vertebrae, any vertebra associated with a pair 

 of pleural ribs was counted as precaudal, any 

 vertebra lacking pleural ribs was counted as 

 caudal. 



In the cleared and stained juveniles, the modal 

 group of dorsal-fin elements was 55 to 57 (Table 

 1), which is more similar to the modal group 

 of 56 to 60 for Atlantic C. hippurus (Gibbs and 

 Collette, 1959) and of Pacific C. hippimis (Roth- 

 schild, 1964) , than to that of C. equiselis (51-55) 

 which these authors reported. The higher mode 

 in these specimens of C. equiselis from the trop- 

 ical mid-Atlantic may be representative of an 

 oceanic population, diff"erent from that sampled 

 by Gibbs and Collette (1959) who may have in- 

 cluded specimens from more than one popula- 

 tion. On the other hand, I may have counted 

 elements in the cleared and stained specimens 

 that were not visible to Gibbs and Collette 

 (1959) in their untreated specimens. 



Counts of the anal-fin elements of the speci- 

 mens from the tropical mid-Atlantic (Table 1) 

 were not appreciably different from those re- 

 ported by Gibbs and Collette ( 1959) . However, 

 the mode was one fin ray higher than those from 

 the Pacific reported by Rothschild (1964) . Total 

 gill raker counts (Table 1) of my specimens 

 were not appreciably different from those re- 



ported by Gibbs and Collette (1959) for young 

 C. equiselis, but differed from Rothschild's 

 (1964) total counts on adult specimens by two 

 or three rakers. My gill raker counts were 

 made on cleared and stained juvenile specimens 

 and did not include tooth patches on the epi- 

 branchial and hypobranchial bones; the gill 

 raker in the epi-ceratobranchial angle was in- 

 cluded in the ceratobranchial count. Total 

 counts tended to decrease as fish size increased, 

 which led me to believe that the rakers over the 

 epibranchial and hypobranchial bones are grad- 

 ually transformed into tooth patches. In spe- 

 cimens below 30 mm SL, the gill rakers over the 

 epibranchial and hypobranchial bones were very 

 small with many minute teeth. In intermediate- 

 sized specimens (40-60 mm SL) some tooth 

 patches could be counted over the two bones 

 along with gill rakers. The epibranchial and 

 hypobranchial bones of juveniles above 80 mm 

 SL were all covered with fine teeth; the hypo- 

 branchial bone had no gill rakers associated with 

 it, whereas the epibranchial usually had one gill 

 raker. 



Size distribution of juvenile C. equiselis caught 

 during the drift period is shown in Figure 3. 

 The mode is from 40 to 44 mm SL. From size 



Table 1. — Frequency distribution of some meristic characters of juvenile Coryphaena equiselis from the tropical 

 mid-Atlantic and data on juvenile and adult C. equiselis from Gibbs and Collette (1959) and Collette et al. (1969). 



878 



