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



patches of teeth are present on the vomer and 

 tongue in some genera. Allothunnus has many 

 very small teeth (40-55) on each of the upper and 

 lower jaws, compared to a range of 12-31 on the 

 upper jaw and 10-25 on the lower jaw in other 

 bonitos (Tables 5, 6). Orcynopsis averages more 

 teeth in both upper and lower jaws than does 

 Cybiosarda. Both Gymnosarda and Sarda aus- 

 tralis have a very wide range in the number of jaw 

 teeth. In the eastern Pacific, the tropical Sarda 

 orientalis differs from the south and north 

 temperate S. chiliensis in having fewer upper 

 (13-20, X 16.2 vs. 18-30, x 23.5) and lower (10-17, x 

 13.2 vs. 14-25, X 19.2) jaw teeth. Numbers of jaw 

 teeth and gill rakers are correlated: note especially 

 Allothunnus with 70-80 gill rakers and Orcyriopsis 

 with more gill rakers than Cybiosarda (Table 7). 



Premaxilla.— The premaxilla (Figure 30) is a 

 long curved bone with a stout arrowhead-shaped 

 anterior end and teeth on the ventral margin. The 

 angle between the oblique anterior and the ventral 

 margin of the premaxilla is most acute in Gym- 

 nosarda and Orcynopsis, similar to Scom- 



beromorus. It is almost perpendicular with a small 

 anterior projection in Allothunnus (Figure 30f ), as 

 in Thunnus. The sharp anterior dorsal process of 

 the premaxilla in the species of Sarda separates 

 them from the other bonitos (Figure 30c, d). The 

 posterior end of the premaxilla in Allothunnus is 

 also similar to Thunnus, sharper and thinner than 

 in the other bonitos. The main axis of the 

 premaxilla is curved more in Gymnosarda, 

 Cybiosarda, and Orcynopsis than in Sarda and 

 Allothunnus. 



Maxilla. -The maxilla (Figure 31) is a long 

 curved bone with two irregularly shaped condyles 

 which join the premaxilla anterodorsally. The 

 main axis of the maxilla is most curved in Or- 

 cynxypsis and most flattened in Gymnosarda and 

 Allothunnus (as in Thunnus). A process from the 

 lower condyle of the anterior portion of the max- 

 illa protrudes ventrally in Cybiosarda and the 

 species of Sarda. This projection is not present in 

 Scomberomorus or Thunnus. The posterior ends of 

 the maxillae of Gymnosarda and Allothunnus are 

 broader than in other bonitos. The anterior ends of 



Table 6.-Number of teeth in the lower jaw of species of Sardini. (Mean of left and right sides rounded off upwards to nearest whole 



number.) 



Species 



10 11 12 13 14 15 16 17 18 19 20 21 22 



23 



24 25 



Cybiosarda elegans 



Orcynopsis unicolor: 

 E Mediterranean 

 Cent. Mediterranean 

 Atlantic 



Total 



Sarda australis 



Sarda chiliensis: 

 NE Pacific 

 SE Pacific 



Total 



Sarda orientalis: 

 Indian Ocean 

 NW Pacific 

 Cent. Pacific 

 E Pacific 



Total 



Sarda sarda: 

 Nortfi America 

 South America 

 NE Atlantic 



Mediterranean-Black Sea 

 (Demir 1964, Turkey) 

 Gulf of Guinea-S. Africa 

 Total 



Gymnosarda unicolor: 

 Indian Ocean 

 W Pacific 



Total 



Allothunnus lallai 



5 12 

 1 — 



18 

 8 



16 



7 



10 

 2 



12 



26 23 13 12 13 



4 3 



3 5 



3 



3 6 



10 17 



(1 

 3~ 



2 



4 



12 

 2 



2 

 9 

 5 



18 

 2 

 1 

 4 



21 

 3 



15 

 4 



6 

 18 



7 



3 

 3 

 4 

 3 



22 

 6 



2 



3 



10 



18 



2 



1 



4 



16 



2 



2 



1 

 3 



1) 



21 28 32 19 17 



3 — 



4 — 

 3 4 



— 1 



1 



— 1 



1 



11—1 

 (41-42-49-53) 



23 13.0 



138 



9 

 24 



33 

 4 



16.0 



13.5 

 13.9 



13.8 

 46.3 



555 



