Crescimento e estado de explotação do siri-vermelho Callinectes bocourti A. Milne-Edwards, 1879 em estuários da Amazônia.

Abstract

The objective of this work was to estimate the growth and the state of exploitation of the Callinectes bocourti Red crab in the Bragança, Salinópolis and Vigia estuaries. A total of 1,347 individuals were captured in the period from October 2011 to December 2013, with a 17 mm mesh pull. In the Crustaceans Laboratory (CEPNOR / ICMBio) the sex of the specimens was identified and the following characteristics were measured: Carapace width (CW) and Carapace length (CL) in centimeter, Weight (W) in grams. Data were collected and run in the FISAT II Program. Von Bertalanffy model was used to estimate the growth curve. To obtain the theoretical size with age 0 (t0) was obtained by the Pauly equation. The longevity was determined by the inverted equation of Von Bertalanffy and from the values of L∞ and K it was possible to estimate the performance index (ɸ'). Natural mortality (M) was done using the Pauly method. The total mortality (Z) was established by the Ricker catch curve method. Fishing mortality (F) was obtained by the relation between total and natural mortality (F = Z - M). The rate of exploitation was estimated by the Pauly equation. Males were more frequent than females in Bragança (74.30% and 25.70%), Salinópolis (71.55% and 28.45%) and Vigia (55.28% and 44.72%). The estuarine environments under study present multiple cohorts (7, 4 and 3 cohorts, respectively) during the years studied. The growth parameters obtained for the estuaries were as follows: the maximum length (L∞) = 15.65 cm; the growth constant (K) = 0.77 year-1; performance index (ɸ ') = 2.28; theoretical size with age 0 (t0) = -0.60 and longevity (t max) = 3.89 years. The growth curve obtained for LC of the species was CL = 4.5166 * ln (t) + 8, 705. Natural mortality was higher in Salinópolis (M = 1.90 year -1); lower in Vigia (M = 1.66 year-1) and Bragança had M = 1.79 year-1. Total mortality (Z) was higher in Salinópolis and Bragança (3.10 year-1 and 2.99 year-1, respectively) and lower in Vigia (Z = 2.39 year-1). Fishing mortality was higher in Salinópolis (F = 1.44 year-1) and Bragança (F = 1.20 year-1) and lower in Vigia (F = 0.49 year-1). The state of exploitation was higher in Bragança and Salinópolis (0.40 and 0.47, respectively) and Vigia was lower (E = 0.20). In Vigia was characterized as growth area for the species. The L∞ and K of C. bocourti in estuaries in studies was considered moderately fast. The mortality for C. bocourti was low due to a low rate of fishing mortality, especially in Vigia. The state of exploitation shows that the species is underexploited in the Northeast of Paraense, and a good management can be elaborated for the exploitation of the species in the region.