岗更湖鲫的生长和生活史对策研究

Studies on Growth and Life-history Strategy of Crucian Carp in Ganggeng Lake

2008年5～9月于岗更湖取得803尾鲫标本，研究了其生长及生活史类型。用鳞片鉴定年龄，鳞径（R）和体长（L）的关系为L=3．667R-1．737；用特殊von Bertalanffy生长方程、一般von Bertalanffy生长方程、Gompertz生长方程和灰色动态生长模型共4种生长模型拟合了岗更湖鲫的生长，根据各模型拟合残差平方和的大小判断，特殊von Bertalanffy生长方程拟合效果最好；根据r－选择和k－选择的典型特征及7个生态学参数值，判断出岗更湖鲫偏向r－选择，应用平衡产量模式计算改变瞬时捕捞死亡率（F）和渔业补充年龄（tc）对应的产量变化，同样证实岗更湖鲫偏向r-选择。作为渔业管理对策，岗更湖鲫的捕捞年龄应在3龄以上，捕捞强度不应超过2．0。

The growth and life-history strategy of crucian carp were studied based on 803 specimens taken from Ganggeng Lake from May to September, 2008. The scales were used for age determining and growth back-calculating. The relationship between body length （L, cm） and scale radius （R, era） can be expressed as L = 3. 667R - 1. 737. Specialized von Bertalanffy growth formula, generalized von Bertalanffy growth formula, Gompertz growth formula and grey dynamic growth model were used for fitting the length and weight growth of Crucian carp. The sum of residual squares was compared with one another and the results show that Specialized von Bertalanffy growth formula is the most precise model to fit the growth. According to the typical characteristic of r and K selection and the given values of seven ecological parameters, it is concluded that the life-history strategy of Crucian carp tends to be r-selected. Meanwhile, yield per recruit model is applied to calculate the fish yield. And analysis of yield curves also demonstrates that the life-history strategy has a tendency towards r-selection. As a strategy of fishery management, the minimum harvesting age is suggested to be 3 year old, fishing intensity should not be more than 2.0.