DNA Barcoding and Species Delimitation for Dogfish Sharks Belonging to the <i>Squalus</i> Genus (Squaliformes: Squalidae)
Ailton A. Ariza,
Aisni M. C. L. Adachi,
Pollyana Roque,
Fabio H. V. Hazin,
Marcelo Vianna,
Matheus M. Rotundo,
Sergio M. Delpiani,
Juan M. Díaz de Astarloa,
Gabriela Delpiani,
Claudio Oliveira,
Fausto Foresti,
Vanessa P. Cruz
Affiliations
Ailton A. Ariza
Laboratório de Biologia e Genética de Peixes, Instituto de Biociências de Botucatu, Universidade Estadual Paulista, Botucatu 18618-689, Brazil
Aisni M. C. L. Adachi
Laboratório de Biologia e Genética de Peixes, Instituto de Biociências de Botucatu, Universidade Estadual Paulista, Botucatu 18618-689, Brazil
Pollyana Roque
Laboratório de Oceanografia Pesqueira, Universidade Federal Rural de Pernambuco, Recife 52171-900, Brazil
Fabio H. V. Hazin
Laboratório de Oceanografia Pesqueira, Universidade Federal Rural de Pernambuco, Recife 52171-900, Brazil
Marcelo Vianna
Laboratório de Biologia e Tecnologia Pesqueira, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-901, Brazil
Matheus M. Rotundo
Acervo Zoológico da Universidade Santa Cecília, Universidade Santa Cecília, Santos 11045-907, Brazil
Sergio M. Delpiani
Grupo de Biotaxonomía Morfológica y Molecular de Peces, Departamento de Biología, Facultad de Ciencias Exactas y Naturales, Instituto de Investigaciones Marinas y Costeras, Funes 3250, Mar del Plata 7600, Argentina
Juan M. Díaz de Astarloa
Grupo de Biotaxonomía Morfológica y Molecular de Peces, Departamento de Biología, Facultad de Ciencias Exactas y Naturales, Instituto de Investigaciones Marinas y Costeras, Funes 3250, Mar del Plata 7600, Argentina
Gabriela Delpiani
Grupo de Biotaxonomía Morfológica y Molecular de Peces, Departamento de Biología, Facultad de Ciencias Exactas y Naturales, Instituto de Investigaciones Marinas y Costeras, Funes 3250, Mar del Plata 7600, Argentina
Claudio Oliveira
Laboratório de Biologia e Genética de Peixes, Instituto de Biociências de Botucatu, Universidade Estadual Paulista, Botucatu 18618-689, Brazil
Fausto Foresti
Laboratório de Biologia e Genética de Peixes, Instituto de Biociências de Botucatu, Universidade Estadual Paulista, Botucatu 18618-689, Brazil
Vanessa P. Cruz
Laboratório de Biologia e Genética de Peixes, Instituto de Biociências de Botucatu, Universidade Estadual Paulista, Botucatu 18618-689, Brazil
The Squalus genus comprises a group of small demersal sharks occurring circumglobally, popularly known as dogfish sharks. This genus exhibits a conserved morphology, thus making correct morphological identification difficult. Considering these taxonomic problems and the scarcity of molecular data, the present study aimed to identify Squalus genus MOTUs, using DNA barcoding for species delimitation via ABGD (automatic barcode gap discovery), PTP (Poisson tree process), and GMYC (general mixed Yule coalescent) employing the mitochondrial COI gene. A total of 69 sequences were generated from samples obtained from the American coast in both the Atlantic and Pacific Oceans. The ABGD analysis was the most conservative among the three applied delimitations, indicating three taxonomic units, while the PTP analysis revealed nine MOTUs, with two conflicting units noted between S. clarkae + S. mitsukurii and S. albicaudus + S. cubensis. The GMYC analysis indicated an excessive division, with S. acanthias and S. mitsukurii subdivided into six MOTUs each and S. blainville, into four. These findings demonstrated that Squalus presents a complex of previously defined species, with misidentified samples deposited in databases leading to difficulties in analyzing the real distribution and diversity of species belonging to this genus. Thus, further efforts to highlight possible new species are recommended.