Pseudobatos horkelii, Brazilian Guitarfish

• Autores: Pollom, R.; Barreto, R.; Charvet, P.; Chiaramonte, Gustavo Enrique; Cuevas, J. M.; Herman, K.; Martins, M. F.; Montealegre Quijano, S.; Motta, F.; Paesch, L.; Rincon, G.
• Año de publicación: 2020
• Idioma: inglés
• Tipo de recurso: artículo
• Materia: Chondrichthyes; Rhinopristiformes; Rhinobatidae; Brazilian Guitarfish
• Institución: Consejo Nacional de Investigaciones Científicas y Técnicas

The Brazilian Guitarfish (Pseudobatos horkelii) is a small (to 138 cm total length) shark-like ray that occurs in the Southwest Atlantic from Rio de Janeiro, Brazil, to northern Argentina. It is demersal on soft substrates of the continental shelf inshore to 150 m depth. It is captured in intense and largely unmanaged commercial and artisanal demersal trawl, gillnet, longline, and beach seine fisheries throughout its geographic range. There are three estimates of population reduction. First, in Rio Grande do Sul, total landings increased from 842 t in 1975 to 1,804 t in 1984 and then declined continuously to 157 t in 2001, the equivalent of a >99% reduction over three generations (55.5 years). Second, the average research trawl catch-per-unit-effort of Brazilian Guitarfish in southern Brazil over the years 1993 to 1999 was 17% of that observed during 1975 to 1986, also the equivalent of a >99% reduction over three generations. Fisheries remain intense and unmanaged there. Third, in Uruguay, this guitarfish is captured frequently in gillnets and longlines, is landed, and is sometimes targeted, and it is also captured in artisanal trawl fisheries. Catches from research trawls there in the 1980s and early 1990s were on average around 1,400 kg/hr, and between 2013 and 2017 were only 480 kg/hr, the equivalent of a >92% reduction over three generations. In Argentina, it is suspected that intense and inadequately managed gillnet fishing pressure has led to declines in abundance there as well. Overall, due to intense and inadequately managed fishing pressure throughout its range, and steep population declines, it is inferred that the Brazilian Guitarfish has undergone a population reduction of >80% over the past three generations (55.5 years), and it is assessed as Critically Endangered A2bd.
Fil: Pollom, R.. University Fraser Simon; Canadá
Fil: Barreto, R.. Instituto Chico Mendes de Conservacao Da Biodiversidade; Brasil
Fil: Charvet, P.. Universidade Federal do Paraná; Brasil
Fil: Chiaramonte, Gustavo Enrique. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia". Estación Hidrobiológica de Puerto Quequén (sede Quequén); Argentina
Fil: Cuevas, J. M.. Wildlife Conservation Society; Estados Unidos
Fil: Herman, K.. Georgia Aquarium; Estados Unidos
Fil: Martins, M. F.. Universidade Federal Do Rio Grande.; Brasil
Fil: Montealegre Quijano, S.. Universidade Federal de Sao Paulo; Brasil
Fil: Motta, F.. Universidade Federal de Sao Paulo; Brasil
Fil: Paesch, L.. Dirección Nacional de Recursos Acuáticos; Uruguay
Fil: Rincon, G.. Universidade Federal Do Maranhao.; Brasil