404 



FISHERY BULLETIN OF THE FISH AND WILDLIFE SERVICE 



Ventrah. — The ventral fin buds are first evident 

 at a larval size of about 4.0 mm. total length. 

 Rays are visible by 7.0 mm. standard length, and 

 1 spine and 5 rays are present by a larval size of 

 14.5 mm. (figs. 9 to 13). 



BODY PROPORTIONS 



As occurs in many fish, the greatest changes in 

 body proportions of the silver mullet take place 

 between hatching and a length of 4 to 5 mm. 



The head length, eye diameter, and body depth 

 (at pectoral) all increase at a rapid rate during 

 the initial period; slow down when the larvae are 

 between about 5 and 25 mm. long; and stabilize 

 at a constant rate from 25 mm. to adult size. 

 These relations are demonstrated in figures 17, 18, 

 and 19. The slight upward shifts in the regression 

 lines for head length and body depth (at pectoral), 

 which occur in fish about 25 to 30 mm. long, take 

 place at the time the young mullet leave the open 

 ocean and move to beach and estuarine habitats. 



I believe that a greater abundance of food avail- 

 able on these inshore nursery grounds results in 

 an initial rapid growth reflected in these body 

 parts. Young mullet, between 20 and 25 mm. 

 long, from the open ocean appear thin and never 

 seem to have full bellies, whereas young mullet 

 taken from the estuarine areas usually have 

 stomachs somewhat distended. 



The distances from snout to insertion of first 

 dorsal fin, snout to insertion of second dorsal 

 fin, and snout to insertion of anal fin increase at a 

 remarkably uniform rate from a larval size of 

 3-4 mm. to adults. These relations are given in 

 figures 20 and 21. 



Jacot (1920, p. 223) said that the developmeni, 

 of M. curema was much as in M. cephalus but 

 without a definite silvery stage and with a con- 

 stant rate of development of the various parts 

 and of the individual. However, Jacot's smallest 

 specimens were 20 mm. long, and he gives no 

 other measurements. 





J 



Figure 15. — Juvenile, 50.0 mm. 





Figure 16. — Juvenile, 110.0 mm. 



