Precision of age estimates from different ageing structures in selected freshwater teleosts

The present study was undertaken with a view to compare the precision of age readings obtained from different ageing structures of some important freshwater teleosts viz., Hypophthalmichthys molitrix, Mastacembelus armatus and Ompok pabda. Standard procedures were followed to study the ageing structures. Based on the highest percent agreement and lowest average percentage of error and coefficient of variation values, precise age estimates were exhibited by opercular bones in H. molitrix and vertebrae in the remaining two fish, M. armatus and O. pabda. When precise age estimates were compared among the age estimates of other ageing structures, highest percent agreement and lowest average percent error and coefficient of variation values were exhibited by vertebrae (versus opercular bones) in H. molitrix and opercular bones (versus vertebrae) in both M. armatus and O. pabda. When mean age estimates from different ageing structures were compared, vertebrae and opercular bones exhibited comparable values in H. molitrix. In M. armatus, mean values of precise age estimates from vertebrae were significantly different from the values of other ageing structures. However, in O. pabda, vertebrae as well as opercular bones showed insignificantly different age readings.