POTTHOFF: DEVELOPMENT AND STRUCTURE OF FINS IN CORYPHAENA 



5- 



= 3 



6 10 



II 



6 



\ \ 



2 3 



I 



C.equiselis -^ 

 C.hippurus -3- 



11 



12 



LENCTH.mmNLorSL 



Figure 35. — Number of pelvic fin rays in relation to length in 15 Coryphaena equiselis 

 (7.0-12.4 mm SL) and 52 C. hippurus (6.0-12.5 mm NL or SL). For explanation of 

 symbols, see Figure 1. 



Table 13. — Development of pelvic fin and supports in 52 Coryphaena hippurus (6.0 mm NL-12.5 mm SL) (C h.) and 15 C. equiselis 

 (7.0-12.4 mm SL) (C . e.). Numbers denote number of specimens, dashes denote specimens not available. 



5.6- 6.5 

 6.6- 7.5 

 7.6- 8 5 

 8.6- 9.5 

 96-105 

 10,6-11.5 

 11.6-12.5 





 11 



4 

 10 

 8 

 6 

 3 



4 

 12 

 

 

 

 

 





 5 

 4 

 10 

 8 

 6 

 3 



4 

 10 

 

 

 

 

 



to ossify shortly after the appearance of the 

 anterior xiphoid process (Figure 34). 



A comparison of pelvic bones of Coryphaena spp. 

 with those of more primitive fishes revealed the 

 absence of radials in Coryphaena spp. It is not 

 known if the radials have been lost, or if they have 

 fused to the central part and the articular car- 

 tilage during evolution. In the more primitive 

 stomiatoid fish families (Weitzman 1974) and in 

 Lile piquitinga (Gomez Gaspar 1976), radials are 

 present between the bases of the fin rays. 



DISCUSSION 



In a tentative classification of the Perciformes, 

 Greenwood et al. (1966) placed the Coryphaen- 

 idae to follow the family Carangidae. This place- 

 ment was arbitrary because Coryphaena spp. is 



more advanced than some families that follow in 

 the placement. 



The one continuous dorsal fin of Coryphaena 

 spp. extends to the head, so that the first inter- 

 neural space, bounded by the head bones and the 

 first neural spine, is occupied by pterygiophores 

 which support the fin rays. Smith and Bailey 

 ( 1961) contended that the dorsal fin of Coryphaena 

 spp. represents an evolutionary advance and spe- 

 cialization because of its anterior extension and 

 the loss or reoccupation by fin rays of the predorsal 

 bones. In diverse fishes, such as characins, sparids, 

 carangids, scombrids, and lutjanids, the pterygio- 

 phores in the posterior parts of the dorsal and anal 

 fins have three parts. This triserial pterygiophore 

 structure is considered basic (Eaton 1945; Lindsey 

 1955; Johnson 1978). Most pterygiophores in Cory- 

 phaena spp. are biserial, and one or two anterior- 

 most ones uniserial. Thus, the pterygiophores of 



309 



