Dinâmica populacional do tucunaré cichla temensis (humboldt, 1833) do médio Rio Negro, Amazonas, Brasil

Abstract

This study intended to estimate peacock bass Cichla temensis age and populations parameters at the middle Negro river, by the analysis of fish scale growing mark. The samples were caught between October/2011 and September/2012 in the main channel and adjacent lakes, situated at the Barcelos municipality - AM. Were estimated the following biological index and population parameters: Kn (relative factor of condition), IGS (Gonadosomatic Index), L∞ (asymptotic length), k (growing coefficient), A0,95 (longevity), PxC (weight-length relation), L50 (first gonad maturation length), M (natural mortality), Z (total mortality) and F (mortality by fisheries). The growing mark formations period were inspected by the relative marginal increment (IMR), a total of 250 individual. Were possible to identify six growing mark in the scale of C. temensis. The annual variations observed in the Kn suggests that fat accumulation occurs in the dry seasons, once the environmental retractions facilitates to peacock bass the capture of their prey. The IGS results indicated that the period of more reproductive activity occurred in the falling water, its indicates that the fish have an energetically deficit in their organisms related to reproductive activity. Were observed using the IMR analysis that C. temensis forms a ring per year, in the falling period and presenting an allometric growth positive (b>3). The population parameters estimated for C. temensis were: L50 = 31,11 cm; L∞ = 68,05 cm; k = 0,20.year-1; A0,95 = 14 years; M = 0,49.year-1; Z = 0,84.year-1 and F = 0,34.year-1. The growing study realized for C. temensis confirms that the marks in the calcified structures could be used as fish age index and growing rate for tropical regions.