COLLETTE and CHAO: SYSTEMATICS AND MORPHOLOGY OF THE BONITOS (SARDINI) 



Figure l.-Diagramatic lateral views of three species of Sardini 

 to show general pigment pattern, extent of corselet (coarse 

 stippling), and parts of the body covered by smaller scales (fine 

 stippling), a. Cybiosarda elegans, New South Wales, 337 mm FL, 

 USNM 259407-F2. b. Orcynopsis unicolor, Tunisia, 312 mm FL, 

 USNM 206526. c. Sarda sarda, Gulf of Mexico, 287 mm FL, 

 USNM 118646. 



38) includes color photographs of a northeastern 

 Pacific Sarda chiliensis and an eastern Pacific S. 

 orientalis. 



Scales 



In bonitos, the body scales are cycloid and 

 usually small. Those on the corselet, along the fin 

 bases, and along the lateral line are larger and 



more elongate. The predorsal and opercular scales 

 are larger and are embedded under the skin. No 

 scales are present on the snout, the interorbital 

 area, or on the fins. Posterior to the corselet, the 

 distribution of scales differs among the genera of 

 bonitos (Figures 1, 2). Species of Sarda have their 

 body completely covered with small scales except 

 for the distal portion of the caudal keels (Figure 

 Ic). Allothunnus has the dorsal half of the body 

 covered with scales (Figure 2b), but they do not 

 extend onto the caudal keels, although they do 

 cover the base of the caudal fin. Serventy (1948) 

 described the type of Allothunnus fallai as hav- 

 ing its whole body covered with scales. But later 

 authors, Talbot (1960), Olsen (1962), and 

 Nakamura and Mori (1966), all indicated that the 

 minute scales of Allothunnus are present only on 



a 



Figure 2.— Diagrammatic lateral views of two species of Sardini to show extent of corselet (coarse stippling) and parts of body 

 covered by smaller scales (fine stippling), a. Gymnosarda unicolor, Tahiti, 446 mm FL, ANSP 93818. b. Allothunnus fallai, New 

 Zealand, 642 mm FL. 



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