494 



FISHERY BULLETIN OF THE FISH AND WILDLIFE SERVICE 



Table 16. — Caranx latus: Statistics describing regressions of body parts on standard length 



f=mean of independent variable x 



y = mean of dependent variable y 



N"=number of specimens 



6 = rate of increase of y 



a = y-intercept of regression line 



Sy-z=standard deviation from regression (standard error of estimate) 



longer than the first at all sizes. An interspinous 

 membrane connects the second and third spines to 

 about 35 mm. 



Dorsal soft-rays.— 19 to 22 (table 17). At 16.1 

 mm. the posterior rays are beginning to branch 

 (fig. 69). Extension of the anterior 5 or 6 soft- 

 rays to produce the lobe has occurred by 31.9 mm. 

 (fig. 71). The second ray averages the greatest 

 length to about 34 mm. standard length; above 

 34 mm., the first ray is longest. The third dorsal 

 spine averages longer than the first soft-ray to 

 about 50 mm.; above 50 mm., the soft-ray is 

 longer (fig. 73). 



The regression of length of the first dorsal soft- 

 ray on standard length is shown in figure 73 and 

 table 16. A line fitted to this regression for spec- 

 imens from 31.9 to 119 mm. standard length il- 

 lustrates appreciable variation of coordinate 

 values around the line, but indicates a propor- 

 tional rate of increase for the two variates within 

 this size range (0.21-mm. increase in soft-ray 

 length per 1.0-mm. increase in standard length). 

 Alinement of the coordinates of the three smallest 

 specimens of latus and of the "latus and/or hippos" 

 specimens suggests that a slower soft-ray growth 

 rate prevails below approximately 30 mm. The 



Table 17. — Caranx latus: Correlation of the numbers of 

 dorsal and anal soft-rays of 88 specimens 



[The upper number in each block is the count obtained for that combination, 

 and the number in parentheses below is the approximate percentage 

 of that count in the total sample] 



DORSAL SOFT-RAYS 



as 



h 



o 



< 



coordinates of the specimens larger than 119 mm. 

 fall above the extension of the calculated regres- 

 sion line, indicating an increase in soft-ray growth 

 rate above that size. 



Anal soft-rays.— \6 to 18 (table 17). Only the 

 terminal ray is branched at 16.1 mm. standard 

 length (fig. 69). Lobation occurs as with the 

 dorsal fin. The second soft-ray is longest to 21.8 

 mm. standard length; the first and second rays 

 are equal and the longest at 34.4 mm.; and the 

 first ray is longest at 36.5 mm. and above. The 

 longest anal ray is shorter than the longest dorsal 

 ray at 16.1 mm. and above 34 mm.; and they are 

 nearly equal in length from 21.8 to 34.1 mm. 

 The second anal spine is about two-thirds as long 

 as the longest anal soft-ray at 16.1 mm., only 

 about one-half as long at 40 mm., and about one- 

 fourth as long at 141 mm. 



Interneural and interhemal spines. — The poste- 

 rior lateral projections of these spines are well 

 developed and extend above the body surface 

 along the bases of the second dorsal and the anal 

 fins at 16.1 mm. standard length (fig. 69). They 

 remain externally discernible to 156 mm., but are 

 much less prominent than at smaller sizes. At 

 172 mm., these projections along the dorsal fin 

 base are covered by the fleshy sheath that covers 

 the bases of the soft-rays, but approximately 6 of 

 the projections of the interhemal spines along the 

 anal fin base remain externally exposed. 



Caudal. — 9 + 8 principal rays; about 8 or 9 + 

 8 secondary rays. Branching has occurred at 

 16.1 mm. (fig. 69). 



Pectoral. — 1-18 to 20. The full complement of 

 rays is formed by 16.1 mm. standard length (fig. 

 69). The distal end of the fin is rounded to about 

 32 mm. standard length, after which it becomes 

 pointed and falcation begins (figs. 69 to 71). Fal- 



