FISHERY BULLETIN: VOL. 73, NO. 1 



-30C- 



-27C 



24C ir 



-2IC- 



1 ju^ 11 I r- 



I I I II I I I „ | I I I , I I , I I I , I , I , I , 1 I I I I I . I I I I I , 1 I — I I I 



I I I 



'III 



I I I I I 



I I I I I I I I I I I l_l l_L 



14 16 18 20 



16 18 20 22 24 26 28 30 32 34 36 38 40 42 

 TIME (hours after fertilization) 



Figure 6. — Cumulative percentage of larvae hatching, as a function of time after fertiliza- 

 tion, for the Series B experiments. Percentage hatching is plotted on a probabihty scale; lines 

 were fitted by eye. 



Table 6. — Percentage of postmature unhatched eggs at various 

 combinations of temperature and salinity in Series B. There are 

 two replicates at each treatment combination. Series A showed 

 similar trends. 



Salinity 



(°/oo) 



Temperature 



21 



24 



27 



30 



15 

 20 

 25 

 30 



35 

 40 

 45 

 50 

 55 



17.9 

 23.5 



2.1 

 2.0 



4.0 

 7.5 







40 



19.2 

 13.9 



7.8 

 4.4 





 0.9 



16.4 

 11.1 



4.0 

 3.2 



7.2 

 5.2 



5.5 

 9.9 



43.4 

 31.8 



6.7 

 23.0 



3.1 

 2.1 



At 30°C, all eggs died at or before gastrulation 

 at 50%o; at 40°/oo, a small proportion of the eggs 

 survived the high early mortality but most of 

 these failed to hatch, only 4-6% hatching success- 

 fully in Series B (Table 7). At 20 and 30%o at 30°C, 

 most embryonic mortality occurred after the em- 



Table 7.— Percentage total and viable hatch of fertiHzed eggs in 

 various combinations of temperature and salinity in Series A 

 and B. In each series there were two repUcate groups of eggs (a 

 and b) at each treatment combination. 



Temper- 

 ature 

 (°C) 



18 



21 



24 



27 



30 



Salin- 

 ity 

 (O/oo) 



10 

 20 

 30 

 40 

 50 



15 

 25 

 35 

 45 

 55 



10 

 20 

 30 

 40 

 50 



15 

 25 

 35 

 45 

 55 



10 

 20 

 30 

 40 

 50 



Percentage 

 total hatch 



Percentage 

 viable hatch 



Series A 

 a b 



Series B 

 a b 



Series A 

 a b 



Series B 

 a b 





 

 

 

 



66.7 

 25.0 

 27.6 



1.9 









 62.6 

 34.3 

 24.2 



8.0 



67.7 

 22.6 

 40.9 

 11.9 

 







12.0 

 1.0 

 

 





 

 

 

 



82.5 

 40.4 

 37.0 



7.1 









 39.8 

 53.5 

 51.4 



9.9 



66.0 

 34.1 

 41.5 



4.5 









 14.4 

 1.0 

 0.9 

 





 

 

 

 



88.4 

 94.7 

 72.7 

 72.8 

 





 96.0 

 75.6 

 66.3 

 66.3 



76.2 

 79.8 

 784 

 42.9 

 1.0 





 85.9 

 62.2 



4.1 









 

 

 

 



76.5 

 92.9 

 68.8 



47.5 

 





 96.0 

 89.0 

 80.0 

 41.2 



89.9 

 88.4 

 79.2 

 31.9 

 2.0 





 73.8 

 60.0 



6.2 









 

 

 

 



2.0 

 20.0 

 16.3 













 33.3 

 28.3 

 10.1 



1.3 



7.1 

 22.6 

 30.7 















7.0 





















 

 

 



7.5 

 29.3 

 35.0 



2.0 









 23.5 

 44.6 

 38.3 



2.8 



4.1 

 30.6 

 29.8 



1.5 











3.1 

















 

 

 

 



77.9 

 77.9 

 50.6 

 18.1 

 





 70.0 

 63.0 

 34.6 







68.2 

 70.8 

 57.5 













 38.2 

 15.2 













 

 

 

 



68.4 

 59.7 

 38.8 

 11.9 

 





 80.2 

 70.2 

 53.8 







81.1 

 81.0 

 54.7 













 28.6 

 14.6 











bryos had developed pigmentation, although at 

 30%o abnormal development was apparent in 

 many eggs during cleavage and gastrulation 



10 



