There are possibly turtles of the generae Pelusios, Pelomedusa, and Softshell[ Cycloderma, Trionyx, etd.] located there. All of them will attack and devour fish. Trionyx triunguis reaches weights in excess of 100 lbs and eats anything from small crocodiles to fish. All of the smaller species are very ordinary brown looking turtles. Just get something you like that will co-habitate with the fish. thanks