514 



FISHERY BULLETIN OF THE FISH AND WILDLIFE SERVICE 



for specimens of about 57 to 600 mm. (converted) 

 from the Atlantic, Gulf, and Caribbean. Schultz 

 (1949: 124), listing hippos from Venezuela, gave 

 an upper limit of 40 scutes. These values obviate 

 the character used to separate proposed Atlantic 

 and Pacific subspecies given by Nichols (1937a: 

 59), who gave a range for specimens over 100 mm. 

 standard length of 27 to 33 scutes for C. h. hippos 

 and 33 to 40 for C. h. caninus. Some of the scutes 

 have completed their individual development at 

 16.1 mm. and nearly all by 100 mm. The mean 

 numbers of scutes of the three largest specimens 

 examined, 770 mm., 795 mm., and 830 mm., were 

 30, 23.5, and 24.5, respectively. The two lowest 

 scute counts were obtained on the two largest 

 specimens — this is probably caused by the terminal 

 scutes losing their posterior spines with growth 

 and consequently being omitted from the count. 

 Lateral line. — Range of mean lateral-line ratio 



from approximately 55 to 430 mm. standard 

 length: about 1.15 to 1.55 (fig. 93). The mean 

 lateral-line ratio-standard length relation has 

 appreciable variation, but the ratio tends to 

 increase up to about 60 mm. and to become con- 

 stant or to decrease slightly above this size. 

 Nichols (1937a: 58) gave ratios of 1.1 to 1.2 for 

 specimens 109 to 145 mm., and he (1937c: 1) gave 

 ratios of 1.1 to 1.3 for specimens 23 to 65 mm. 

 His values are accommodated by the perimeters of 

 figure 93 but average lower than those I obtained. 

 The mean lateral-line ratios of the three largest 

 specimens examined, 770 mm., 795 mm., and 830 

 mm., were 0.97, 1.47, and 1.15, respectively. The 

 value for the 770-mm. specimen was the lowest 

 that was obtained. 



Preopercular spines. — Preopercular spines were 

 present on specimens from 12.7 to 22.1 mm. 

 standard length, but absent on specimens of 21 



100 



200 



300 400 500 



STANDARD LENGTH IN MM. 



700 



800 



Figure 91. — Caranx hippos: Relation of pectoral length, of head length, and of snout length to standard length, showing 

 calculated regression lines (solid lines) for specimens smaller than 300 mm. standard length and coordinates of 

 and estimated regression lines (dashed lines) fitted to specimens from 377 to 830 mm. standard length. 



