北江侧条光唇鱼的个体生殖力

于2007年7月—2009年6月,在北江随机采集侧条光唇鱼(Acrossocheilus parallens)样本358尾,均测量其体长(L)、体质量(W)、净体质量(Wn)和性腺质量(Wo)等生物学指标.从样本中选取卵巢成熟度为IV期的雌性个体73尾,用质量法计数个体绝对生殖力,并对体长相对生殖力(FL)、体质量相对生殖力(FW)进行计算,用5种数学模型及多元回归方程拟合个体生殖力与生物学指标的关系.结果表明:样本由1+~5+龄5个龄组组成;个体绝对生殖力(F)在578~12621粒之间,平均为3303粒,体长相对生殖力在73~908粒/cm之间,平均为282粒/cm,体质量相对生殖力在42~203粒/g之间,平均为87粒/g;个体绝对生殖力及个体体长相对生殖力均与全长、体长、体质量、净体质量、体长体质量复合关系和卵巢质量等呈幂函数相关,两者均与成熟系数和年龄呈指数函数相关,而体质量相对生殖力与各生物学指标相关性不显著.根据生殖力与生物学指标的关系,可以利用体长或体质量预测种群生殖力.根据侧条光唇鱼卵径分布频率特征,初步推测其为分批产卵鱼类.

INDIVIDUAL FECUNDITY OF ACROSSOCHEILUS PARALLENS IN THE BEIJIANG RIVER

There were 358 specimens of Acrossocheilus parallens collected between July 2007 and June 2009 in the Beijiang River. The data for body length （L）, body weight （W）, net body weight （Wn）, ovary weight （Wo） were measured, and the gonadosomatic index and the fullness were calculated. The individual fecundity of 73 female of the total specimens which ovaries at stage Ⅳ and the relationship between the individual fecundity and the biological indexes were studied from July 2007 to June 2009. The relationship between individual absolute fecundity (F) and total length, standard length，body weight，net body weight and ovary weight was described by power equation, and the relationship between F and gonadosomatic indexes, age was regressed best by exponential equation. The individual relative fecundity of body length (FL) was significantly correlated to total length, body length，body weight，net body weight,ovary weight, gonadosomatic indexes and age. Both of F and FL had no obvious relationship with fullness. The FW is not significantly correlated to all the biological indexes. The distribution of egg-diameter in Ⅲ and Ⅳ maturity stage ovary implicated that A.parallens spawns in batches.