I've searched around CV for a bit, and have not found a good answer as to what test to use instead of multiple t-tests in my particular situation.
I am interested in comparing mean size (of fish) between two habitat types for 20 different species. For each species, I want to know if fish are larger on one habitat type vs the other. I do not care about the relationship between species (I know that some species are bigger than others), and so ANOVA has not seemed appropriate. It seems that I could do 20 t-tests to see if some species are larger in one habitat over the other- or perhaps there is a simpler (or more statistically sound) approach?
If I were to go with t-tests, would this be a case of multiple comparisons, even though the species are independent of one another?