The conservation status of hypogean fishes

Synopsis

Hypogean fishes are susceptible to five main threats: habitat degradation, hydrological manipulations, environmental pollution, overexploitation, and introduced alien species. Because they are endemic to small areas and have small populations, any threat could have serious consequences. For these reasons most populations have been considered ‘threatened’ or ‘vulnerable’. International Union for the Conservation of Nature, and Natural Resources has produced five Red Lists of threatened animals since 1977 and have listed seven, eight, 31, 31 and 63 hypogean fishes, respectively, in some threat category. Before 1994 the categories were qualitative and workers could assess the same species in different ways. In 1994, a new set of quantitative categories were published. The 1996 list was the first to use these categories and three hypogean species were listed critically endangered, two endangered, 46 vulnerable and 12 data deficient. Some of these categories are incorrect or inappropriate and most of the data deficient ones can now be categorised. All 85 known species are categorised here and reasons given for their placements. The current list has three critically endangered, none endangered, 73 vulnerable, four near threatened, one least concern and four data deficient. Some species are relatively well known, others are poorly known. Some are receiving conservation attention, most receive none. A few captive populations have been established, some of which are breeding. Few populations could be restocked if extirpated. Knowing where to direct conservation efforts is a problem since morphological ‘species’ are proving to be from more than one epigean invasion and therefore represent more than one species. Hypogean fishes merit protection but they may not receive more than cursory protection.