"oo ♦►' 



Figure 23. — Exploration of the interaction surface formed by the ratio of the standard length to (a) eye diam- 

 eter, (b) second anal spine length, (c) first dorsal ray length, and (d) last dorsal spine length of plnfish ex- 

 posed to three levels of salinity and three levels of radiation for 45 days. 



The interaction of radiation and temperature 

 resulted in longer, heavier, deeper bodiedfish 

 with relatively longer body parts at 15° C. as 

 radiation levels increased (figs. 24 and 25). 

 At 20° C, the fish receiving 0.83 rads/hour 

 were longer, heavier, and deeper bodied than 

 either fish in the control group or the group 

 receiving 1.28 rads/hour (fig. 24). With in- 

 creased radiation levels at 20° C, there was 

 no change in the relative length of the head, 

 last dorsal spine, first dorsal ray, and second 

 anal spine; a general reversal of trend was 

 evident with increasing levels of radiation 

 between 15° and 25° C (fig. 25). 



The- interaction of radiation, salinity, and 

 temperature changed all measured body char- 



acteristics significantly except the last dorsal 

 spine length and fir st dorsal ray length (table 6). 

 On the basis of the significance of the main 

 effects and their interactions, the significance 

 of the three-way interaction is considered real 

 and not an accident of random fluctuation. 



G rowth in Length from to 45 Days 



An analysis of variance was done on the 

 standard length of pinfish at each of the sample 

 days of 15, 30, and 45 days. At 15 days, the 

 major factor, of those tested, controlling the 

 growth of these fish was temperature. By 30 

 days, radiation, temperature, and their inter- 

 action had become significant; and by 45 days. 



44 



