spent gonads were taken in June-July and July-August, 

 respectively (Suzuki and Morio 1957). This was con- 

 firmed by Hamada, Morita, Ishida, and Takezawa 

 (1973), who examined the gonad condition factors of A. 

 rochei caught in waters off Kochi Prefecture and sug- 

 gested that spawning took place in late June. They also 

 examined the gonad condition of A. rochei taken off 

 Taiwan in June-July and found that the gonad index 

 was very high indicating perhaps that spawning was im- 

 minent. Concerning the larvae, Yabe and Ueyanagi 

 (1962) collected those of A. rochei from May through 

 July near Japan whereas Yokota et al. (1961) obtained 

 larval A. rochei, measuring 3-5 mm TL (total length), 

 from south of Shikoku and Kyushu in June-August but 

 most were taken in July. Farther south, however, in the 

 Celebes and South China Seas, larval A. rochei were col- 

 lected predominantly during January and February 

 (Yabe and Ueyanagi 1962). 



It has also been established that Auxis spawn in the 

 Indian Ocean (Bogorov and Rass 1961) and that spawn- 

 ing extends for at least 8 months from August to April; 

 however, there is no information on their spawning ac- 

 tivity for the rest of the year. Among the tuna larvae col- 

 lected by the Dana Expedition from south of the equator 

 between lat. 3° and 24°S at long. 50°E, Jones and 

 Kumaran (1963) found 131 larval A. thazard, indicat- 

 ing that this species spawned in this area in December- 

 January. North of the equator in the Laccadive Sea, 

 they also found larval A. thazard in the samples indi- 

 cating a spawning period in January-April, slightly later 

 in the year than in the south. Rao (1964) added that 

 among samples of A. thazard he collected from commer- 

 cial landings, the percentage of maturing and mature 

 ovaries was highest in March. In August and 

 September, the majority of the fishes examined were ac- 

 tually in spawning condition and some individuals com- 

 pletely spent. Samples obtained subsequently in 

 November contained only spent fish. 



Although evidence indicates that A. thazard spawn in 

 the Indian Ocean, present data concerning spawning of 

 A. rochei are still too meager to draw definite conclu- 

 sions. Jones and Kumaran (1%3) found 20 larval A. 

 rochei in the Dana collection from the Indian Ocean. All 

 were collected in December-January from three loca- 

 tions between Madagascar and the African coast. Mat- 

 sumoto (1959), who examined the collection made by 

 the Dana from the eastern Indian Ocean southwest of 

 the Sunda Archipelago in August-November, recog- 

 nized the presence of two types of Auxis larvae. Gor- 

 bunova (1963) confirmed Matsumoto's observations, 

 reporting that two types of Auxis larvae were distin- 

 guished in the Soviet collection made in the Indian 

 Ocean. From the information available, Jones and 

 Kumaran (1963) hypothesized that low latitudinal areas 

 of the eastern Indian Ocean southwest of the Sunda 

 Archipelago and the western Indian Ocean between 

 Madagascar and the coast of Africa are possible spawn- 

 ing grounds of A. rochei. Gorbunova (1965a, 1965c) col- 

 lected A. thazard larvae of 5-11 mm in February and 

 March in the Bay of Bengal. 



In the Atlantic Ocean, tuna larvae have been col- 

 lected off the west coast of Africa, mainly in the region of 

 Dakar at the western tip of Africa, and off Takoradi in 

 the Gulf of Guinea (Kazanova 1962; Richards 1969). 

 Among the various species of larval tuna and tunalike 

 fishes collected, those identified as Auxis were most 

 numerous. Kazanova had at his disposal a series of 

 Auxis larvae some as small as 3 mm. Furthermore, in 

 addition to larvae identified as ^4. thazard, there were 

 others which were similar to A. thazard but differing in 

 some characteristics. Kazanova referred to them as the 

 second of the two groups (Type II of Matsumoto 1959) of 

 Auxis larvae. Therefore, it can be inferred that these 

 regions of the Atlantic are also spawning grounds of the 

 two species of Auxis. 



Certain areas in the Mediterranean Sea have also 

 been suggested as possible spawning sites of Auxis sp. 

 Ehrenbaum (1924) reported Auxis spawning from July 

 to September in the Mediterranean. Off Greece, spawn- 

 ing of Auxis was also reported to occur from June to 

 September and in the Gulf of Catania (Sicily) in June 

 and July (Belloc 1954). Declerc et al. (1973) reported 

 capturing recently hatched larvae of Auxis in waters 

 surrounding the Balearic Islands, located off the 

 Mediterranean Spanish coast. In August-September 

 1971, 140 larval Auxis were captured by the RV Ichthys 

 and in June-July 1972, an additional 52 Auxis larvae 

 were taken. According to the authors, larval Auxis was 

 the most abundant among the tuna larvae captured 

 which included Thunnus thynnus, T. alalunga, and 

 Sarda sp. The presence of the planktonic stages of all 

 these tuna species in the plankton-net catches provided 

 evidence that these species spawned in waters near the 

 Balearic Islands. 



The waters around Tunisia have yielded Auxis in a 

 mature state, and this bit of evidence has led Postel 

 (1964) to believe that spawning probably takes place in 

 Tunisian waters. Postel examined the gonads of Auxis 

 caught in madragues (traps) off Tunisia, found them 

 mature, and concluded that spawning occurs in June- 

 August. For Auxis that were taken off Algeria, Postel 

 also determined that they spawn there probably in 

 August. Off the northwestern coast of Africa, Cape 

 Verde Islands and Dakar have been mentioned as 

 spawning sites of Auxis (Frade and Postel 1955; 

 Kazanova 1962). Gorbunova (1965c) reported capturing 

 about 6(X) Auxis larvae at one station in the Gulf of 

 Aden. 



In the western Atlantic, the Gulf of Mexico appears to 

 be a large spawning ground for Auxis. Hayasi (1972) 

 reported collecting tuna larvae identified as yellowfin, 

 bigeye, skipjack, and Auxis in gulf waters (Fig. 17). 

 Klawe and Shimada (1959), who collected juvenile 

 Auxis in March-April and in June-August from a large 

 number of stations spread widely over the Gulf of Mex- 

 ico, stated that the north central gulf region is definitely 

 a spawning locality for this species. The area southeast 

 of the Mississippi River Delta is another possible spawn- 

 ing site because most of the larvae were captured there, 

 but Klawe and Shimada pointed out that the collection 



21 



