Fish Ecologists,
I am analysing my Data on three small haplochromine fish species from
Lake Malombe -Malawi. I have used Shannon -Weiner Diversity Index
to compare the species diversity of the two sites. However, I do not
know the best way of testing statistical differences. Should I use
Student t- test or Mann Whitney test?  Researchers have used both of
tests but which is most suitable for tropical freshwater lakes?

Collins.