Fishers’ knowledge about fish trophic interactions in the southeastern Brazilian coast

Data derived from studies of fishers' local ecological knowledge (LEK) can be invaluable to the proposal of new studies and more appropriate management strategies. This study analyzed the fisher's LEK about trophic relationships of fishes in the southeastern Brazilian coast, comparing fishers' LEK with scientific knowledge to provide new hypotheses. The initial contacts with fishers were made through informal visits in their residences, to explain the research goals, meet fishers and their families, check the number of resident fishers and ask for fishers' consent to participate in the research. After this initial contact, fishers were selected to be included in the interviews through the technique of snowball sampling. The fishers indicated by others who attended the criteria to be included in the research were interviewed by using a semi-structured standard questionnaire. There were interviewed 26 artisanal fishers from three communities of the Ilhabela: Jabaquara, Fome and Serraria. The interviewed fishers showed a detailed knowledge about the trophic interactions of the studied coastal fishes, as fishers mentioned 17 food items for these fishes and six fish and three mammals as fish predators. The most mentioned food items were small fish, shrimps and crabs, while the most mentioned predators were large reef fishes. Fishers also mentioned some predators, such as sea otters, that have not been reported by the biological literature and are poorly known. The LEK of the studied fishers showed a high degree of concordance with the scientific literature regarding fish diet. This study evidenced the value of fishers' LEK to improve fisheries research and management, as well as the needy to increase the collaboration among managers, biologists and fishers

Cytogenotoxicity biomarkers in fat snook Centropomus parallelus from Cananéia and São Vicente estuaries, SP, Brazil

The aquatic environment receives many contaminants that can induce damages at the molecular, biochemical, cellular and physiological levels. Centropomus parallelus, an important food resource for local populations, is a predator fish that feeds on small fishes and benthic invertebrates, thus being vulnerable to the bioconcentration and biomagnification processes. This study aimed to evaluate cytogenotoxic responses in erythrocytes from C. parallelus juveniles collected in the Cananéia and São Vicente estuaries, both in winter and in summer. After anesthesia, blood samples were collected by caudal puncture. Blood smears were prepared on glass slides and stained with May-Grünwald-Giemsa dye. Two thousand cells were analyzed per slide (1000x), and nuclear abnormalities (NA) and micronuclei (MN) were scored. The São Vicente sample showed MN and NA frequencies (%/1000 cells) of 0.325 and 3.575, in winter, and of 0.125 and 2.935 in summer respectively; the Cananéia sample showed frequencies of 0.0325 and 0.03, in winter, and of 0.065 and 0.355 in summer, respectively. The rates found in São Vicente were significantly higher than those found in Cananéia, evidencing that the levels of pollution in that estuary were high enough to induce genetic damages

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 São 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, são listados como “Criticamente em Perigo” (CR) e “Em Perigo” (EN), respectivamente. Ambas as espécies ocorrem no Sul do Oceano Atlântico. Considerando a falta de dados sobre a estrutura genética dessas espécies, o presente estudo avaliou a variabilidade genética e a estrutura populacional de P. horkelii e P. percellens na região sudeste do Brasil e litoral norte da Argentina, com base em sequências de DNA mitocondrial, região de controle (D-loop). Amostras de 135 indivíduos de P. horkelii analisados em seis localidades, situadas no norte da Argentina e ao longo da costa dos estados brasileiros. A média da diversidade nucleotídica foi de 0.0053, o índice ΦST foi de 0.4277 e a análise demográfica de P. horkelii, indicou a existência 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 São Paulo. A diversidade nucleotídica média 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 Científicas y Técnicas. Centro Científico Tecnológico 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: Díaz de Astarloa, Juan Martín. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico 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 Cecília; 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

Etnoecologia da pesca de camarões usados como isca viva na Barra do Una, Peruíbe (SP/ Brasil)

Um grande número de espécies de peixes e crustáceos são capturados pela pesca artesanal em ambientes lacustres, rios, córregos, estuários, suprindo as necessidades de proteína animal para as populações que habitam estes ambientes. Entre os crustáceos, o camarão é um recurso de grande importância comercial e nutricional, além de ser utilizado como isca viva, especialmente para a pesca esportiva. O presente estudo teve como objetivo realizar um levantamento etnoecológico e caracterizar a pesca de camarão para venda de isca viva em uma comunidade caiçara do Mosaico Juréia-Itatins, Peruíbe, Estado de São Paulo. Os dados foram coletados por meio de entrevistas etnoecológicas e identificação taxonômica dos recursos explorados. Durante as entrevistas foram questionadas informações sobre as técnicas de captura e armazenamento dos recursos, formas de comercialização, entre outros. Os dados foram analisados por meio da construção de tabelas de cognição comparados pelo qual tanto o conhecimento científico como local foram combinados. Um total de 38 pescadores foram entrevistados, que capturam o camarão para o consumo, o comércio (lojas de peixe, bares e restaurantes), e vendem principalmente isca viva para a pesca esportiva. As principais espécies capturadas e usadas como isca são o “pitu” (Macrobrachium acanthurus), o “camarão-branco” (Litopenaeus schmitti), e o “camarão-sete-barbas” (Xiphopenaeus kroyeri). O estudo destaca o amplo conhecimento dos pescadores de Barra do Una sobre hábitos de vida, habitat, dimorfismo sexual e interações interespecíficas de espécies de camarão usados como isca. Além disso, outras informações registradas incluem os recursos pesqueiros utilizados, métodos de captura, uso de iscas de pesca, biologia dos peixes e outros crustáceos. O conhecimento destes pescadores está de acordo com a literatura, demonstrando a importância da etnoecologia, a fim de formular planos de gestão ambiental visando à sustentabilidade da pesca e valorização das comunidades locais

DNA Barcoding and Species Delimitation for Dogfish Sharks Belonging to the <i>Squalus</i> Genus (Squaliformes: Squalidae)

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

DNA Barcoding and Species Delimitation for Dogfish Sharks Belonging to the Squalus Genus (Squaliformes: Squalidae)

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

DNA barcoding reveals deep divergent molecular units in Pomatomus saltatrix (Perciformes: Pomatomidae): implications for management and global conservation

Pomatomus saltatrix is a high-value marine pelagic coastal fish, that is fished throughout subtropical and temperate coastal waters around the world. Despite its large economic potential, there are no global data on its genetic diversity, which could compromise the conservation of the species. The aim of this study was to analyse the genetic-evolutionary structuring of the species, with the intention of evaluating different genetic P. saltatrix stocks that may indicate potential species. Based on 157 Cytochrome C Oxidase Subunit 1 sequences, the molecular delimitation analyses of species (distance and coalescence methods), as well as the haplotype network, found profound geographic structuring related to five distinct units with high and significant FST pairwise values. The divergence of these molecular units is mostly related to the Pleistocene glacial and interglacial cycles of climatic oscillations. It is hypothesized that one ancestral lineage, adapted to cold water environments, diversified into two lineages, with one more adapted to warmer environments. The high values of global genetic diversity (π = 0.016; h = 0.96) may be related to the existing profound genetic differentiation. Due to the presence of five Molecular Operational Taxonomic Units (MOTUs) within the species it is necessary to employ different regional management strategies. Traits of low haplotype richness and shallow population contraction were identified in the MOTUs V (Venezuela and Brazil) and III (Turkey and Australia), respectively, representing conservation priorities. Other molecular markers, as well as morphological data, should be explored with the aim of defining the taxonomic status of P. saltatrix stocks.Fil: de Queiroz Brito, Maria Clara G.. Universidade Federal de Pernambuco; BrasilFil: Barros Machado, Carolina. Universidade Federal do São Carlos; BrasilFil: Gama Maia, Danielle de Jesus. Universidade Federal do Rio de Janeiro; BrasilFil: Pereira Jacobina, Uedson. Universidade Federal de Alagoas; BrasilFil: Nirchio, Mauro. Universidad de Oriente; VenezuelaFil: Rotundo, Matheus M. Universidade Santa Cecília; BrasilFil: de Almeida Tubino, Rafael. Universidade Federal Rural do Rio de Janeiro; BrasilFil: Fernandez Iriarte, Pedro Jose. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Departamento de Biología. Laboratorio de Genética; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico 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: Haimovici, Manuel. Universidade Federal do Rio Grande; BrasilFil: Torres, Rodrigo Augusto. Universidade Federal do Paraná; Brasi