5 research outputs found
Genetic diversity in two threatened species of guitarfish (Elasmobranchii: Rhinobatidae) from the Brazilian and Argentinian coasts: an alert for conservation
The guitarfishes Pseudobatos horkelii and Pseudobatos percellens meet the criteria for threatened status as Critically Endangered (CR) and Endangered (EN), respectively. Both species occur in the Southern Atlantic Ocean. Considering the lack of data on the genetic structure of these species, the present study evaluated the genetic variability and population structure of the P. horkelii and P. percellens in the southern region of Brazil and the northern coast of Argentina, based on sequences of mitochondrial DNA, Control Region (D-loop). Samples of P. horkelii (n = 135) were analyzed in six localities situated in Northern Argentina, along the Brazilian states’ coast. The mean of nucleotide diversity was 0.0053, the ΦST was 0.4277 and demographic analysis of P. horkelii suggests the existence of stability of the populations, with D = 0.9929, FS = 2.0155, SSD = 0.0817, R = 0.2153. In P. percellens (n = 101) were analyzed from six Brazilian localities along the coast of Santa Catarina, Paraná, and SĂŁo Paulo. The mean nucleotide diversity was 0.0014 and ΦST value of 0.2921, the demographic analysis indicates a high migration rate of P. percellens among the localities evaluated, with D = 0.5222, FS = 0.3528, SSD = 0.01785, R = 0.3890.As raias violas Pseudobatos horkelii e Pseudobatos percellens, sĂŁo listados como “Criticamente em Perigo” (CR) e “Em Perigo” (EN), respectivamente. Ambas as espĂ©cies ocorrem no Sul do Oceano Atlântico. Considerando a falta de dados sobre a estrutura genĂ©tica dessas espĂ©cies, o presente estudo avaliou a variabilidade genĂ©tica e a estrutura populacional de P. horkelii e P. percellens na regiĂŁo sudeste do Brasil e litoral norte da Argentina, com base em sequĂŞncias de DNA mitocondrial, regiĂŁo de controle (D-loop). Amostras de 135 indivĂduos de P. horkelii analisados em seis localidades, situadas no norte da Argentina e ao longo da costa dos estados brasileiros. A mĂ©dia da diversidade nucleotĂdica foi de 0.0053, o Ăndice ΦST foi de 0.4277 e a análise demográfica de P. horkelii, indicou a existĂŞncia de estabilidade das populações, com D = 0.9929, Fus = 2.0155, SSD = 0.0817, R = 0.2153. Em 101 exemplares de P. percellens, foram analisados em seis localidades brasileiras ao longo do litoral de Santa Catarina, Paraná e SĂŁo Paulo. A diversidade nucleotĂdica mĂ©dia foi de 0.0014 e o valor ΦST de 0.2921, a análise demográfica indicou uma alta taxa de migração de P. percellens entre as localidades analisadas, com D = 0.5222, FS = 0.3528, SSD = 0.01785, R = 0.3890.Fil: Cruz, Vanessa P.. Universidade Estadual Paulista Julio de Mesquita Filho; BrasilFil: Adachi, Aisni M. C. L.. Universidade Estadual Paulista Julio de Mesquita Filho; BrasilFil: Oliveira, Pablo H.. Universidade Estadual Paulista Julio de Mesquita Filho; BrasilFil: Ribeiro, Giovana S.. Universidade Estadual Paulista Julio de Mesquita Filho; BrasilFil: Paim, Fabilene G.. Universidade Estadual Paulista Julio de Mesquita Filho; BrasilFil: Souza, Bruno C.. Universidade Estadual Paulista Julio de Mesquita Filho; BrasilFil: Rodrigues, Alexandre S. F.. Universidade Estadual Paulista Julio de Mesquita Filho; BrasilFil: Vianna, Marcelo. Universidade Federal do Rio de Janeiro; BrasilFil: Delpiani, Sergio Matias. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: DĂaz de Astarloa, Juan MartĂn. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: Rotundo, Matheus M.. Universidade Santa CecĂlia; BrasilFil: Mendonça, Fernando F.. Universidade Estadual Paulista Julio de Mesquita Filho; BrasilFil: Oliveira, Claudio. Universidade Estadual Paulista Julio de Mesquita Filho; BrasilFil: Lessa, Rosangela P.. Universidad Federal Rural Pernambuco; BrasilFil: Foresti, Fausto. Universidade Estadual Paulista Julio de Mesquita Filho; Brasi
Morphological Characters of the Thickbody Skate Amblyraja frerichsi (Krefft 1968) (Rajiformes: Rajidae), with Notes on Its Biology
Detailed descriptions of morphological features, morphometrics, neurocranium anatomy, clasper structure and egg case descriptions are provided for the thickbody skate Amblyraja frerichsi; a rare, deep-water species from Chile, Argentina and Falkland Islands. The species diagnosis is complemented from new observations and aspects such as colour, size and distribution are described. Geographic and bathymetric distributional ranges are discussed as relevant features of this taxońs biology. Additionally, the conservation status is assessed including bycatch records from Chilean fisheries
First report of the black gemfish Nesiarchus nasutus (Perciformes: Gempylidae) in Argentinean waters
The gempylid Nesiarchus nasutus is reported for the first time from Argentinean waters, the southernmost occurrence of the species in the Southwestern Atlantic. This suggests that the fluctuating environmental characteristics of the area would be proper for the presence of tropical and subtropical species
First report of the black gemfish Nesiarchus nasutus (Perciformes: Gempylidae) in Argentinean waters
The gempylid Nesiarchus nasutus is reported for the first time from Argentinean waters, the southernmost occurrence of the species in the Southwestern Atlantic. This suggests that the fluctuating environmental characteristics of the area would be proper for the presence of tropical and subtropical species