SHARK NEWS SHARK NEWS 14 NEWSLETTER OF THE IUCN SHARK SPECIALIST GROUP MARCH 2002 South & Central America issue also includes ... Conversations with a former sawfish fishermen Molecular genetics of some Brazilian sharks Artisanal ray fishery in the Gulf of California Shark Specialist Group web site: http://www.flmnh.ufl.edu/fish/Organizations/SSG/SSGDefault.html Historic trends in catches of the Brazilian longline fishery Elasmobranch bycatch in the Chilean deep sea crustacean fishery Next issue: Elasmobranchs in Aquaria Fisheries Historically, freshwater stingrays were not valuable to Amazon fishermen as food fish (Ferreira 1886). Nonetheless, these rays are routinely captured as a food resource in some regions of the lower Amazon drainage. In addition, during the last 15 years they have become important as ornamental fish, comprising 1 % of the total ornamental fish exports from Manaus (Amazonas State), with at least six species regularly exported for this purpose. Potamotrygon motoro, P. orbignyi, P. schroederi, P. leopoldi, P. henlei and Potamotrygon sp. comprise 67% of all freshwater stingrays exported from Manaus, and the latter three species are endemic to areas where gold mines, dams, and large ecotourism projects are in progress. Twenty thousand freshwater stingrays are now exported annually from Brazil. Around 57 % are from the Rio Negro Basin (Amazonas State). Despite this demand, the Brazilian Environmental Agency (IBAMA) has no fishery or exportation records for these species from this area. Specimens from other areas are often incorrectly identified and export numbers are certainly underestimated. Nowadays, P. leopoldi and P. henlei are in fact illegally exported from Brazil. Some other species, from the Amazonas State, are being exported according to law number 022/98 (IBAMA 2001) that establishes a quota system for each export authorised species. The most important countries involved in the Potamotrygonidae trade are the United States, Japan, Taiwan and Germany, where these stingrays are sold in pet shops according to codes that represent a particular colour pattern rather than a species. Accidents involving freshwater stingrays are common in most Amazon Basin rivers. Painful results of these accidents certainly make these stingrays extremely non-charismatic and feared animals for local residents and visitors. It has been estimated that in the last three years at least 21,000 stingrays have been removed from the population as a direct result of the tourism industry, with agencies hiring people to “clean- up” the river beaches by killing the stingrays prior to the arrival of tourists. Mutilation of specimens has also been observed. Unfortunately, given that the removal of stingrays in this way does not represent “fishing” as such, IBAMA has been unable to control it. Case study of the Tucuruí Dam The present Brazilian electrical crisis and the subsequent demand for the construction of hydroelectric powerplants has raised questions about the effects of dams on freshwater fishes, especially stingray Neotropical Freshwater Stingrays: diversity and conservation status Patricia Charvet-Almeida 1 , Maria Lúcia Góes de Araújo 2 , Ricardo S. Rosa 3 and Getúlio Rincón 4 1 MPEG, Belém; 2 UA, Manaus; 3 UFPB, João Pessoa; 4 UNESP, Rio Claro, Brazil (the authors’ name sequence does not indicate priority in the contribution to this article). Diversity The family Potamotrygonidae, Garman 1877 is comprised of freshwater stingrays with geographical distribution restricted to South America. They occur in several river basins draining into the Atlantic Ocean, and a few species enter estuarine waters. The taxonomic status of the group has been subject to debate in the recent literature, with some authors regarding it as a monophyletic family (Thorson et al. 1983, Rosa et al. 1987, Lovejoy 1996), while others treat it as part of the Dasyatidae, either as a subfamily (Nelson 1994) or as a paraphyletic assemblage (Nishida 1990). The taxonomic composition of the Potamotrygonidae was revised by Rosa (1985), who reported 32 species clearly assigned to this family, 20 of which were considered valid species in three distinct genera, namely Plesiotrygon, Potamotrygon and Paratrygon. This taxonomic arrangement has been followed by subsequent authors (Eschmeyer 1998, Compagno 1999) although Rosa and others have presented evidence of several undescribed species (Rosa 1985, Carvalho 2001), and of at least one undescribed genus (Ishihara and Taniuchi 1995, Compagno 1999, Charvet-Almeida and Rosa 2001). Potamotrygon leopoldi, searching for food in its natural habitat. This is one of the most valuable species in the ornamental fish market. Photo: Patricia Charvet-Almeida.