Auxis rochei (Risso 1810)

Pectoral fins short, not reaching vertical line from anterior margin of scaleless area above corselet; corselet well developed in its posterior part (more than 6 scales wide, usually 10 to 15) under second dorsal fin origin). Colour: a pattern of 15 or more fairly broad, nearly vertical dark bars in the scaleless area.

Cosmopolitan in warm waters. See distribution map in generic section.

Maximum fork length is 50 cm in Japanese catches, common to 35 cm. Common fork lengths in the Indian Ocean range between 15 and 25 cm (Silas & Pillai, 1982). Fork length at first maturity off Gibraltar is 35 cm in females and 36.5 cm in males (Rodriguez-Roda, 1966).

An epipelagic, neritic as well as oceanic species. The spawning season may vary from region to region depending on the hydrographical regime: in many parts of the Mediterranean and in the Straits of Gibraltar, maturing fish are common from May onwards, and more than 30% are spent by September. In large areas of the Gulf of Mexico, peaks of batch spawning are reported from March to April and from June to August, while in the coastal waters from Cape Hatteras to Cuba and in the Straits of Florida, the spawning season begins in February. Indirect evidence suggests that the season extends at least from June through July off Taiwan Island and from May through August off southern Japan as indicated by gonad indexes and larval counts respectively. Silas (1969) estimated fecundity as ranging between 31 000 and 103 000 eggs per spawning according to the size of the fish. Food consists largely of small fishes, particularly anchovies and other clupeoids (Etchevers, 1957). For other pertinent information on the biology see generic section on Auxis .

Catches of Auxis are usually not identified to species. However, almost the entire Atlantic and Mediterranean catch is supposedly A. rochei . Between 1977 and 1981, 14 countries reported catches of Auxis from Fishing Areas 21, 27, 31, 34 and 47. The highest catches were reported by Ghana, Italy, Spain and Venezuela (FAO, 1983). The total catch in 1999 (Auxis rochei and Auxis thazard ) was 316 t, mainly Turkey 316 t.