The native South American crayfishes (Crustacea, Parastacidae): state of knowledge and conservation status

Abstract

South America is considered a world biodiversity hotspot, especially for freshwater ecosystems where there is significant biodiversity and endemism across different taxonomic groups. Native South American crayfishes are characterized by small range distributions, high levels of endemism and specific habitat requirements. Although this group may be considered one of the most threatened among South American freshwater crustaceans, IUCN Red List assessments for most of these species are ‘data deficient’. IUCN assessments are technical evaluations of species risk of extinction based on biological indicators of population features, thereby providing a ‘conservation status’ for each species based on common and international standards. Attempts to assess the conservation status of native South American crayfishes have been limited mainly owing to a lack of fundamental data and also misinterpretations of present information. Thus, a revision of the state of knowledge of native South American crayfishes (taxonomy, phylogeny and distribution, genetics, ecology and threats) was carried out coupled with IUCN assessments of conservation status. Globally, the lack of information on the biology of these species is still the major obstacle to making reliable conservation status assessments. For this reason, the Data Deficient (DD) category is still appropriate for many species. However, based on the Extent of Occurrence (EOO) and severely fragmented populations, number of locations and decline in area, extent or quality of habitat, it is recommended that some species (especially Virilastacus spp.) should be moved to threatened categories (VU, EN or CR). The data suggest that others are appropriately in the Near Threatened (NT) category, because they almost reach the thresholds for threatened categories. The assessment of conservation status is essential to support future conservation actions, especially for species allocated to threatened categories. This study has identified new species under threat and also areas for future study to provide relevant data for conservation assessment for ‘data deficient’ species. Copyright © 2014 John Wiley & Sons, Ltd.

Crayfish plague in Japan: A real threat to the endemic Cambaroides japonicus

“…astaci -carriers, such as P . clarkii , in some regions of South America, including Argentina, Brazil, Colombia and Ecuador [ 28 , 29 ]. Other biogeographical regions of key importance for crayfish biodiversity, such as Japan, which possesses an endemic crayfish species, Cambaroides japonicus De Haan 1841, are also threatened by invasive North American crayfish species.…”

Current state of knowledge on Virilastacus species (Crustacea, Decapoda, Parastacidae)

“…The Ministerio de Medio Ambiente (2013a) described it as Vulnerable, in accordance with the B1ab (iii) + 2ab (iii) criteria of the IUCN Red List (2001). Finally, Almerao et al (2014)…”

“…Rudolph & Crandall ( 2007) classified V. retamali as an Endangered throughout its entire geographic range, given that it would meet the B1 ab(iii) criteria of the IUCN ( 2001) Red List for this category. Nevertheless, Buckup (2010c) classified it as Data Deficient, while Almerao et al (2014) supported the endangered species classification of Rudolph & Crandall (2007).…”

Growth of the burrowing crayfish Parastacus nicoleti (Philippi, 1882) (Crustacea, Decapoda, Parastacidae)

“…In spite of this lack of knowledge, some authors have classified this species according to the conservation categories established by the IUCN (2012) considering, for this purpose, the degradation of its natural environment due to anthropic action, as the main threat to its conservation. Thus, Bahamonde et al (1998) and Rudolph and Crandall (2005; classified it as Vulnerable (VU); Buckup (2010) and Almerão et al (2015) as Data deficient (DD); and the Ministerio del Medio Ambiente de Chile (MMA, 2013) (Ministry of the Environment), as Least Concern (LC). These different categorizations reveal the need for additional studies, especially with regard to the population ecology and reproductive biology in order to achieve a more precise evaluation.…”