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



other three genera of Thunnini- Katsuwonus, 

 Euthynnus, and Auxis. 



Five genera, four of them monotypic, are 

 recognized as a result of analyzing the morphology 

 described in the first part of this paper. A sample 



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8 S 



in ec 



° SARDINI 



THUNNINI 



O >n < 



T n 



SCOMBRINI SCOMBEROMORINI 



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M 

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GASTEROCHISMATINAE 



SCOM RINAE 



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Figure 68.— The subfamilies, tribes, and genera of the Scom- 



bridae. 



of some of the more important characters is sum- 

 marized in Table 14. Orcynopsis and Cybiosarda 

 form a pair of related genera in characters such as 

 the poor development of the bony caudal keels, 

 location of the spleen, presence of a pair of tooth 

 patches fused to the glossohyal bone, and length of 

 the liver lobes. They differ sharply in vertebral 

 number; Orcynopsis usually has 18 precaudal plus 

 20 caudal vertebrae compared to (22-23) + (24- 

 25) = 47 in Cybiosarda. In some respects, Sarda 

 and Gymnosarda also form a pair of related 

 genera. However, characters of Gymnosarda such 

 as the well-developed swim bladder, curved sagit- 

 ta, large number of olfactory laminae, paired 

 glossohyal tooth plates, location of the spleen, lack 

 of cephalic intermuscular bones, and parhypural 

 fused to the hypural plate demonstrate that Gym- 

 nosarda is very different from the other genera of 

 Sardini. Allothunnus differs strongly from the 

 other bonitos in liver shape, presence of prootic 

 wings, and shape of pineal foramen, but shares 

 more characters in common with the Sardini than 

 with the Thunnini as previously noted. 



Orcynopsis Gill 



Orcynopsis Gill 1862:125 (type-species Scomber 

 unicolor Geoffroy St. Hilaire; misspelled Or- 

 ycnopsis). 



Table 14.— Summary of characters distinguishing the five genera of Sardini. 



591 



