AGE DETERMINATION AND GROWTH OF CHINESE PADDLEFISH PSEPHURUS GLADIUS

Oberservation of compare with the sections of two calcified structrues, iepectoral fin ray and dentary bone from Chinese paddlefish Psephurus gladius were conducted. It reveals that the 3rd to 5th pectoral fin rays are optimal aging structrues for the fish. The age determination of the Chinese paddlefish indicated that 8 immature individuals were 1-3 years of age,58 mature individuals were 6-17 years old. Of these, the majority of 33 males, with the youngest age of 6 years old and the oldest 11, fell between 7-9 age groups; the most of 25 females, with the youngest 7 and the oldest 17, fell between 8-12 age groups. The rate of growth of the Chinese paddlefish appears to be rapid, especially in the first year of life. The Von Bertalanfy Growth Function (VBGF) for growth in length could be written as:for males Lt= 368.5[1-e-0.0901(t+1.66)] for females Lt=436.3[1-e-0.0724(t+2.29)] where Lt= total length in cm, t=age in years. The VBGF for growth in weight could be written as:for males Wt = 148.6[1-e-0.0901(t+1.66)]3.2340 for females Wt= 264.0[1-e-0.0724(t+2.29)]3.2497 where Wt= weight in kg, t = age in year.