Microbiological condition of the catfish Sciades herzbergii from Bacanga Lagoon, northeastern Brazil / Qualidade microbiológica do bagre Sciades herzbergii capturado na Laguna do Bacanga, nordeste do Brasil

Fishing in Bacanga Lagoon supplements the income or even guarantees the survival of several families that live in this river basin on Maranhão Island (São Luís), which is densely populated and shows signs of water pollution. The present study aimed to assess the quality of recently captured catfish Sciades herzbergii, through microbiological analyses of muscles. In general, the samples of Bacanga Lagoon showed higher coliform values than those observed in fish collected in the control area (Pau Deitado, Paço do Lumiar, state of Maranhão). Samples collected in January showed a high content of total coliforms and coliforms at 45oC, which suggests a relationship between microbial contamination and the rainy season. Escherichia coli was the most abundant bacteria species in the samples from Bacanga Lagoon. The results showed poor sanitary conditions of the Bacanga Lagoon and demonstrated fecal contamination of the fish captured due to the high amount of untreated efluents discharged in the lagoon.

A pesca na laguna do Bacanga é uma atividade que garante o sustento e complementação de renda para diversas famílias que habitam nessa bacia hidrográfica da Ilha do Maranhão (São Luís) densamente ocupada e com sinais de poluição de suas águas. O trabalho objetivou avaliar a qualidade do bagre Sciades herzbergii através de análises microbiológicas do músculo de peixes recém-capturados. No geral, as amostras do Bacanga apresentaram valores de coliformes significativamente maiores que os observados nos peixes coletados na área controle (Pau Deitado, Paço do Lumiar, MA). Amostras coletadas nos meses de janeiro apresentaram elevada quantidade de coliformes totais e coliformes a 45oC sugerindo relação da contaminação microbiana com o período de chuvas, sendo que Escherichia coli foi a espécie mais abundante nas amostras do Bacanga. Os resultados indicaram as péssimas condições sanitárias da laguna do Bacanga e demostraram a contaminação de origem fecal nos peixes capturados em função do elevado volume de efluentes lançados sem tratamento na laguna.

Microbiological condition of the catfish Sciades herzbergii from Bacanga Lagoon, northeastern Brazil / Qualidade microbiológica do bagre Sciades herzbergii capturado na Laguna do Bacanga, nordeste do Brasil

Fishing in Bacanga Lagoon supplements the income or even guarantees the survival of several families that live in this river basin on Maranhão Island (São Luís), which is densely populated and shows signs of water pollution. The present study aimed to assess the quality of recently captured catfish Sciades herzbergii, through microbiological analyses of muscles. In general, the samples of Bacanga Lagoon showed higher coliform values than those observed in fish collected in the control area (Pau Deitado, Paço do Lumiar, state of Maranhão). Samples collected in January showed a high content of total coliforms and coliforms at 45oC, which suggests a relationship between microbial contamination and the rainy season. Escherichia coli was the most abundant bacteria species in the samples from Bacanga Lagoon. The results showed poor sanitary conditions of the Bacanga Lagoon and demonstrated fecal contamination of the fish captured due to the high amount of untreated efluents discharged in the lagoon.(AU)

A pesca na laguna do Bacanga é uma atividade que garante o sustento e complementação de renda para diversas famílias que habitam nessa bacia hidrográfica da Ilha do Maranhão (São Luís) densamente ocupada e com sinais de poluição de suas águas. O trabalho objetivou avaliar a qualidade do bagre Sciades herzbergii através de análises microbiológicas do músculo de peixes recém-capturados. No geral, as amostras do Bacanga apresentaram valores de coliformes significativamente maiores que os observados nos peixes coletados na área controle (Pau Deitado, Paço do Lumiar, MA). Amostras coletadas nos meses de janeiro apresentaram elevada quantidade de coliformes totais e coliformes a 45oC sugerindo relação da contaminação microbiana com o período de chuvas, sendo que Escherichia coli foi a espécie mais abundante nas amostras do Bacanga. Os resultados indicaram as péssimas condições sanitárias da laguna do Bacanga e demostraram a contaminação de origem fecal nos peixes capturados em função do elevado volume de efluentes lançados sem tratamento na laguna.(AU)

Reproductive biology of Sciades herzbergii (Siluriformes: Ariidae) in a tropical estuary in Brazil

The present study investigated the reproductive biology of Sciades herzbergii in the Paraíba do Norte River Estuary, Brazil. We aimed to characterize the reproduction of the species with respect to sex ratio, spawning season, condition factor and length at first maturity. Specimens were captured between August 2009 and July 2010 in a stretch of the main channel of the estuary. In the laboratory, they were measured, weighed and macroscopically classified with regard to sex and gonad development stage, and their gonads were weighted. The monthly distribution of the sexes and their respective stages of maturation were determined. The gonadosomatic index (GSI), condition factor (K) and the length at first maturity were calculated for males and females. The sex ratio was determined monthly and throughout the entire study period and the chi-square test was used to evaluate if the sex ratio differed from 1:1. The Pearson's correlation test was used to determine the correlation between GSI and K values. A total of 260 individuals were captured. It was impossible to determine the sex of 32 individuals, possibly due to their young age. The sex ratio did not differ throughout the overall study period, but significant differences were found in December and May, with a predominance of females, and in March, when males predominated. Spawning activities were concentrated between December and March, as determined by the greater incidence of mature females and higher GSI values. The spawning of the S. herzbergii population is characterized as staggered due to its long duration. For females, K values were not significantly correlated with the GSI, but the decrease in K values in the spawning period indicates that energy is being spent in reproduction. With regard to males, the distribution of developmental stages did not follow the same clear pattern as that seen with females. However, the GSI indicated a greater investment in gonads in October, with a decrease up to July (end of the data acquisition period). For males, K values exhibited a positive correlation with GSI, with a gradual decrease beginning in February up to July, indicating energy that energy was being consumed, which was certainly related to the mouth brooding of eggs and neonates. Mean length at first maturity was 212 mm for females and 240 mm for males. Sciades herzbergii completes its lifecycle in the estuary and exhibits post-spawning parental care. This species is abundant in the estuary studied and information on the reproductive biology of this resident is necessary to the management of the estuarine environment.

Reproductive biology of Sciades herzbergii (Siluriformes: Ariidae) in a tropical estuary in Brazil

The present study investigated the reproductive biology of Sciades herzbergii in the Paraíba do Norte River Estuary, Brazil. We aimed to characterize the reproduction of the species with respect to sex ratio, spawning season, condition factor and length at first maturity. Specimens were captured between August 2009 and July 2010 in a stretch of the main channel of the estuary. In the laboratory, they were measured, weighed and macroscopically classified with regard to sex and gonad development stage, and their gonads were weighted. The monthly distribution of the sexes and their respective stages of maturation were determined. The gonadosomatic index (GSI), condition factor (K) and the length at first maturity were calculated for males and females. The sex ratio was determined monthly and throughout the entire study period and the chi-square test was used to evaluate if the sex ratio differed from 1:1. The Pearson's correlation test was used to determine the correlation between GSI and K values. A total of 260 individuals were captured. It was impossible to determine the sex of 32 individuals, possibly due to their young age. The sex ratio did not differ throughout the overall study period, but significant differences were found in December and May, with a predominance of females, and in March, when males predominated. Spawning activities were concentrated between December and March, as determined by the greater incidence of mature females and higher GSI values. The spawning of the S. herzbergii population is characterized as staggered due to its long duration. For females, K values were not significantly correlated with the GSI, but the decrease in K values in the spawning period indicates that energy is being spent in reproduction. With regard to males, the distribution of developmental stages did not follow the same clear pattern as that seen with females. However, the GSI indicated a greater investment in gonads in October, with a decrease up to July (end of the data acquisition period). For males, K values exhibited a positive correlation with GSI, with a gradual decrease beginning in February up to July, indicating energy that energy was being consumed, which was certainly related to the mouth brooding of eggs and neonates. Mean length at first maturity was 212 mm for females and 240 mm for males. Sciades herzbergii completes its lifecycle in the estuary and exhibits post-spawning parental care. This species is abundant in the estuary studied and information on the reproductive biology of this resident is necessary to the management of the estuarine environment.

Reproductive biology of Sciades herzbergii (Siluriformes: Ariidae) in a tropical estuary in Brazil

The present study investigated the reproductive biology of Sciades herzbergii in the Paraíba do Norte River Estuary, Brazil. We aimed to characterize the reproduction of the species with respect to sex ratio, spawning season, condition factor and length at first maturity. Specimens were captured between August 2009 and July 2010 in a stretch of the main channel of the estuary. In the laboratory, they were measured, weighed and macroscopically classified with regard to sex and gonad development stage, and their gonads were weighted. The monthly distribution of the sexes and their respective stages of maturation were determined. The gonadosomatic index (GSI), condition factor (K) and the length at first maturity were calculated for males and females. The sex ratio was determined monthly and throughout the entire study period and the chi-square test was used to evaluate if the sex ratio differed from 1:1. The Pearson's correlation test was used to determine the correlation between GSI and K values. A total of 260 individuals were captured. It was impossible to determine the sex of 32 individuals, possibly due to their young age. The sex ratio did not differ throughout the overall study period, but significant differences were found in December and May, with a predominance of females, and in March, when males predominated. Spawning activities were concentrated between December and March, as determined by the greater incidence of mature females and higher GSI values. The spawning of the S. herzbergii population is characterized as staggered due to its long duration. For females, K values were not significantly correlated with the GSI, but the decrease in K values in the spawning period indicates that energy is being spent in reproduction. With regard to males, the distribution of developmental stages did not follow the same clear pattern as that seen with females. However, the GSI indicated a greater investment in gonads in October, with a decrease up to July (end of the data acquisition period). For males, K values exhibited a positive correlation with GSI, with a gradual decrease beginning in February up to July, indicating energy that energy was being consumed, which was certainly related to the mouth brooding of eggs and neonates. Mean length at first maturity was 212 mm for females and 240 mm for males. Sciades herzbergii completes its lifecycle in the estuary and exhibits post-spawning parental care. This species is abundant in the estuary studied and information on the reproductive biology of this resident is necessary to the management of the estuarine environment.