Weight-lenght relationship, grouth and age of cascudo plescostomus albopunctatus Regan, 1908 (Osteichthyes, Loricariidae) from Jaguarí­­ River, São Paulo, Brazil

Abstract

To find out the relationships between total weight/total length, growth rate and age of "cascudo" Plecostomus albopunctatus, it was observed a sample of 1,217 individuaIs: 711 males and 506 females. They were caught in Jaguari River close to Jaguariúna city (22°42'38"S - 047°00'20"W) from June, 1974 to September, 1976. The growth rings were observed in vertebras and they have been formed twice a year: first from June-July to August-September, corresponding to the winter period, and second from December-January to February-March, the summer. Both length and weight growth curves were determined and sexual dimorphism has been observed.