties based on empirical models
Phylogenetic diversity index (Ref. 82805
= 0.7500 [Uniqueness, from 0.5 = low to 2.0 = high].
Bayesian length-weight: a=0.01081 (-0.02299 - 0.04461), b=3.08 (3.06 - 3.10), based on LWR estimates for this species (Ref. 93245
Trophic Level (Ref. 69278
): 4.1 ±0.6 se; Based on diet studies.
Resilience (Ref. 69278
): Medium, minimum population doubling time 1.4 - 4.4 years (K=0.32; tm=2; Fec=31,000-103,000).
Vulnerability (Ref. 59153
): Low to moderate vulnerability (34 of 100) .