POTTHOFF: DEVELOPMENT AND STRUCTURE OF FINS IN CORYPHAENA 



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C. equiselis -^ 

 C. hippurus ^ 



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LENGTH, mm NL or SL 



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Figure 28. — Number of left pectoral fin rays in relation to length in 164 Coryphaena equiselis (6.5-230 mm NL or SL) and 123 



C. hippurus (5-172 mm NL or SL). For explanation of symbols, see Figure 1. 



fying, except the supratemporal-intertemporals) 

 consisted of ossification and growth of the bones, 

 and the formation of bony shelves on the clei- 

 thrum, coracoid, posttemporal, and postcleithrum 

 1 (Figures 29, 30). The supratemporal developed 

 thin membranous bones around the lateral line 

 canal tubes. Development also involved loss of 

 cartilage. The cartilage separating the sc.apula 

 and coracoid became narrower with increasing 

 length (Figures 29, 30). The cartilage from the 

 prominent larval posterior process of the coracoid 

 completely disappeared by 40 mm SL (Figure 30). 



No developmental studies of the pectoral fin and 

 supports have been done for Coryphaena spp. 

 Starks (1930) studied the anatomy of the pectoral 

 girdle in a variety of adult bony fishes including C. 

 hippurus. The development of the coraco-scapular 

 cartilage to a scapula and a coracoid bone and 

 some or total atrophy of the cartilaginous poste- 

 rior process of the coracoid occurs in most fishes 

 (Swinnerton 1905; Starks 1930). More recently 

 Houde and Potthoff (1976) observed the atrophy of 

 the posterior process in A. rhomboidalis and 

 Saksena and Richards ( 1975 ) reported the presence 



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