Diversity, distribution and conservation of freshwater crabs and shrimps in South America.

Abstract

South America has a huge diversity of freshwater decapods that occupy a variety of ecosystems including major rivers, lakes, wetlands, and mountain streams. Although large areas of the continent’s freshwater ecosystem are still pristine and well preserved, many decapod species are increasingly impacted by different anthropogenic threats. This chapter focuses on the warm-water freshwater decapods found in the tropical and subtropical regions of South America that include the freshwater crabs (2 families, 34 genera, 209 species) and the freshwater shrimps (5 families, 11 genera, 88 species). The most species rich country for freshwater crabs is Colombia (105 species), followed by Brazil (49 species), and Venezuela (46 species), while the most species rich-country for freshwater shrimps is Venezuela (36 species), followed by Brazil (35 species), and Colombia (30 species). IUCN Red List conservation assessments have been carried out recently on a global scale for both freshwater crabs and shrimps, but national level assessments have so far only been made for the 76 species of Brazilian decapods, which found no threatened species in that country, and only one shrimp, Atya scabra, to be Near Threatened. Comparisons of national and regional assessments with the IUCN global assessments in some South American countries are made, and recommendations for freshwater decapod research in the region are offered.