Age and growth of ticto barb Puntius ticto (Hamilton 1822) in the river Old Brahmaputra, Bangladesh

Abstract

The age and growth of ticto barb, Puntius ticto (Hamilton 1822) belonging to the
family cyprinidae was studied extensively to gain a knowledge on growth rates and to determine
the success and degree of establishment as well as to forecast the fish’s impact on native fauna. A
total of 1061 individuals were collected from the Old Brahmaputra river from January to
December 2012. To calculate the age and growth of this population, length frequency analysis
was employed. Length-frequency distribution of each sample was decomposed into its component
size groups by using Bhattacharya method and the samples over the study period did not obtain
the progress of any cohort. Age and growth pattern of P. ticto, therefore, was established by
direct fit of length frequency data both to standard and modified von Bertalanffy growth models
with ELEFAN I procedure. The Powell-Wetherall plot yielded an initial asymptotic standard
length for male and female which were 69.30 and 69.91 mm, and Z/K values were 3.108 and
2.192 respectively. Based on direct fitting of growth equation by ELEFAN I method, the
asymptotic standard length of male was 69.93 mm and growth coefficient was 0.90 per year, and
they were 69.93 mm and 1.10 per year for female. The analysis showed no growth oscillation in
both male and female. The relationships of the pooled data of standard length and body weight
for male was BW = 0.00005SL2.96 and for female BW = 0.00006SL2.87. The von Bertalanffy
growth curves were fitted to weight and age data. The asymptotic body weight for male was
14.45 g, growth coefficient 0.90 per year and age at zero body weight -0.006 years. The
asymptotic body weight for female was 11.85 g, growth coefficient 1.12 per year and age at zero
body weight -0.017 years, respectively. The present findings of age and growth will be used as
input data for fisheries management of this valuable species in the Old Brahmaputra river and
adjacent aquatic ecosystems in Bangladesh.