Populations analysis of the Brazilian Sharpnose Shark Rhizoprionodon lalandii (Chondrichthyes: Carcharhinidae) on the São Paulo coast, Southern Brazil: inferences from mt DNA sequences

Abstract

Sharks of the genus Rhizoprionodon can be considered some of the most important predators along the trophic coastal marine ecosystems and represent an important economic resource for the small-scale fisheries, especially on the Brazilian coastline. In order to analyze the population structure of the shark Rhizoprionodon lalandii of São Paulo, Southeastern coast of Brazil, levels of genetic diversity were identified by nucleotide sequence analyses of the mitochondrial DNA control region. The results obtained from this study present moderate values of haplotype diversity and low nucleotide diversity. Although the AMOVA tests (Φ ST = 0.08394, P < 0.01) had shown slightly differences among the studied samples, evidence for the occurrence of population structuring was not found, which may be a general feature of sharks living in coastal areas.Tubarões do gênero Rhizoprionodon são considerados predadores de grande importância ao longo da cadeia trófica nos ecossistemas costeiros e marinhos, também representando um importante recurso econômico para a pesca, especialmente no litoral brasileiro. A fim de analisar a estrutura populacional do tubarão Rhizoprionodon lalandii no litoral de São Paulo, sudeste do Brasil, foram identificados os níveis de diversidade genética a partir da análise de sequências nucleotídicas da região controladora do DNA mitocondrial. Os dados obtidos neste estudo apresentam valores moderados de diversidade haplotípica e baixos índices de diversidade nucleotídica. Embora os testes de AMOVA (Φ ST = 0,08394, P < 0,01) tenham revelado uma pequena diferença entre as amostras estudadas, evidências sobre a ocorrência de estruturação populacional não foram encontradas o que pode representar uma característica geral para tubarões vivendo em áreas costeiras.

Phylogeography and genetic population structure of Caribbean sharpnose shark Rhizoprionodon porosus

“…Partial sequences of the mitochondrial control region were isolated with primers (F-5 0 CTC CCA AAG CCA AGA TTC TG-3 0 and R-5 0 GGC TTA GCA AGG TGT CTT CTT GG-3 0 ) as shown in Mendonça et al (2009). The final primer concentrations were 5 lM, and amplifications were performed by PCR in a total volume of 25 lL with 0.8 mM dNTPs, 1.5 mM MgCl 2 , Taq DNA buffer (Tris-HCl 20 mM pH 8.4 and KCl 50 mM) and 1 U Taq Polymerase (Invitrogen) for 35 cycles (30 s at 95°C, 30 s at 55°C, and 60 s at 72°C).…”

“…Despite the large number of phylogeographic studies published during the last two decades, investigations into the genetic relatedness and evolutionary histories of shark populations remain unclear (Keeney and Heist 2006). Previous genetic investigations focused on the restricted portion of the geographic range of sharks (Keeney et al 2005;Keeney and Heist 2006;Schultz et al 2008;Mendonça et al 2009), while others investigated global assessments (Pardini et al 2001;Schrey and Heist 2003;Castro et al 2007;Chabot and Allen 2009;Portnoy et al 2010). As a result, explanations are still lacking for the widespread historical distribution of coastal sharks.…”

Biology of Rhizoprionodon lalandii (Elasmobranchii: Carcharhinidae) captured by the artisanal fishery of Margarita Island, Venezuela

“…Sin embargo, nueva información relevante ha sido generada en Brasil (Mota et al, 2005;Andrade et al, 2008;Lessa et al, 2009;Macedo et al, 2012;Mendonça et al, 2009;Bornatowsky et al, 2012;Mendonça et al, 2013), Colombia (Martinez et al, 2012) y Venezuela, por lo que se sugiere reevaluar el estato de conservación actual de la especie.…”

“…Existen diversos estudios sobre la especie en Brasil que incluyen aspectos sobre su biología reproductiva (Ferreira, 1988;Lessa, 1988;Menni & Lessa, 1998;Motta, Namora, Gadig, & Braga, 2007;Andrade, Silva-Junior, & Vianna, 2008;Macedo, Sousa, & Batista, 2012;Martínez, Álvarez, & Acero, 2012), genética (Mendonça, Oliveira, Gadig, & Foresti, 2009;2013), proporción sexual, frecuencia de longitudes, relación longitud-peso (Motta, Gadig, Namora, & Braga, 2005), edad y crecimiento (Lessa, Santana, & Almeida, 2009) y aspectos alimentarios (Lima, Daros, Mazzoleni, & Hostim-Silva, 2000;Bornatowsky, Heithaus, Albilhoa, & Corrêa, 2012). En contraste, en Venezuela a pesar de que hace más de 50 años que se reconocen sus capturas en las pesquerías (Méndez-Arocha 1963;Ginés et al1972), la información disponible sólo abarca una descripción general de la especie realizada por Cervigón & Alcalá (1999) y la relación longitud-peso para ejemplares capturados en Isla Margarita (Tagliafico, Rago, & Rangel, 2014).…”

Species delimitation in sharpnose sharks (genus Rhizoprionodon) in the western Atlantic Ocean using mitochondrial DNA

“…Amplification reactions of the cytochrome oxidase gene subunit I (COI) were carried out using the primers F1 5 0 -TCA ACC AAC CAC AAA GAC ATT GGC AC-3 0 and R1 5 0 -TAG ACT TCT GGG TGG CCA AAG AAT CA-3 0 , described by Ward et al (2005). Amplifications of the D-loop were carried using the primers D-loop F 5 0 -CTC CCA AAG CCA AGA TTC TG-3 0 and D-loop R 5 0 -GGC TTA GCA AGG TGT CTT CTT GG-3 0 described by Mendonça et al (2009b). Those amplifications were carried out in a PCR thermal cycler using 25 ll of solution 0.8 mM of dNTP, 1.5 mM of MgCl 2 , enzyme buffer Taq DNA polymerase (Tris-HCl 20 mM pH 8.4 and KCl 50 mM), 1 unit of enzyme Taq Polymerase (Invitrogen) and 0.5 mM ng of primers.…”