436 



FISHERY BULLETIN OF THE FISH AND WILDLIFE SERVICE 



-| 1 1 r 



100 150 200 



STANDARD LENGTH IN MM 



300 



Figure 1L — Comparison of the variations of the mean lateral-line ratio with respect to standard length for five species 



of Caranx. 



mean number of scutes in dentex overlaps the 

 upper portion of this range in bartholomaei, while 

 the range of the mean lateral-line ratio falls below 

 that in bartholomaei; and the mean number of 

 scutes of the one specimen of lugubris falls within 

 the scute range of hippos; while the lateral-line 

 ratio of lugubris is well above the range of the 

 lateral-line ratio of hippos. However, intraspe- 

 cifically no obvious correlation between the mean 

 number of scutes and the mean lateral-line ratio 

 occurs in specimens larger than about 70 mm. 

 standard length. 



Preopercular spines. — There arc indications that 

 the preopercular-angle spines cease to grow be- 

 tween about 5.4 mm. and 7 mm. standard length 

 in crysos and the "latus and/or hippos" series, and 

 they begin to decrease in length between this size 

 range and 10 mm. (fig. 15). The angle spines of 

 ruber and bartholomaei apparently begin to de- 

 crease in length at sizes smaller than 18 mm. and 12 



mm., respectively. The angle spines, the last re- 

 maining spines, have been absorbed or overgrown 

 by the expanding margin of the preoperculum be- 

 tween 16 to 20 mm. in latus, 21 to 22.5 mm. in 

 hippos, about 38 mm. in bartholomaei, and about 44 

 mm. in crysos and ruber. The number of preoper- 

 cular upper-limb and lower-limb spines varies to 

 such a great degree intraspecificially that only 

 slight interspecific differences can be adjudged 

 (table 1). C. crysos averages a higher number of 

 spines on both limbs than do the other species. 

 The lower limb of all species averages more spines 

 than the upper. The number of spines on both 

 limbs decreases above about 15 mm. — the spines 

 on both limbs nearest the angle spine are the last 

 to disappear. 



Pigmentation. — Comparative reference to the 

 illustrations will point out most of the interspecific 

 differences in pigmentation of larval and juvenile 

 forms. A few distinctions are listed here. 



