Population structure and relative growth of freshwater prawn Macrobrachium amazonicum (HELLER, 1862) (Crustacea, Palaemonidae) in two regions of the State of Amapá, Amazon River mouth, Brazil.

• Autor(a) principal: LIMA, J. de F.
• Data de Publicação: 2015
• Outros Autores: SILVA, L. M. A. da
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da EMBRAPA (Repository Open Access to Scientific Information from EMBRAPA - Alice)
• Texto Completo: http://www.alice.cnptia.embrapa.br/alice/handle/doc/1031247
• topic: Crustacean; Growth; Relação morfométrica; Morphometric relationship; Matapi; Crustáceo; Crescimento

Macrobrachium amazonicum is an indigenous prawn vastly distributed in basins of South America, widely exploited by artisanal fisheries in northern and northeastern Brazil and, with great potential for aquaculture. This study aimed at examining the population biology with emphasis on the sex ratio and size frequency distribution. The specimens were analyzed in terms of population structure , sexual ratio, size frequency distribution, recruitment and the relative gr owth was compared by sex and seasons. A number of 5,179 (2,977 females and 2,192 males) were collected monthly using 20 matapis. The sex ratio in both areas was favorable to females with 1:1.36 in Santana Island and 1:1.41 in Mazagão Velho. The monthly distribution of absolute frequency of juveniles , adult males and females varied according to the season in the two areas studied. Adult females were more abundant in the rainier period; while the adult males and females were similarly abundant in the less rain y period. In Santana Island, females were significantly larger than males, while the sizes were similar between sexes in Mazagão Velho. The regression equations applied to the data shown positive allometry in all relations , with r² more than 0.94 in both sex and sites.