Folk taxonomy of the gray mullets (Mugilidae: Mugiliformes) in a marine extractivist reserve of northern Brazil

Fish local knowledge is important to recognize species and contribute to conservation and management strategies. Thus, our aim was to provide diagnostic information for the rapid identification of Mugilidae species in Caeté-Taperaçu Extractive Reserve in Bragança (PA) in northern Brazil. A total of 28 fishers were interviewed using semi-structured questionnaires. Most of the interviewees have lived in their resident village since birth and have been involved in artisanal fishers for at least 12 years. Eight generic folk taxa were identified, including 'tainha', which was the vernacular name most used to define the Mugil genus. Each scientific species had at least two folk generic taxa and one species. Mugil curema, M. rubrioculus, and M. trichodon were all included in the same ethnospecies, 'tainha chata'. Most of the scientific species were referred to at least once as the ethnospecies 'caica', this name was applied most often to Mugil brevirostris, which is the smallest species found in northern Brazil. The principal characteristics used by the fishers were morphological traits, however, some behavioral characteristics were also taken into account. These findings should contribute to the elaboration of ethnotaxonomic keys that facilitate the rapid identification of Mugil harvested by the region's artisanal and industrial fisheries.(AU)

O conhecimento local sobre peixes é importante para reconhecer espécies e contribui para estratégias de conservação e manejo. Nosso objetivo foi fornecer informações diagnósticas para a rápida identificação das espécies de Mugilidae da região da Reserva Extrativista Marinha Caeté Taperaçu (PA), Norte do Brasil. Um total de 28 pescadores foi entrevistado por meio de questionários semiestruturados. A maioria dos entrevistados vive na sua aldeia residente desde o nascimento e está envolvida na pesca artesanal há pelo menos 12 anos. Oito táxons populares genéricos foram identificados por esses pescadores, incluindo 'tainha', que era o nome vernacular mais usado para definir o gênero Mugil. Cada espécie científica tinha pelo menos dois táxons genéricos populares e uma espécie. Mugil curema, M. rubrioculus e M. trichodon foram todos incluídos na mesma etnoespécie, 'tainha chata'. A maioria das espécies científicas foi referida pelo menos uma vez como etnoespécie 'caica', este nome foi aplicado mais frequentemente a Mugil brevirostris, que é a menor espécie encontrada no Norte do Brasil. As principais características utilizadas pelos pescadores foram os traços morfológicos, porém, algumas características comportamentais também foram levadas em consideração. Esses achados devem contribuir para a elaboração de chaves etnotaxonômicas que facilitem a rápida identificação de Mugil capturadas pela pesca artesanal e industrial da região.(AU)

The fishery of pelagic shrimp aviú Acetes paraguayensisin eastern Brazilian Amazon / A pesca do camarão pelágico aviú Acetes paraguayensisna Amazônia oriental brasileira

The pelagic shrimp, Acetes paraguayensis Hansen, 1919, is an ecologically important species with an enormous socioeconomic value for the human populations in the regions where it occurs. This species also has considerable potential for shrimp farming, although few details are known of its biology. This study investigated the artisanal exploitation of A. paraguayensis stocks in the northern Brazilian municipality of Santarém over 16 months, focusing on the types of equipment most used to harvest of this shrimp, the fishing dynamics, and production patterns. The matapi trap was the principal method used of harvesting A. paraguayensis in the study region, conforming to a typically artisanal, small-scale fishing production system. This study results provide an essential research tool for developing conservation and management strategies and the eventual establishment of farming protocols.

O camarão pelágico, Acetes paraguayensis Hansen, 1919, é uma espécie ecologicamente importante, de enorme valor socioeconômico para as populações humanas localizadas nas regiões produtoras. Essa espécie tem também um potencial considerável para o cultivo, embora poucas informações sejam conhecidas da sua biologia. Assim o presente estudo investigou a exploração artesanal das po-pulações de A. paraguayensis no município paraense de Santarém, no Norte do Brasil, por 16 meses, concentrando-se nos tipos de equipamento mais utilizados para sua captura, na dinâmica pesqueira e nos padrões de produção. O matapi foi o principal método utilizado, configurando-se como um sistema de produção pesqueira tipicamente artesanal de pequena escala. Os resultados do presente estudo constituem importante instrumento de investigação para o desenvolvimento de estratégias de conservação e gestão e o eventual estabelecimento de protocolos de cultivo.

Multidisciplinary approach to identification of fishery systems in amazonian reservoir: case study in Tucuruí Dam / Abordagem multidisciplinar para a identificação dos sistemas pesqueiros em um reservatório amazônico: estudo de caso na Hidrelétrica de Tucuruí

Dams cause profound changes in the structure of environments and local fishing practices. One example of these impacts is the Tucuruí dam, in the southeast of the state of Pará, in northern Brazil. The changes were gradual, but eventually established unique fishery systems and capture techniques that were consolidated over time. The present study used a rapid analysis technique based on the Métier principle to identify 14 fishing systems with distinct characteristics, although a more holistic approach (dimensions: economic, social, technological, and management), supported the identification of four clearly distinguishable groups. From the management perspective, studies of this type are important because they permit the establishment of more effective practices based on the deficiencies found in the different systems or their respective groups.

As barragens causam profundas mudanças na estrutura dos ambientes e nas práticas de pesca das áreas sob sua influência. Um exemplo dessas mudanças ocorreu na barragem de Tucuruí, no sudeste do Pará, Brasil. As mudanças foram tipologias de pesca graduais e estabelecidas como formas únicas de captura que foram consolidadas ao longo do tempo. Neste documento, usando uma técnica de análise rápida baseada no princípio de métier, foram identificados 14 sistemas de pesca com características particulares, mas, com base em uma observação mais holística (dimensões ecológica, econômica, social, tecnológica e de gestão), quatro grupos de sistemas pesqueiros foram claramente definidos. Do ponto de vista do gerenciamento, estudos dessa natureza são importantes, pois permitem o estabelecimento de práticas de gerenciamento mais criativas, baseadas nas deficiências encontradas nos sistemas ou grupo de sistemas.

Multidisciplinary approach to identification of fishery systems in amazonian reservoir: case study in Tucuruí Dam / Abordagem multidisciplinar para a identificação dos sistemas pesqueiros em um reservatório amazônico: estudo de caso na Hidrelétrica de Tucuruí

Dams cause profound changes in the structure of environments and local fishing practices. One example of these impacts is the Tucuruí dam, in the southeast of the state of Pará, in northern Brazil. The changes were gradual, but eventually established unique fishery systems and capture techniques that were consolidated over time. The present study used a rapid analysis technique based on the Métier principle to identify 14 fishing systems with distinct characteristics, although a more holistic approach (dimensions: economic, social, technological, and management), supported the identification of four clearly distinguishable groups. From the management perspective, studies of this type are important because they permit the establishment of more effective practices based on the deficiencies found in the different systems or their respective groups.(AU)

As barragens causam profundas mudanças na estrutura dos ambientes e nas práticas de pesca das áreas sob sua influência. Um exemplo dessas mudanças ocorreu na barragem de Tucuruí, no sudeste do Pará, Brasil. As mudanças foram tipologias de pesca graduais e estabelecidas como formas únicas de captura que foram consolidadas ao longo do tempo. Neste documento, usando uma técnica de análise rápida baseada no princípio de métier, foram identificados 14 sistemas de pesca com características particulares, mas, com base em uma observação mais holística (dimensões ecológica, econômica, social, tecnológica e de gestão), quatro grupos de sistemas pesqueiros foram claramente definidos. Do ponto de vista do gerenciamento, estudos dessa natureza são importantes, pois permitem o estabelecimento de práticas de gerenciamento mais criativas, baseadas nas deficiências encontradas nos sistemas ou grupo de sistemas.(AU)

Biologia populacional do peixe-pedra, Genyatremus luteus (Bloch, 1790), na costa amazônica brasileira / Population biology of torroto grunt, Genyatremus luteus (Bloch, 1790), Brazilian amazonian coast

Genyatremus luteus é uma espécie de peixe de importância comercial no estado do Pará. Neste estudo foi investigada a biologia populacional de G. luteus em um estuário da Amazônia Oriental. Para tanto, realizaram-se coletas de exemplares da espécie no Furo Grande, no período de outubro de 2012 a outubro de 2013, mensalmente, com rede de emalhar tipo block-net. Em laboratório, os indivíduos foram aferidos os comprimentos total, padrão e da cabeça e a altura, além de ser registrado o peso úmido. Após incisão ventral e retirada das gônadas, macroscopicamente, definiu-se o estádio gonadal das fêmeas e dos machos. Foram capturados 460 indivíduos cujos tamanhos e pesos variaram entre 4,50 e 21,40 cm e 1,36 e 148,26 g. As frequências relativas das fêmeas e dos machos foram diferentes do esperado de 1:1 (x2: 8,90; p<0,01), diferindo significativamente por sexo e classe de tamanho (p<0,01). As médias de tamanho (CT) apresentaram diferenças significativas em relação ao sexo (F=22,71; p<0,01), mês (F=35,80; p<0,01), período sazonal (F=6,03; p<0,01), estádio gonadal (F=29,77; p<0,01) e estádio gonadal por período sazonal (F=2,37; p<0,05). O peso úmido não diferiu estatisticamente por estádio gonadal, período sazonal e sexo. O diagrama de ordenação demonstrou que a turbidez da água foi a variável que respondeu pela maior variabilidade dos dados (total de 97%). Os espécimes capturados neste estudo são pequenos em tamanho e peso e reprodutivamente imaturos, com maior ocorrência de fêmeas e em maior número no período seco.(AU)

Genyatremus luteus is specie of commercial importance in the Pará state. In this study, the population biology of G. luteus was investigated in an estuary of the Eastern Amazon, the collections occurred from October 2012 to October 2013, each month, in the tidal channel (Furo grande), with block net. In the laboratory the individuals were gauged the lengths: total, standard, head and height, in addition to weight being recorded. After ventral incision and gonads removal, the gonadal stage was defined for females and males macroscopically. 460 individuals were captured whose sizes and weights ranged from 4.50 to 21.40 cm and 1.36 and 148.26 g. The relative frequencies of females and males were different than expected from 1: 1 (x2: 8.90, p <0.01), differing significantly by sex and size class (p <0.01). The mean size (CT) presented differences significant in relation to sex (F = 22.71, p <0.01), month (F = 35.80, p <0.01) (P <0.01), gonadal stage (F = 29.77, p <0.01) and gonadal stage by seasonal period (F = 2.37, p <0.05). The wet weight did not differ statistically by gonadal stage, seasonal period and sex. The ordering diagram showed that the turbidity was the variable that responded by the greater variability in the data (total of 97%). The specimens captured in this study are small in size and weight and reproductively immature, with higher occurrence of females, in greater numbers in the dry period.(AU)

Biologia populacional do peixe-pedra, Genyatremus luteus (Bloch, 1790), na costa amazônica brasileira / Population biology of torroto grunt, Genyatremus luteus (Bloch, 1790), Brazilian amazonian coast

Genyatremus luteus é uma espécie de peixe de importância comercial no estado do Pará. Neste estudo foi investigada a biologia populacional de G. luteus em um estuário da Amazônia Oriental. Para tanto, realizaram-se coletas de exemplares da espécie no Furo Grande, no período de outubro de 2012 a outubro de 2013, mensalmente, com rede de emalhar tipo block-net. Em laboratório, os indivíduos foram aferidos os comprimentos total, padrão e da cabeça e a altura, além de ser registrado o peso úmido. Após incisão ventral e retirada das gônadas, macroscopicamente, definiu-se o estádio gonadal das fêmeas e dos machos. Foram capturados 460 indivíduos cujos tamanhos e pesos variaram entre 4,50 e 21,40 cm e 1,36 e 148,26 g. As frequências relativas das fêmeas e dos machos foram diferentes do esperado de 1:1 (x2: 8,90; p<0,01), diferindo significativamente por sexo e classe de tamanho (p<0,01). As médias de tamanho (CT) apresentaram diferenças significativas em relação ao sexo (F=22,71; p<0,01), mês (F=35,80; p<0,01), período sazonal (F=6,03; p<0,01), estádio gonadal (F=29,77; p<0,01) e estádio gonadal por período sazonal (F=2,37; p<0,05). O peso úmido não diferiu estatisticamente por estádio gonadal, período sazonal e sexo. O diagrama de ordenação demonstrou que a turbidez da água foi a variável que respondeu pela maior variabilidade dos dados (total de 97%). Os espécimes capturados neste estudo são pequenos em tamanho e peso e reprodutivamente imaturos, com maior ocorrência de fêmeas e em maior número no período seco.

Genyatremus luteus is specie of commercial importance in the Pará state. In this study, the population biology of G. luteus was investigated in an estuary of the Eastern Amazon, the collections occurred from October 2012 to October 2013, each month, in the tidal channel (Furo grande), with block net. In the laboratory the individuals were gauged the lengths: total, standard, head and height, in addition to weight being recorded. After ventral incision and gonads removal, the gonadal stage was defined for females and males macroscopically. 460 individuals were captured whose sizes and weights ranged from 4.50 to 21.40 cm and 1.36 and 148.26 g. The relative frequencies of females and males were different than expected from 1: 1 (x2: 8.90, p <0.01), differing significantly by sex and size class (p <0.01). The mean size (CT) presented differences significant in relation to sex (F = 22.71, p <0.01), month (F = 35.80, p <0.01) (P <0.01), gonadal stage (F = 29.77, p <0.01) and gonadal stage by seasonal period (F = 2.37, p <0.05). The wet weight did not differ statistically by gonadal stage, seasonal period and sex. The ordering diagram showed that the turbidity was the variable that responded by the greater variability in the data (total of 97%). The specimens captured in this study are small in size and weight and reproductively immature, with higher occurrence of females, in greater numbers in the dry period.

Experimental study on the efficiency of different types of traps and baits for harvesting Macrobrachium amazonicum (Heller, 1862) / Estudo experimental da eficiências de diferentes tipologias de artes e iscas para a captura de Macrobrachium amazonicum (Heller, 1862)

Macrobrachium amazonicum is a freshwater prawn endemic to South America with wide distribution in Brazilian Amazon rivers. In estuary and freshwater streams of the Pará State, they are captured with different types of traps locally know matapi. This study evaluated the efficiency of traps of different sizes (large, medium and small) and baits (babassu coconut and fish) for sampling this shrimp. Samplings were conducted with 24 traps with different treatments (trap size and bait). We captured 909 specimens. Higher mean catches were observed in traps baited with babassu coconut. Interactions between babassu coconut bait and medium matapi (BM-M), and fish bait and large matapi (FISH-L) were significant. Carapace length (CL) varied significantly between sites (F = 12.74, p 0.01). The total maximum length was13.65 cm. Medium traps baited with babassu coconut were the most successful in the tested combinations, however, there was a clear correlation between size trap and size of shrimp, for both body weight and carapace length.(AU)

Macrobrachium amazonicum é uma espécie de camarão endêmico da América do Sul e está amplamente distribuída nos rios da bacia amazônica brasileira. Nos estuários e cursos de água do estado do Pará são capturados com uso de armadilhas tradicionais conhecidos como matapis. O presente estudo incidiu sobre as técnicas utilizadas pelos pescadores locais, no estado do Pará, além de avaliar a eficácia de diferentes tipos de armadilhas (com tamanhos grande, médio e pequeno) e iscas (de peixe ou farelo de babaçu). As amostras foram obtidas por 24 armadilhas sob diferentes tratamentos (tamanho da arte e isca). Foram capturados 909 indivíduos. As capturas médias nos locais foram maiores nas armadilhas com farelo de babaçu. As interações entre isca babaçu e matapis de tamanho médio (BM- M), e isca de peixe e grandes matapis (FISH- L) foram significativas. O comprimento da carapaça (CL) variou significativamente entre os locais (F = 12,74, p 0,01). O comprimento máximo total registrado foi de 13,65 cm. As armadilhas de médio porte com isca de babaçu foram os mais bem sucedidos nas combinações testadas, no entanto, houve uma clara relação entre o tamanho da armadilha e o tamanho do camarão capturado, tanto em termos de peso corporal e comprimento da carapaça(AU)

Composition of shrimp populations (Crustacea: Decapoda) in non-vegetated areas of two river islands in a Brazilian Amazon estuary

This study investigates the shrimp found in non-vegetated areas of an estuary of the Amazon River. We ascertained the input of juveniles, species' biometrics and the influence of environmental factors on the abundance of species. The samples were collected monthly, from August 2006 to July 2007, in two places in the estuary, each next to an island. For collecting, we used a manual trawl to perform three hauls per month, totaling 36 samples per site. The abundance of shrimps was estimated as a function of the density of specimens per unit area. We used the Spearman's correlation to test the hypothesis that there is significant correlation between the average of the environmental variables measured and variations in shrimp density. The Kruskal-Wallis and the Mann-Whitney tests showed that there were significant differences in environment factors (temperature and salinity) among the months and sites. We obtained 6,091 shrimps, from which 5,231 (85.88%) were caught off the Arapiranga Island and 860 (14.12%) off the Mosqueiro Island, Palaemonidae and Penaeidae were the only families recorded. Five species were collected: Macrobrachium amazonicum (Heller, 1862), Macrobrachium surinamicum Holthuis, 1948, Macrobrachium carcinus (Linnaeus, 1758), Macrobrachium rosenbergii (De Man, 1879), and Farfantepenaeus subtilis (Pérez-Farfante, 1967). The latter (pink shrimp) was found for the first time in oligohaline environments (0-8). Macrobrachium amazonicum was the most abundant species. The recruitment of M. amazonicum juveniles was continuous throughout the year. The population of M. surinamicum was composed by juveniles and adults and that of F. subtilis exclusively by juveniles. The environmental factors analyzed were variable throughout the year and seem to explain the patterns of shrimp species occurrence in the region, the variation in their abundance and juvenile recruitment.

Composition of shrimp populations (Crustacea: Decapoda) in non-vegetated areas of two river islands in a Brazilian Amazon estuary

This study investigates the shrimp found in non-vegetated areas of an estuary of the Amazon River. We ascertained the input of juveniles, species' biometrics and the influence of environmental factors on the abundance of species. The samples were collected monthly, from August 2006 to July 2007, in two places in the estuary, each next to an island. For collecting, we used a manual trawl to perform three hauls per month, totaling 36 samples per site. The abundance of shrimps was estimated as a function of the density of specimens per unit area. We used the Spearman's correlation to test the hypothesis that there is significant correlation between the average of the environmental variables measured and variations in shrimp density. The Kruskal-Wallis and the Mann-Whitney tests showed that there were significant differences in environment factors (temperature and salinity) among the months and sites. We obtained 6,091 shrimps, from which 5,231 (85.88%) were caught off the Arapiranga Island and 860 (14.12%) off the Mosqueiro Island, Palaemonidae and Penaeidae were the only families recorded. Five species were collected: Macrobrachium amazonicum (Heller, 1862), Macrobrachium surinamicum Holthuis, 1948, Macrobrachium carcinus (Linnaeus, 1758), Macrobrachium rosenbergii (De Man, 1879), and Farfantepenaeus subtilis (Pérez-Farfante, 1967). The latter (pink shrimp) was found for the first time in oligohaline environments (0-8). Macrobrachium amazonicum was the most abundant species. The recruitment of M. amazonicum juveniles was continuous throughout the year. The population of M. surinamicum was composed by juveniles and adults and that of F. subtilis exclusively by juveniles. The environmental factors analyzed were variable throughout the year and seem to explain the patterns of shrimp species occurrence in the region, the variation in their abundance and juvenile recruitment.

Composition of shrimp populations (Crustacea: Decapoda) in non-vegetated areas of two river islands in a Brazilian Amazon estuary

This study investigates the shrimp found in non-vegetated areas of an estuary of the Amazon River. We ascertained the input of juveniles, species' biometrics and the influence of environmental factors on the abundance of species. The samples were collected monthly, from August 2006 to July 2007, in two places in the estuary, each next to an island. For collecting, we used a manual trawl to perform three hauls per month, totaling 36 samples per site. The abundance of shrimps was estimated as a function of the density of specimens per unit area. We used the Spearman's correlation to test the hypothesis that there is significant correlation between the average of the environmental variables measured and variations in shrimp density. The Kruskal-Wallis and the Mann-Whitney tests showed that there were significant differences in environment factors (temperature and salinity) among the months and sites. We obtained 6,091 shrimps, from which 5,231 (85.88%) were caught off the Arapiranga Island and 860 (14.12%) off the Mosqueiro Island, Palaemonidae and Penaeidae were the only families recorded. Five species were collected: Macrobrachium amazonicum (Heller, 1862), Macrobrachium surinamicum Holthuis, 1948, Macrobrachium carcinus (Linnaeus, 1758), Macrobrachium rosenbergii (De Man, 1879), and Farfantepenaeus subtilis (Pérez-Farfante, 1967). The latter (pink shrimp) was found for the first time in oligohaline environments (0-8). Macrobrachium amazonicum was the most abundant species. The recruitment of M. amazonicum juveniles was continuous throughout the year. The population of M. surinamicum was composed by juveniles and adults and that of F. subtilis exclusively by juveniles. The environmental factors analyzed were variable throughout the year and seem to explain the patterns of shrimp species occurrence in the region, the variation in their abundance and juvenile recruitment.

Composition of shrimp populations (Crustacea: Decapoda) in non-vegetated areas of two river islands in a Brazilian Amazon estuary

This study investigates the shrimp found in non-vegetated areas of an estuary of the Amazon River. We ascertained the input of juveniles, species' biometrics and the influence of environmental factors on the abundance of species. The samples were collected monthly, from August 2006 to July 2007, in two places in the estuary, each next to an island. For collecting, we used a manual trawl to perform three hauls per month, totaling 36 samples per site. The abundance of shrimps was estimated as a function of the density of specimens per unit area. We used the Spearman's correlation to test the hypothesis that there is significant correlation between the average of the environmental variables measured and variations in shrimp density. The Kruskal-Wallis and the Mann-Whitney tests showed that there were significant differences in environment factors (temperature and salinity) among the months and sites. We obtained 6,091 shrimps, from which 5,231 (85.88%) were caught off the Arapiranga Island and 860 (14.12%) off the Mosqueiro Island, Palaemonidae and Penaeidae were the only families recorded. Five species were collected: Macrobrachium amazonicum (Heller, 1862), Macrobrachium surinamicum Holthuis, 1948, Macrobrachium carcinus (Linnaeus, 1758), Macrobrachium rosenbergii (De Man, 1879), and Farfantepenaeus subtilis (Pérez-Farfante, 1967). The latter (pink shrimp) was found for the first time in oligohaline environments (0-8). Macrobrachium amazonicum was the most abundant species. The recruitment of M. amazonicum juveniles was continuous throughout the year. The population of M. surinamicum was composed by juveniles and adults and that of F. subtilis exclusively by juveniles. The environmental factors analyzed were variable throughout the year and seem to explain the patterns of shrimp species occurrence in the region, the variation in their abundance and juvenile recruitment.

Composition of shrimp populations (Crustacea: Decapoda) in non-vegetated areas of two river islands in a Brazilian Amazon estuary

This study investigates the shrimp found in non-vegetated areas of an estuary of the Amazon River. We ascertained the input of juveniles, species' biometrics and the influence of environmental factors on the abundance of species. The samples were collected monthly, from August 2006 to July 2007, in two places in the estuary, each next to an island. For collecting, we used a manual trawl to perform three hauls per month, totaling 36 samples per site. The abundance of shrimps was estimated as a function of the density of specimens per unit area. We used the Spearman's correlation to test the hypothesis that there is significant correlation between the average of the environmental variables measured and variations in shrimp density. The Kruskal-Wallis and the Mann-Whitney tests showed that there were significant differences in environment factors (temperature and salinity) among the months and sites. We obtained 6,091 shrimps, from which 5,231 (85.88%) were caught off the Arapiranga Island and 860 (14.12%) off the Mosqueiro Island, Palaemonidae and Penaeidae were the only families recorded. Five species were collected: Macrobrachium amazonicum (Heller, 1862), Macrobrachium surinamicum Holthuis, 1948, Macrobrachium carcinus (Linnaeus, 1758), Macrobrachium rosenbergii (De Man, 1879), and Farfantepenaeus subtilis (Pérez-Farfante, 1967). The latter (pink shrimp) was found for the first time in oligohaline environments (0-8). Macrobrachium amazonicum was the most abundant species. The recruitment of M. amazonicum juveniles was continuous throughout the year. The population of M. surinamicum was composed by juveniles and adults and that of F. subtilis exclusively by juveniles. The environmental factors analyzed were variable throughout the year and seem to explain the patterns of shrimp species occurrence in the region, the variation in their abundance and juvenile recruitment.