Crabs are crustacea of significant nutrition and medicinal values, with many species inhabiting aquatic and terrestrial environment. Further exploration of vast region of the globe could reveal many more species than already identified. Gradient of species richness could be evident from mangrove forest through savanna to desert region with perennial water source. Freshwater crabs are sensitive to pollution silting and deforestation, which some time result in redistribution outside natural habitats. Dramatic change in habitat could lead to rapid decline in population. Some threatening conditions such as agriculture, housing and industrial development have tampered with rich diversity of species in most habitats around the globe. Habitat restriction due to environmental degradation could be a major threat to local population and species diversity. Monitoring of the population and integrity of range and identification of threatened species are worthwhile conservation efforts. Land utilization for various economic purposes should however be in agreement with recruitment conditions of endangered species. Conservation strategy might also consider such biological aspects that promote reproduction and cultivation of the crab species.