My two separate response (dependent) variables are counts of two mesopredator grouper species on coral reefs. I have tried various models (LM, GLM Poisson and Gaussian and zinf and zinb) both with untransformed response variables and with square root transformed response variables.
The best fit model for one species (due to the distribution of the data) is a Gaussian GLM with square root transformed counts and for the other species is a zero-inflated Poisson model with untransformed counts.
Is it appropriate to use different models if I want to compare the effects of the explanatory variables on each of the species?
If not, which model can I use to fit both species count data?