A preliminary study on biology of Glowfish (Gnathodentex aureolineatus) in Yongshu Reef of Nansha area in the South China Sea

Taking Glowfish ( Gnathodentex aureolineatus) collected by handline in Yongshu Reef of Nansha area in the South China Sea in 2013 as samples, we studied the composition and relation of body length with body weight, age composition, sex ratio, gonad maturity composition and feeding intensity of G. aureolineatus. The results show that the ranges of body length of G. aureolineatus were 112～157 mm and 120 ～162 mmin July and September, respectively, no significant difference was found in the body length distribution, average body length and weight ( P 0.05) . The growing parameters ( b value) between body length and body weight in July and September were 2. 814 8 and 2. 629 6, respectively. The age range of 92 otolith identified was 1 ～11 year old. The preponderant class and peak of age were 2 ～4 and 2 years old in July, and 3 ～6 and 6 years old in September. The parameters of the von Bertalanffy growth function were as follows: l =224 mm, K=0. 028, t0 = -27. 282. The gonad maturity of G. aureolineatus were StageⅡ and Ⅲ in July, StageⅠ, Ⅱ and Ⅲ in September; the feeding stages of female and male G. aureolineatus were mainly at Stage 2, 3 and 4 in July and Stage 1, 2 and 3 in September. The repletion index of male G. aureolineatus decreased with increasing body length.