FISHERY BUIXETIN: VOL. 78, NO. 2 



Table 5. — Sum ladult count) of anal fin pterygiophores in the 

 two anteriormost interhaemal spaces, numbers 14 and 15, in 

 35 Coryphaena hippurus (49.9-176 mm SL) and 32 C. equiselis 

 (74.1-172, 314 mm SLj. For numbering interhaemal spaces, see 

 Figure 3. 



Morphology' and Development 



The pterygiophores in the center area of the 

 dorsal fin developed first in both species. A ptery- 

 giophore (proximal and distal radial) appeared as 

 one elongate piece of cartilage (Figure 6). Ossifica- 

 tion was first observed at the middle part of the 

 pterygiophore cartilage (Figure 6) and proceeded 

 distally and proximally along the cartilage until 

 only cartilage tips were present at the extremities. 

 At this point, the sagittal and lateral keels began 

 to develop (Figure 4). Further development of the 

 pterygiophore consisted of growth of the keels, 

 growth of bone around the locus of secondary fin 



ray association, and segregation and ossification 

 of the distal radial. The distal radial developed 

 from the distal tip of the pterygiophore cartilage 

 late during ontogeny (Figure 6), and ossified into 

 two pieces of bone (Figure 7). 



The pterygiophores in the posteriormost area of 

 the dorsal fin developed similarly to those of the 

 center area. The posteriormost pterygiophore sup- 

 ported one ray in series. This ray developed from 

 two rays but was counted as one according to 

 Hubbs and Lagler (1958). In adults, the base of the 

 anterior ray fitted closely over the base of the 

 posterior ray and the base of the posterior ray 

 articulated with the distal radial of the posterior- 

 most pterygiophore (Figures 8, 9). 



The supports of the anterior portion of the 

 dorsal fin developed last. In C. equiselis the first 

 interneural space was almost filled with cartilag- 

 inous pterygiophores, but in equal-sized C hip- 

 purus the first interneural space was empty and 

 the second interneural space had only one carti- 

 laginous pterygiophore (Figures 10, 11). The ante- 

 riormost cartilaginous pterygiophores always had 



(/) 



14[ 



13 



12f 



n 



10 

 9 

 8 

 7 

 6 

 5 

 4 

 3 

 2 



C. equiselis^ 

 C. hippurus ^ 



^ 10 11 12 ]3 14 15 16 17 18 19 20 21 22 23 24 25^8 33 38 43 



LENGTH, mm NL or SL 



Figure 5.— Number of ossifying pterygiophores in the first interneural space in relation to length in 126 Coryphaena equiselis and 



88 C. hippurus. For explanation of symbols see Figure 1. 



284 



