FISHERY BULLETIN: VOL. 73, NO. 3 

 POSTERIOR STYLIFORM PROCESS 



EXTERNAL WING 



ANTERO-DORSAL PLATE 



r ~ I 



INTERNAL WING 



ANTERIOR PROCESS 



VERTICAL WING 



Figure 66.— Lateral view of inner surface of right basipterygium of pelvic girdles of six species of Sardini. a. Cybiosarda ekgans, 

 Western Australia, 442 mm FL. b. Orcynopsis unicolor, Tunisia, 620 mm FL. c. Sarda chiliensis, Callao, Peru, 437 mm FL. d. Sarda 

 sarda, Tunisia, 504 mm FL. e. Gymnosarda unicolor, Truk Islands, 696 mm FL. f. Allothunnusfallai, Tasmania, 778 mm FL. 



(Figure 67). Gymnosarda differs from the other 

 bonitos in having a single interpelvic process. 

 Auxis and Grammatorcynus also have a single 

 interpelvic process, the former very large, the lat- 

 ter small. However, there is a posterior styliform 

 process from each basipterygium regardless of 

 whether the fleshy interpelvic process is single or 

 bifid. 



INTERNAL WING 



Figure 67.— Ventral view of pelvic girdles and fins of two species 

 of Sardini. a. Orcynopsis unicolor, Tunisia, 495 mm FL. b. 

 Gymnosarda unicolor, Truk Islands, 787 mm FL. a drawn twice 

 as large as b. 



PART 2. SYSTEMATICS 



The family Scombridae can be divided into two 

 subfamilies: the Gasterochismatinae, which con- 

 tains only the aberrant Gasterochisma melampus 

 Richardson, and the Scombrinae. The Scombrinae 

 is composed of two groups of tribes (Figure 68). 

 The more primitive mackerels (Scombrini - 

 Scomber and Rastrelliger) and Spanish mackerels 

 {Scomheromorini— Grammatorcynus, Scombero- 

 mxrrus, and Acanthocybium) have a distinct notch 

 in the hypural plate, lack any bony support for the 

 fleshy caudal peduncle keels (Figure 56), and do 

 not have preural centra two and three greatly 

 shortened. The bonitos comprise a tribe (Sardini, 

 Starks 1910) of five genera and eight species. The 

 bonitos differ from the higher tunas (Thun- 

 nini— Auxis, Euthynnus, Katsuwonus, and Thun- 

 nus) in lacking any trace of a specialized subcu- 

 taneous vascular system, in lacking dorsally 

 projecting lateral cartilaginous ridges on the 

 tongue, and in having the bony caudal keel only 

 partially developed instead of complete. The Sar- 

 dini lack the prominent paired frontoparietal 

 foramina characteristic of the Thunnini (except 

 Auxis). Except for Allothunnus, the Sardini also 

 differ from the Thunnini in lacking prominent 

 prootic pits. In this character, and in its tiny 

 conical teeth, Allothunnus is similar to the Thun- 

 nini. The Sardini agree with Thunnus and with 

 the Scombrini and Scomberomorini in lacking the 

 bony shelf that divides the neural canal of the 

 anterior six vertebrae into dorsal and ventral por- 

 tions. This bony division is characteristic of the 



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