Abstract

PENHA, J. M. F.; MATEUS, L. A. F.  and  BARBIERI, G.. Age and growth of the Duckbill Catfish (Sorubim cf. lima) in the Pantanal. Braz. J. Biol. [online]. 2004, vol.64, n.1, pp. 125-134. ISSN 1519-6984.  http://dx.doi.org/10.1590/S1519-69842004000100014.

The Duckbill Catfish, Sorubim lima, is a predator of large South American rivers. The age and growth of S. lima were studied based on the pectoral fin-spines of samples collected from the Cuiabá River, Pantanal. The samples were taken from commercial and experimental hook-and-line fishing. An analysis of the marginal increment suggests that the growth rings are formed once a year during the dry season, from July to September (ANOVA type I: F = 4.183; g.l. = 3 and 104; p = 0.008). The estimate of the parameters that describe von Bertalanffy's growth curve by nonlinear regression of the observed lengths in the age were: L_¥ = 56.0 cm (fork length); k = 0.245 year^-1; t_o = -2.605 years. The animals were estimated to have a life span of 9.6 years. The findings indicate that the fork length is a good predictor of the age of individuals of this fish species.

Keywords : Duckbill Catfish; age; growth; fin spine; Sorubim lima; Pantanal.