428 



Fishery Bulletin 94|3), 1996 



Table 1 



Number of corselet scales under second dorsal-fin origin in populations of Auxis 



12 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 



A. t. thazard 



W. Atlantic 

 E. Atlantic 

 Indian O. 

 W. Pacific 



(' Pacific 



4 1 2 

 1 2 10 1 2 — 

 1 3 23 7 - 

 14 7 25 5 2 - 

 11 3 2 — 



A. t. brachydorax 



E. Pacific 13 8 42 2 3 - 



Galapagos 11 — 111 



A. r. rochei 



W. Atlantic 

 Mediterranean 

 E. Atlantic 

 Indian O. 

 W. Pacific 



A. r. eudorax 



E. Pacific 



2 8 4 7 4 1 -- 4 - 



3 2 1 5 1 1 



43 2 2966344 3 3212 



1 3 2 3 1 



1 — 10 1 7 366 1 1 - 1 - 



12 111 



3 2 2 3 



7 4.0 



14 2.9 



34 3 1 



53 2.5 



16 3.4 



124 2.7 



68 2.6 

 5 5.6 



73 2.8 



30 7.9 



13 9.2 



55 14.3 



10 11.5 



37 12.6 



148 11.7 



1 1 1 29 21.6 



narrow, oblique to nearly horizontal, dark wavy lines 

 in the scaleless area above the lateral line (Figs. 1 

 and 6). Spots sometimes occur between the pectoral 

 and pelvic fins (see Robins and Ray, 1986: pi. 48), as 

 they usually do in Euthynnus. 



Geographical distribution Probably cosmopolitan 

 in warm waters (Fig. 7) but there have been rela- 

 tively few documented occurrences in the Atlantic 

 Ocean. Although we did not examine specimens of 

 either species from the southeastern Atlantic and 

 although Zavalla-Camin (1983) concluded that there 

 was only a single variable species, both species do 

 occur there as can be seen from the anterior extent 

 of the dorsal scaleless area (Fig. 8, 20 specimens of 

 A. thazard and 33 specimens of A. rochei). On the 

 basis of two specimens of A. thazard from Haifa, Is- 

 rael (HUJ 17480, HUJ 17826) provided by Dani 

 Golani, we believe both species occur in the Mediter- 

 ranean Sea. 



Habitat and biology (From literature summarized 

 in Uchida, 1981, and Collette and Nauen, 1983:29.) 

 An epipelagic, neritic, and oceanic species. In the 

 eastern Pacific, mature fish occur throughout the 



30 



in 



in 



-20 



-30 



• Auxis rochei 

 O Auxis [hazard 



OO 



OO 





100 150 200 250 300 350 400 450 500 



Fork length (mm) 



Figure 5 



Distance from the tip of the pectoral fin (PI) to the bare 

 area above the lateral line in Auxis rochei (closed circles) 

 and A. thazard (open circles). 



