YOUNG JACK CREVALLES 



475 



or distorted; and the first element of the second 

 dorsal fin (normally the ninth dorsal spine), 

 although having the thickened, shortened, and 

 pointed appearance of a spine, has three segment 

 marks. 

 Characters 



Dorsal spines. — VIII and I. All spines are well 

 formed at 6.0 mm. (fig. 48). The fourth spine 

 averages the greatest length to about 33 mm. 

 standard length; above 33 mm., the third spine is 

 longest. An interspinous membrane connects the 

 eighth and ninth spines to about 90 mm. On 

 specimens 176 to 315 mm. the membrane connect- 

 ing the seventh and eighth spines has disappeared. 



The regression of third dorsal-spine length on 

 standard length is shown in figure 55 and table 12. 

 A line fitted to this regression for specimens from 

 10.5 to 79.5 mm. standard length shows a pro- 

 portional rate of increase for the two variates 

 within this size range (0.12-mm. increase in spine 

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

 The coordinates of the seven specimens larger 

 than 79.5 mm. fall below the extension of the 

 calculated regression line, indicating a decrease 

 in spine growth rate above this size. 



Anal spines. — II and I. The spines are well 

 formed at 6.0 mm. (fig. 48). The second spine is 

 longer than the first at all sizes. An interspinous 

 membrane connects the second and third spines 



to about 35 mm. standard length (figs. 48 and 53). 

 The second anal spine length for the two specimens 

 smaller than 10 mm. is illustrated in figure 4. 



Dorsal soft-rays.— 25 to 28 (table 12). The 

 6.0-mm. specimen has 25 soft-rays — one or more 

 are probably unformed (fig. 48). The 25 soft -rays 

 of the 8.1-mm specimen (fig. 49) may represent 

 the full complement of this fish. Segmentation 

 has begun at 6.0 mm. standard length (fig. 48). 

 The terminal raj' is branched to its base by 10.5 

 mm. (fig. 50), and the other rays become branched 

 between about 17 mm. and 20 mm. (fig. 53). The 

 extension of the anterior 5 or 6 rays to produce 

 the lobe begins at about 15 mm. (fig. 52) and is 

 pronounced by 30 mm. (fig. 53). The second ray 

 averages the greatest length to about 23 mm.; 

 above 23 mm., the first ray is longest. The 

 longest soft-ray averages a greater length than 

 the longest dorsal spine (fig. 55). 



The regression of length of the first dorsal soft- 

 ray on standard length is shown in figure 55 and 

 table 11. A line fitted to this regression for speci- 

 mens from 6.0 to 95.0 mm. standard length shows 

 a proportional rate of increase for the two variates 

 within this size range (0.15-mm. increase in soft- 

 ray length per 1.0-mm. increase in standard 

 length). The spread of the coordinates of speci- 

 mens larger than 95.0 mm. on both sides of the 

 extension of the calculated regression line is 



Figure 53. — Cararu; bartholomaei juvenile, 30.7 mm. standard length (Gill 7, Reg. 27) 



