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Fishery Bulletin 105(2) 



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Figure 2 



Distribution of members of the crevalle jack iCaranx hippos) complex: (Mediterranean locality records 

 for longfin crevalle jack (C. fischeri) are based solely on literature reports; discussion of geographic 

 distribution appears in individual species accounts). 



Mishra and Krishnan, 2003) reported C. hippos as 

 C. carangus (Bloch) from the Indian Ocean based on 

 misidentifications of Caranx heberi (Bennett). What 

 was once considered to be a single widespread species 

 is herein recognized as consisting of three species (Fig. 

 2). For almost a century, most ichthyologists and fishery 

 biologists who have worked on West African crevalle 

 jacks have failed to distinguish the new species Cai-anx 

 fischeri described herein from C. hippos, although both 

 species are commonly taken together. 



Adults of Caranx hippos from opposite sides of the 

 Atlantic Ocean are indistinguishable externally but ex- 

 hibit consistent differences in the degree of development 

 of the hyperostosis in the first dorsal-fin pterygiophore 

 and neural spines of some of the anterior vertebrae (see 

 "Geographic variation" in C. hippos species account). 

 Although we consider these predictable ontogenetic and 

 consistent site-specific patterns obvious evidence of 

 genetic divergence associated with bone metabolism, 

 an important consideration is the unknown functional 

 significance of hyperostosis. In light of this, we believe 

 it would be premature to recognize the eastern Atlantic 

 population of C. hippos as taxonomically distinct. No 

 formal change in classification should be made in the 

 absence of collaborative molecular data. 



The Caranx hippos complex 



The C. hippos species complex can be diagnosed by the 

 following combination of characters: a pair of strong 

 symphyseal dentary canines (Fig. 3); breast naked ven- 

 trally except for a small oblong patch of prepelvic scales 

 (Fig. 4) which forms at about 30 mm FL; rounded black 

 blotch on the lower rays of the pectoral fin in adults; 

 large black opercular spot; and vertebrae 10 precaudal 

 -I- 14 caudal. Only the black blotch on the pectoral fin 

 is unique to these species. Adults of the horse-eye jack, 

 Caranx latus Agassiz, occasionally have a somewhat sim- 

 ilarly placed dusky blotch on the pectoral fin (although 

 the dark area is different in character and never as well 

 defined as in C. hippos), and this similarity in appear- 

 ance has occasionally resulted in field misidentifications, 

 especially by scuba divers unfamiliar with both species. 

 The typical breast squamation pattern of the C. hippos 

 species complex is not duplicated in any other Atlantic or 

 eastern Pacific species of Caranx, although it occurs in 

 three Indo-west Pacific species: commonly in C. ignobilis 

 (Forsskal) and C. papuensis Alleyne and Macleay, and 

 less frequently in C heberi. Dentition has been used as 

 an important diagnostic character of carangid genera, 

 but comparison of the dentition of a large number of 



