THE PROPAGATION OF THE GOLDFISH 



Mating. The mating season of the goldfish is during the warm 

 spring and summer months, when the water is at 60° or over, and spawn- 

 ings occur at frequent intervals, as with this species of Cyprinidae all the 



FIG. 55. Embriology of the Goldfish. 



Newly exuded egg, not fecundated, wrin- 

 kled and unexpanded surface covered 

 with vesicles. Full and lateral views. 



Egg, four and ten hours after fecundation, 

 showing germination and formation of 

 membrane. 



Development of embrio and plasmic pro- 

 cesses at edge of membrane, 24 and 34 

 hours after spawning. 



4. Development of alevin and yolk-sac, 50 

 and 58 hours after spawning. 



5 , Free-swimming alevin attached to the yolk- 

 sac, showing skeleton, partly developed 

 digestive organs and surface colors. 

 Four days old. 



6. Alevin five days old; dorsal and caudal fins 

 partly developed. 



7. Alevin seven days old; pectoral and anal 

 fins developed. 



The fully developed Telescope fry, ten 

 days old. 



Greatly enlarged, i^ctual size, No. 8, |- 



eggs do not mature at the same time. During this period the distinguish- 

 ing characteristics of the male are developed and consist |of wartlike pro- 

 tuberances or papillose tubercles on the operculse and main rays of the pec- 

 toral fins, Fig.. 10 (page 46), which have distinct sexual purpose. Another 



90 



