Klibansky and Juanes; Effects of preservation on oocytes of tfiree Atlantic fish species 



543 



Table 3 



The effects of experimental treatment (Gilson's, ethanol, freezing, and split-formalin) on oocyte diameter among the species 

 Atlantic cod (Gadus morhua), haddock iMelanogrammus aeglefinus), and American plaice (Hippogtossoides platessoides) within 

 the regions of Georges Bank (GB). the Gulf of Maine (GOM), or within both regions combined (Combined), and between regions 

 for Atlantic cod. T-tests were used to compare mean percent difference' in oocyte diameter between experimental and control 

 (formalin) treatments among species, t = ^statistic, df = degrees of freedom, * = statistically significant at the appropriate Bon- 

 ferroni adjusted a-value. 



' Defined by the following: iTreatmentDiameter-FormalinDiameter) x 100), where TreatnientDiameter = the mean oocyte diameter of a subsample 

 of an ovary preserved in one of the experimental treatments and FormalinDiameter - the mean oocyte diameter of a subsample of the same ovary 

 preserved in the formalin treatment. 



'^ a-values lower than 0.05 were adjusted by the sequential Bonferroni procedure for multiple comparisons iQuinn and Keough. 2002). 



(mean = -18.43). Of the four experimental treatments, 

 the split-formalin treatment produced the smallest mean 

 %4oofor GB cod (mean=-0.31), GOM cod (mean=2.90), 

 GB and GOM cod combined (mean=1.41), and haddock 

 (mean=0.77). Plaice samples in the split-formalin treat- 

 ment also exhibited only a small change (mean=-2.59), 

 but the smallest change (mean=0.94) was in the ethanol 

 treatment. 



Mean "Jc^qd was not significantly different between 

 cod and haddock for any treatment (Table 3), regard- 

 less of whether haddock samples were compared with 

 cod samples restricted to GB or when cod from GB and 

 GOM were combined. Mean %4q^ was significantly dif- 

 ferent between cod and plaice for all treatments, also 

 regardless of whether cod samples were restricted to GB 

 or when all cod were combined. There was a significant 

 difference in mean "Jc^qd for cod from GB and cod from 

 the GOM in the Gilson's (P<0.001, a=0.013), freez- 

 ing (P<0.001, a=0.025), and split-formalin (P=0.001, 



«= 0.017) treatments, but not the ethanol treatment 

 (P=0.08, «=0.05). 



In the comparison between lobe-formalin and subfor- 

 malin samples, analyses showed time preserved could 

 not have caused the difference in preserved weight be- 

 tween these groups. Although significant differences 

 in %4iv, of subsamples were detected between cod and 

 plaice in the Gilson's, ethanol, and freezing treatments, 

 time preserved between species was consistent for all 

 treatments. 



There were only five comparisons where it was appro- 

 priate to investigate time preserved as a possible cause 

 for differences in %^qd between two groups. These com- 

 parisons were the following: cod from GB and GOM in 

 the Gilson's, freezing, and split-formalin treatments, 

 and cod (GB and GOM combined) and plaice, in the 

 Gilson's and freezing treatments. The i/g that mean 

 %^QO of group preserved longer S mean %4q£, of group 

 preserved shorter was only rejected in the comparison 



