FISHERY BULLETIN: VOL. 82, NO. 4 



ly. The posterodorsal margin of the scapula is 

 drawn out into a facet which accepts the most 

 anterior ray of the pectoral fin. The scapula is 

 pierced by a large, usually round foramen near 

 the lateral margin with the inner shelf of the 

 cleithrum. A prominent suture leads from the 

 scapular foramen to the ventral margin of the 

 scapula. The foramen is largest in Acanthocyb- 

 ium (Fig. 43c), Scomberomorus brasiliensis , and 

 S. regalis. It is smallest in S. guttatus and S. 

 niphonius. We did not find it very large in S. 

 koreanus (Fig. 43e), as stated by Devaraj (1977: 

 47). It is intermediate in size in Grammatorcynus 

 (Fig. 43d) and the other species of Scomberomo- 

 rus (e.g., S. semifasciatus and S. sinensis, Fig. 

 43a, b). 



Pectoral Fin Rays 



The first (uppermost and largest) pectoral fin 

 ray articulates directly with a posterior process of 

 the scapula. The other rays attach to the radials. 

 The number of pectoral rays ranges from 19 to 26 

 in the three genera (Table 12). Most species of 

 Scomberomorus usually have 22 or 23 rays. Five 

 species average fewer, with a mode of 21 rays: 

 concolor, guttatus, maculatus, sierra, and tritor. 

 The two species in the genus with the most 

 pectoral rays are S. plurilineatus (21-26, x 23.1) 

 and S. semifasciatus (22-25, x 23.3). Acanthocyb- 

 ium and Grammatorcynus have slightly higher 

 counts than do the species of Scomberomorus, 22- 

 26, mostly 24 or 25. 



Within the Scombridae, the number of pectoral 

 fin rays increases from the more primitive mem- 



TABLE 12. — Number of pectoral fin rays in Acanthocybium , 

 Grammatorcynus , and the species of Scomberomorus. 



Species 



19 20 21 22 23 24 25 26 



N 



S. brasiliensis 



S. cavalla 



S commerson 



S concolor 



S guttatus 



S koreanus 



S lineolatus 



S. maculatus 



S. multiradiatus 



S. munroi 



S niphonius 



S. plurilineatus 



S queenslandicus 



S regalis 



S semifasciatus 



S. sierra 



S. sinensis 



S. tritor 



Acanthocybium 



Grammatorcynus 



38 

 27 



8 

 20 



1 

 4 

 8 



1 



18 52 

 21 4 



57 

 4 

 2 

 33 

 10 

 4 

 9 

 1 

 5 



11 

 13 



6 

 14 

 10 



4 

 22 



9 

 19 



17 21 

 4 



16 38 



2 



3 22 



17 

 8 



13 

 3 

 1 



21 

 18 



32 



1 



7 



10 



1 



6 



1 



5 



14 



5 



4 



15 



1 



3 



1 



5 







1 



13 



1 



17 

 13 



12 



17 



69 

 51 

 110 

 34 

 89 

 28 

 25 

 56 

 27 

 9 

 36 

 33 

 30 

 44 

 33 

 73 

 13 

 38 

 37 

 42 



22.2 

 22.2 

 22.3 

 20.8 

 20.9 

 223 

 22.2 

 21.1 

 21.8 

 21.7 

 21.9 

 23.1 

 22.1 

 21.7 

 23.3 

 21.1 

 22.1 

 21.3 

 24.1 

 24.3 



bers of the family to the more advanced: Scom- 

 brini 18-21, Scomberomorini 19-26, Sardini 21-28, 

 Thunnini (except for Thunnus) 22-29, Thunnus 

 30-36. 



Radials 



The four radials differ in size and shape and are 

 attached directly to the thickened posterior edges 

 of the scapula and coracoid (Fig. 43). The size of 

 the radials increases posteroventrally. Small for- 

 amina are located between the second and third, 

 and the third and fourth radials counting poste- 

 riorly. In Scomberomorus and Acanthocybium 

 (Fig. 43a-c), the first two radials and the upper 

 third of the third radial attach to the scapula; the 

 ventral third of the third plus the fourth radial 

 attach to the coracoid. In Grammatorcynus the 

 first two radials attach to the scapula, the second 

 two to the coracoid (Fig. 43d). A much larger 

 foramen is present between the largest (fourth) 

 radial and the coracoid. Posteriorly, this foramen 

 is framed by a posterior process of the upper part 

 of the fourth radial meeting an anterior process 

 from the posterior margin of the coracoid. The 

 process on the fourth radial is only slightly devel- 

 oped in Grammatorcynus (Fig. 43d). The foramen 

 is considerably larger than the scapular foramen 

 in five species of Scomberomorus: guttatus, ko- 

 reanus (Fig. 43e), lineolatus , niphonius, and plu- 

 rilineatus. It is slightly larger than the scapular 

 foramen in seven species: commerson, concolor, 

 maculatus, multiradiatus , munroi, queenslandi- 

 cus, and tritor. The two foramina are about equal 

 in size in six species of Scomberomorus (brasil- 

 iensis, cavalla, regalis, semifasciatus (Fig. 43a), 

 sierra, and sinensis (Fig. 43b)) and Grammator- 

 cynus (Fig. 43d). The scapular foramen is much 

 larger than the foramen following the fourth 

 radial in Acanthocybium (Fig. 43c). 



Postcleithra 



The posterior projecting plate of the cleithrum 

 has its posterior end attached to the first post- 

 cleithrum which connects ventrally to the second 

 postcleithrum. The lamellar first postcleithrum 

 (Fig. 44) is kidney-shaped with a narrow upper 

 end, rounded lower margin, concave anterior bor- 

 der and convex posterior margin. In Grammator- 

 cynus (Fig. 44d), the first postcleithrum is very 

 wide and short with a notch in the dorsal margin 

 instead of a pointed end, width /maximum length 

 = 55-62%. It is wider (47-48%) in Acanthocybium 



608 



