164 FISH HATCHERY MANAGEMENT 



Overripe Eggs 1 hr. (50X) 



Note Breakdown at Inner 



Surface of Chorion 



/ 



V 



Overripe Eggs 2 hrs. (50X) 



Note Deterioration Confined 



to One-Half of Egg 



Overripe Eggs 1^2 hrs. (50X) 



Breakdown at Inner 



Surface of Chorion Persists 



Overripe Egg 16 hrs. (20X) 



(Dark Areas Appear White 



Under Microscope) 



Figure 55. Development of striped bass eggs that become overripe before ovula- 

 tion. (Courtesy Jack D. Bayless, South Carolina Wildlife and Marine Resources 

 Department.) 



As ovulation occurs, eggs of striped bass become detached from the 

 ovarian tissue. They are deprived of parental oxygen supply, and anoxia 

 can result in a short period of time if the eggs remain in the body. (This 

 also is true for grass carp.) If eggs flov^ from the vent when pressure is ap- 

 plied to the abdomen, at least partial ovulation has occurred. The max- 

 imum period between ovulation and overripeness is approximately 60 

 minutes. The optimum period for egg removal is between 15 and 30 

 minutes following the first indication of ovulation. Eggs obtained 30 

 minutes after initial ovulation are less likely to hatch. 



Prior to manual stripping, female striped bass should be anesthetized 

 with quinaldine sprayed onto the gills at a concentration of 1.0 part per 



