in dilution and concentration experiments varied 

 between 5.91 and 12.58 mg/liter depending 

 largely upon the ambient range of temperature 

 and salinity conditions encountered (Table 1). It is 

 evident in Table 1 that no significant differences 

 exist between flow rates at the beginning and end 

 of a given group of experiments. 



The results of one typical set of dilution and 

 concentration experiments are presented in Fig- 

 ure 1. A comparison of this set of experiments 

 reveals that Mya acclimates faster to high salinity 

 from 17%o than to 17%o from high salinity. 

 Similar observations were noted for all ambient 

 temperature ranges used. The approximate 

 number of hours required to acclimate to each 

 dilution from the control was recorded for each 



TABLE 1. — Parameters recorded during dilution (D) and concen- 

 tration (C) experiments with Mya arenaria at ambient tempera- 

 ture ranges. 



Experiment 



2.9°-3.2 c C: 

 D 



6.4°-6.9 c C: 

 D 



10.0°-10.7°C: 

 D 



15.4°-16.3°C: 

 D 



Tank 

 salinity 



(°/oo) 



Water 

 temp 



Row rate (ml/min) 

 eginning End 



'31.36 + 

 27.371 

 22.48 ± 

 16.88i 

 11.49i 



31.16± 

 27.41 1 

 22.071 

 1 16.58i 

 11.58! 



'31.80! 

 27.16! 

 22.35! 

 16.93! 

 11.91 ! 



31.43! 

 28.04! 

 22.65! 

 '17.14! 

 11.89! 



'30.54! 

 27.15! 

 21.66! 

 16.82 = 

 11.71 d 

 31.18! 

 28.09: 

 21.82: 



'16.26: 

 12.04: 



'31.01: 

 27.55: 

 22.53: 



16 95: 

 12.05: 



30.89: 

 27 57: 

 22 95: 



'17.11: 

 11.78: 



0.04 

 008 

 0.04 

 0.05 

 0.06 



0.06 

 0.10 

 0.04 

 0.03 



:0.12 



:0.15 

 :0.17 

 0.07 



:0.08 

 :0.13 



:0.05 

 :0.06 

 :0.12 

 :0.07 

 :0.03 



:0.06 

 :0.11 

 :0.08 

 :0.06 

 :0.03 

 :0.07 

 :0.03 

 :0.07 

 :0.11 

 :0.32 



:0.07 

 t0.15 

 t0.11 

 t0.06 

 £0.04 



t0.09 

 t0.07 

 !0.14 

 !0.09 

 !0.03 



2.910.2 1,1321 94 1,184±104 



3.2i0.2 1,170i106 1.1561115 



6.910.3 1.152i 71 1,1561 45 



6.410.2 1,100i 66 1,064i 70 



10.0±0.2 1, 1091122 1,111 ±112 



10.7±0.1 1,068i123 1,084i123 



16.310.1 938± 75 980i 62 



15.410.1 1,028i 79 957 1 78 



>■ 26 



X 24 



-I 



1 22 

 CO 



o: 20 

 o 



=> 18 

 o 



^ 16 



_l 

 -> 14 



£" 



10 



r 



A. -A- 





■-M-; 



31.80 -~ 27.16 



31.80 -*■ 2235 



31.80 — »• 16,93 



V v V 



■«•«, 31.80 — «■ 11.84 



132 



30 



28 



• 26 



24 



 22 



20 

 18 

 16 



14 

 12 



10 20 30 40 50 60 70 80 90 100 110 120 130 140 

 TIME IN HOURS 



CONCENTRATION 



— '10 

 150 



? 2S 



_ 26 



i 24 



_i 



< 22 

 CO 



ol 20 



14 



12 



i L 



17.14 ». 3142 



r 



I! 



f* 



I 



L 



3? 

 30 

 28 

 26 

 24 

 22 

 20 



- ie 



£rr 



"■^-v-. 



1714 



■* 



16 



• 14 



q,  12 



1 ' ' 



'Control. 



5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 



TIME IN HOURS 



FIGURE 1. — Shell liquor salinity acclimation rates for Mya 

 arenaria in dilutions and concentrations at 6.4°-6.9°C (lines 

 fitted by eye). 



ambient tempreature range used, plotted for each 

 dilution in Figure 2, and the appropriate curve 

 was fit. Hence at 8°C in Figure 2, 95 h are required 

 for Mya to acclimate to 1 1.49-12. 05°/oo salinity 

 from the control, 45 h to 16.82-16.95%o from the 

 control, 15 h to 21.66-22.53°/oo from the control, 

 and 10 h to 27.15-27.55°/oo from the control. In 

 Figure 2, a geometric relationship exists between 

 temperature and acclimation time after immer- 

 sion into various dilutions. The approximate time 

 required to acclimate to each concentration from 

 the control, at each ambient temperature range, 

 was recorded in Table 2. Tested at 95% confidence 

 intervals (±2 SE), Table 2 reveals that no sig- 

 nificant differences exist between the mean 

 numbers of hours required to acclimate to each 

 concentration experiment at all temperature 

 ranges combined. Table 2 also reveals that no 

 significant differences exist between the mean 



227 



