Reproductive biology of the migratory freshwater fish Salminus brasiliensis (Cuvier, 1816) in the Cuiabá River basin,Brazil |
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| Authors: | E Barzotto L Mateus |
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| Affiliation: | Postgraduate Program in Ecology and Biodiversity Conservation, Institute of Bioscience and Laboratory of Ecology and Management of Fishery Resources, Federal University of Mato Grosso, Bairro Boa Esperan?a, Cuiabá, MT, Brazil |
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| Abstract: | This study provides information on the reproductive biology of the dorado Salminus brasiliensis from the Cuiabá River basin, through determinating life history trajectories (length at first maturity, fecundity and spawning type) and the reproductive period, thus establishing the relationships between biotic factors and rainfall and river levels that might act as potential triggers for maturation and spawning. Salminus brasiliensis is a migratory species of great commercial and ecological importance. Individuals were collected monthly from August 2013 to July 2014 in the Cuiabá River. Analyses were performed based on biometric data and the gonads. Females attained greater lengths than males in the Cuiabá River basin, and with a significant difference in the sex ratio in favor of females. Peak reproductive activity occurred in November and December and was related to rainfall. Reproduction was seasonal, with spawning and reproductive potential correlating positively with the length and mass of the gonads of mature females. Average length at first maturity for females was estimated at 55 cm. A regular (annual) monitoring programme of essential biological variables to support a trend analysis over years (not just a snapshot study, as this one) is strongly recommended in order to give advice for the proper fishing policies in the region, as without regular basic data on the population dynamics, management is not possible. |
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