FISHERY BULLETIN: VOL. 82, NO. 4 



a 



FIGURE 42. — Left supratemporals in lateral 

 view. a. Scomberomorus semifasciatus , New 

 Guinea?, 740 mm FL, 1.5 x . b. Scomberomo- 

 rus multiradiatus. New Guinea, 224 mm FL, 

 5x. c. Acanthocybium solandri, Caribbean 

 Sea, 1,240 mm FL, lx. d. Grammatorcynus 

 bilineatus. New Guinea, 382 mm FL, 3 x . 



branches, but it did have four pores along the 

 main part of the canal. Acanthocybium has a 

 single short posterior branch that opens into a 

 very large pore (Fig. 42c). Grammatorcynus (Fig. 

 42d) lacks a distinct posterior branch but has a 

 relatively longer canal on the lateral side of the 

 bone. 



Cleithrum 



The main body of the cleithrum is crescent- 

 shaped with an anterodorsal spine and a poste- 

 riorly projecting plate at the upper end, as in 

 other scombrids (Fig. 43). The angle between the 

 spine and the plate is wider in Acanthocybium 

 (Fig. 43c) than in Grammatorcynus (Fig. 43d) 

 and the species of Scomberomorus. The bonitos 

 have wider angles (Collette and Chao 1975:fig. 

 61), except for Gymnosarda. The spine extends 

 about as far dorsally as the plate does in Acan- 

 thocybium and all the species of Scomberomorus, 

 except S. sinensis in which the spine extends well 

 past the dorsal margin of the plate. In Gramma- 

 torcynus, the spine does not extend all the way to 

 the margin of the plate (Fig. 43d). The plate 



becomes narrower posteriorly in most species of 

 Scomberomorus and in Grammatorcynus. The 

 posterior plate is longer and of uniform width in 

 Acanthocybium (Fig. 43c). 



The lower part of the cleithrum is large and 

 folded back upon itself as two walls: one lateral 

 and the other mesial, which meet at their ante- 

 rior margins and run parallel to each other. The 

 mesial wall of the cleithrum forms a large tri- 

 angular slit with the coracoid. As Devaraj (1977: 

 46) pointed out, this slit is hidden in lateral view 

 in the species of Scomberomorus by the great 

 width of the lateral wall of the cleithrum. This 

 portion of the cleithrum is narrower in Acantho- 

 cybium and Grammatorcynus, and consequently 

 the upper part of the slit is visible in lateral view. 



Coracoid 



The coracoid is elongate and more or less tri- 

 angular in shape (Fig. 43). It connects with the 

 scapula along its dorsal edge and with the mesial 

 shelf of the cleithrum anterodorsally and antero- 

 ventrally. There is a prominent elongate slit 

 between the cleithrum and the coracoid that is 



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