Collette and Aadland: Revision of the frigate tunas (Scombridae, Auxis) 



435 



name in a memo dated 1 Feb 1951 to W.I. Follett, 

 concerning an edition of their California fish list, with 

 copies to Fitch and Roedel. 



Material examined 73 specimens ( 205-400 mm FL) 

 from 29 collections. 



Holotype USNM 320406 (352 mm FL); 7°51'N, 

 99°51 W; Olympia; 16 Aug 1991. Pectoral fin 48.9 mm, 

 anterior extent of dorsal scaleless area 10.0 mm anterior 

 to tip of pectoral fin, width of corselet under second dor- 

 sal-fin origin 0.9 mm, 3 scales in corselet under second 

 dorsal-fin origin, gill rakers 10 + 35 = 45. See Fig. 9B. 



Paratypes from the eastern Pacific 48 specimens 

 (205-400 mm FL) from 21 collections. 



LACM 6711-2 (1, 335); CA, Orange Co., 1-2 mi off 

 Huntington Beach; 19 Sep 1960. LACM 34069-1 (1, 330); 

 CA, between Oceanside and San Clemente; 30 Sep 1972. 

 LACM 34254-1 (1, 379); CA, off San Onofre; 20 Jul 1974; 

 MV Bonanza. SIO 73-60 ( 1, 321 ); CA, La Jolla. SIO 60343 

 (1, 321); CA, San Diego, off Coronado Hotel. CAS 56979 

 (2, 355); Baja California, below Holcombe Point; 25 Jul 

 1958; IATTC. SIO 91-138 (10, 327-350); Baja California, 

 26°05N, 113°22 W; 12 Sep 1991; W. Mesa. LACM 34022-1 

 (1, 205); Baja California, Morgan Bank; Apr 1969; MV 

 Beverly Lynn; R. Chikami. LACM 6714-1 (10, 271-302); 

 Baja California, Morgan Bank. SIO 61-257 (2, 312-328); 

 Gulf of California, Ceralbo I., 24°08'N, 104°51.5'W; 22 Jun 

 1961; W. Baldwin. LACM 6708-1 (1, 335); Gulf of Califor- 

 nia, 450 Fathom Bank; 24 Mar 1950; MV Nancy Rose. CAS 

 56981 (3, 350-370); Mexico, Sinaloa, 30 mi off Mazatlan; 

 Apr 1951; MV Gaston Explorer; field number W 51-151. 

 ANSP 89064 ( 1, 363 ); Mexico, Tres Marias, Cleofa I.; 4 Jul 

 1941; Fifth Vanderbilt Expedition. LACM 6709-5 (2, 360- 

 372); 20°16'N, 105°59"W; 24 Nov 1951; R.C. Wilson 51-S- 

 87. ANSP 89066 (1, 350); Mexico, Colima, 18°00'N, 

 105°47 W; 29 Jun 1941; Fifth Vanderbilt Expedition. SIO 

 79-256 (2, 322-328); 15 Q 30'N, 93°30 W; 10 Apr 1974. LACM 

 6709-2 (1, 376); Gulf of Panama, 9°48'N, 86°00W; 13 Nov 

 1951; field number 51-S-82. SIO 80-172 (1, 342); 9°20N, 

 94°27W. LACM 6709-4 (1, 333); Gulf of Panama; field 

 number 51-S-85. USNM 334062 (3, 303-310); 7°51'N, 

 99°51W; Olympia; 16 Aug 1991. SIO 58-83-43A(2, 374- 

 395); Peru; 1958; Tomlinson. 



Other material examined 26 specimens (305-385 

 mm FL) from 4 collections. 



LACM 6711-8 (4, 360-380); "California"; Jun^Iul 1951; 

 MV Courageous. LACM 6711-9 (4, 355-385); "California." 

 UMMZ 160954 (1, 375); "from Mexico"; 16 Sep 1927; L.E. 

 Herr and L.A. Walford. USNM 325223 ( 17, 305-341 ); east- 

 ern Pacific, exchange from LACM, no other data. 



Galapagos Islands 6 specimens (315-400 mm FL) 

 from 4 collections. 



LACM 6713-1 (3, 358-375); Isabella I., 5 mi south of 

 Point Cristobal; 8 Mar 1954; MV Mayflower; H. Clemens. 

 LACM 39622-1 (1, 385); Skipjack Bank, 01°11'N, 91°03 W; 

 7 Dec 1952; H. Clemens. ANSP 71417 ( 1, 315); Charles I.; 

 Feb 1957; South Pacific Expedition; G. Vanderbilt. CAS 

 56980 (1, 400); Galapagos; Dec 1951; MV Golden West; 

 Field Number W51-276. 



Auxis rochei (Risso, 1810) 



Bullet tuna 



Diagnosis Auxis rochei has a wider corselet under 

 the second dorsal-fin origin, 5 or more scales wide, 

 usually 7-15 (Table 1), and the anterior margin of 

 the scaleless area above the corselet does not reach 

 the tip of the pectoral fin (Fig. 1). Color pattern: 15 

 or more fairly broad, nearly vertical dark bars in the 

 scaleless area above the lateral line (Figs. 1 and 6). 



Geographical distribution Cosmopolitan in warm 

 waters (Fig. 7). Both species occur off southeastern 

 Brazil (see distribution of A. thazard). Most con- 

 firmed records of Auxis from the Mediterranean Sea 

 are A. rochei, with the exception of two specimens of 

 A. thazard from Haifa, Israel. 



Habitat and biology ( From literature summarized 

 in Uchida, 1981, and Collette and Nauen 1983:30.) 

 An epipelagic, neritic, and oceanic species. The 

 spawning season may vary regionally depending on 

 the hydrographical regime. In many parts of the 

 Mediterranean and in the Straits of Gibraltar, ma- 

 turing 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 re- 

 ported from March to April and from June to Au- 

 gust, whereas in 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 and from May through August off 

 southern Japan, as indicated by gonad indices and 

 larval counts, respectively. Fecundity ranges between 

 31,000 and 103,000 eggs per spawning according to 

 size of the fish. Food consists largely of small fishes, 

 particularly anchovies and other clupeids (Etchevers, 

 1976). 



Size Maximum fork length is 500 mm in Japanese 

 catches, commonly to 350 mm. Common fork lengths 

 in the Indian Ocean range between 150 and 250 mm. 

 Fork length at first maturity off Gibraltar is 350 mm 

 for females and 365 mm for males (Rodriguez-Roda, 

 1966). 



Subspecies The eastern Pacific population of A. 

 rochei has more scales in the corselet under the sec- 

 ond dorsal fin: therefore we describe it as a separate 

 subspecies. ANCOVAon morphometric characters for 

 populations of A. rochei were not significant, possibly 

 because of the small size range (300-365 mm) for the 

 eastern Pacific sample, but no significant differences 



