2.5. Statistical analysis
All statistical analyses were conducted using SPSS 17 for Windows
(© SPSS Inc.); the results were considered statistically significant ifpb0.05. Residual plots were analysed for normal distribution of data
and homogeneity of variances. Independent sample t-tests were
used to compare the intensity of epitheliocystis, and size of cysts in
different cohorts, and to compare the levels of osmolality and lysozyme
activity between fish with or without epitheliocystis. A
chi-square goodness of fit was applied to test the equality of
epitheliocystis presence in different tank locations. As the sampling
was opportunistic, the design could not be balanced. Biological information
of the fish from cohort B was not included for statistical analyses
due to the small sample size. Associations between the levels of
lysozyme activities, osmolality and presence of epitheliocystis were
examined using a bivariate Pearson's correlation test. All sampled
fish were included in the correlation analyses