The geographic history of Madagascar (long isolated, but part of Gondwana) has resulted in unusual biogeographic patterns, comparable to those seen in other animal and plant groups of the island.
The freshwater fish fauna in Madagascar has declined drastically due to habitat loss (pollution, siltation following deforestation, damming and alike), overfishing and introduced species (tilapia, Nile perch, African arowana, blotched snakehead, green swordtail and many other), with some suggesting that only a remnant of the natives can be saved [REF].