2 literature references:

Author: International Union for Conservation of Nature and Natural Resources (IUCN)
Year: 1994
Title: 1994 IUCN red list of threatened animals.
Source: International Union for Conservation of Nature and Natural Resources, Gland, Switzerland and Cambridge, U.K.
Author: FAO-FIES
Year: 2010
Title: Aquatic Sciences and Fisheries Information System (ASFIS) species list.
Source: Retrieved from http://www.fao.org/fishery/collection/asfis/en, March 2010.