180 



FISH HATCHERY MANAGEMENT 



HIRD VENTRICLE 

 QPTIC LOBE 

 ENS OF EYE 



DOE OF MANDIBLE 

 IND BRAIN 

 OTIC CAPSULE 

 ,GILL BAR 



FUTURE PECTORAL FIN 



HEAD-VENTRA 



M. SIXTEEN DAYS AFTER 

 FERTILIZATION, 51. 7T 

 AVERAGE TEMPERATURE 

 (315.9 T.U.). 



N. EIGHTEEN DAYS AFTER 

 FERTILIZATION, 51.8°F 

 AVERAGE TEMPERATURE 

 (357.4 T.U.). 



ORSAL FIN 



CEREBRAL HEMISPHERE, 



OPTIC LOBE 



HIND BRAIN 

 FUTURE 

 FOURTH VENTRICLE 



FUTURE CEREBELLUM, 



ORSAL FIN FOLD 



NAL FIN 



NAL FIN FOLD 



VENTRAL FIN 



0. TWENTY-SIX DAYS AFTER 

 FERTILIZATION, 51. 2T 

 AVERAGE TEMPERATURE 

 (500.4 T.U.). 



Figure 61. Continued. 



dipped into the egg mass and eggs fill the holes as the paddle is lifted 

 through them. 



Three commonly used procedures for counting trout and salmon eggs are 

 the Von Bayer, weight, and water-displacement methods. 



The Von Bayer method employs a 12- inch, V-shaped trough (Figure 62). 



