Abstract

GONZALEZ, Angel; MENDOZA, Jeremy; AROCHA, Freddy  and  MARQUEZ, Arístide. Crecimiento de la curvinata de río, Plagioscion squamosissimus, en el Orinoco medio. Zootecnia Trop. [online]. 2005, vol.23, n.2, pp.155-170. ISSN 0798-7269.

A study of the growth of Plagioscion squamosissimus was made in the middle Orinoco region in Venezuela, through analyses of the size frequencies and the reading of the growth rings in the otoliths. The samplings were carried out in the main channel and in one of the flooded lagoons near the river, using a net of 10 cm of mesh opening and of known selectivity. No significant differences were found in the size structures of the population, although the fish of the channel reached a larger longitude. Significant differences were not detected in those parameters of the equations of growth in longitude among the fish of the one channel and those of the flood lagoon, and a global equation was considered for the region represented by the function L(t) = 62,6 (1-e^{-0,161 (t+0,37)}). The pattern of growth in weight, for the two areas, presented significant differences and it was represented by the equation W(t) = 1731 (1-e^{-0,127 (t+0,37)} )^2,4008 for fish of the channel and W(t) = 890 (1-e^{-0,120 (t+1,86)} )^2,4008 for the fish of the lagoon. Similarly, the models of growth in longitude, through the reading of the rings in the otoliths, did not present significant differences between the fish of the channel and those of the flooded lagoon. It was considered a model of common growth for the region, represented by the equation L(t) = 69,34 (1-e^{-0,128 (t+0,33)}).

Keywords : Orinoco river; fishing resources; fishing biology; dynamics population; age and growth.