VariaÃÃo espaÃo-temporal das espÃcies da famÃlia Ariidae (Siluriformes) no EstuÃrio do Rio Goiana (PE / PB â Brasil)

AUTOR(ES)
DATA DE PUBLICAÇÃO

2008

RESUMO

The objective of this study was to describe the seasonal variation of the species of the Ariidae Family (biomass and density) in relation to the variables space and time, in the estuary of Goiana River Estuary (NE/Brazil). From December of 2005 to November of 2006, two hundred and sixteen samples were taken representing a total sampled area of 23ha. About 60518 fishes were collected, weighing approximately 600kg. The Family Ariidae species were the most abundant in number 1600 ind.ha-1 (53%) and weight 18813 g.ha-1 (63%). The specie Cathorops spixii was the most abundant in number 1340 ind.ha-1 (44%) and weight 14203 g.ha-1 (48%). The variables number of Ariidae species, density (total mean) and biomass (total mean) showed significant differences for the factors area and season. Moreover, the interaction was significant between these two factors. It suggests that both factors area and season have influenced the distribution of Cathorops spixii, Cathorops agassizi and Sciades herzbergii in the Goiana River Estuary. The highest density (7394 ind.ha-1) occurred in the middle estuary during the early rainy season, while the highest biomass (70292 g.ha-1) values occurred in the upper estuary during the early rainy season. The highest number of species was found in the lower estuary during the late rainy season (Cathorops spixii, Cathorops agassizi, Sciades herzbergii, Sciades proops, Aspistor parkeri and Aspistor luniscustis). Besides, the density of Cathorops spixii differed significantly among areas and seasons, while Cathorops agassizi differed significantly only for the factor season. The biomass differed significantly for the species Cathorops spixii, Cathorops agassizi and Sciades herzbergii among seasons, and Cathorops spixii and Cathorops agassizi among areas. Also, the density and biomass of Cathorops spixii and Cathorops agassizi showed interactions among area and season. The biomass of Sciades herzbergii showed interactions only among season. This indicates that for these species (density and biomass) the seasonal variation influenced their distribution in the different areas of the Goiana River Estuary. This ecosystem showed a great importance for reproduction and recruitment for the species from the Family Ariidae, which required estuarine conditions to complete their life cycle

ASSUNTO(S)

salinity gradient coastal ecosystems gradiente de salinidade atlÃntico ocidental tropical oceanografia tropical occidental atlantic ecologia de bagres movimento de peixes ambientes costeiros catfish ecology fishes movements

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