Abstract: The age structure and growth characteristics of Pseudobagrus truncatus were studied based on 436
 specimens collected from Minjiang River, a Yangtze River’s tributary in November-December 2012 and April-May 2013. The results showed that asteriscus was a good material for determining the age of  P. truncatus. The ages of the specimens ranged from 1-6 years.  The dominated age ranged from 2-3 years, accounting for 81.82% of the total specimens. With the growth of age, the male appeared to grow at a faster rate and there were significant differences in growth patterns between males and females. The relationship between the body length (L) and the body weight (W) appeared as a power function relation, which could be expressed by formula W_♀= 2×10^-4L_2.3822 (n=193, R²=0.904, P<0.01) for females and W_♂ =2×10^-4L_2.4322 (n=225, R²=0.884, P<0.01) for males, respectively. The Gompertz growth function was especially suited to describe the growth patterns. The growth of body length and body weight of the female and male can be described by the Gompertz growth equation as follows: ♀: L_t=785.78e^-1.36e-0.59t, ♂: L_t=926.35e^-1.84e-0.42t; ♀: W_t=438.62 e^-5.61e-0.45t, ♂: W_t=559.64e^-5.49e-0.41t. The inflection points of body length growth were 4.18 years and 4.75 years, and the inflection points of body weight growth were 3.09 years and 2.21 years for the female and male, respectively. Our results indicated that P. truncatus was at younger ages in the study area. In order to sustainably utilize the P. truncatus population, we suggest that only fish larger than 100 mm (10 g) could be harvested.

Key words: EDTA, Pb pollution, emodin, Dianthus superbus, AM fungi