尼罗罗非鱼（Oreochromis niloticus）不同月龄性状的主成分与判别分析

摘要

采用主成分与判别分析的方法，研究尼罗罗非鱼形态性状的增长规律，并判定其最佳生长季节体格与月龄的关系。选择2—5月龄尼罗罗非鱼各100尾，测量体长、头长、躯干长、体高、尾柄长、尾柄高、体宽和体重共8个性状，并对其进行主成分与判别分析。主成分分析结果表明：尼罗罗非鱼各月龄的体型特征参数间均有不同程度的正相关（P〈0．05），体重与体长、体高的相关性最显著；不同月龄尼罗罗非鱼性状的主成分有所不同，主成分1：2—5月龄均相同为增重因子；主成分2：2—4月龄均为尾柄因子，而5月龄是躯干因子；主成分3：2月龄是头部因子，3—4月龄是躯干因子，5月龄是尾柄因子。通过建立判别式来判断错过最佳生长季节尼罗罗非鱼的体格与大小相符的月龄，判别结果表明．总的判别准确率为99．25％．其中2—4月龄斥．罗罗非鱼的判别准确率为100％。%In order to research the growth of morphological traits of Nile tilapia （Oreochromis niloticus） and judge the age matching with the size of Nile tilapia missing the best growing season, data were collected from 100 Nile tilapia at different ages individually. The body length, head length, trunk length, body depth, caudal peduncle length, caudal pedun- cle depth, body width and body weight were measured. The physical characteristics were analyzed by principal component and discriminant analysis. The results showed that the characteristics parameter of traits of Nile tilapia at different ages had notable correlation （P〈0.05）, especially the relationship between body weight and body length and body depth. The prin- cipal components of Nile tilapia at different ages were different. The first principal component is body weight factor at 2--5 months. The second principal component was caudal peduncle factor at 2--4 months, but that was trunk factor at 5-month-old. The third principal component was head factor at 2-month-old, was trunk factor at 3--4 months, was caudal peduncle factor at 5-month-old. The month age closely related to the size of Nile tilapia which had missed the best growing period was deduced by established diseriminant functions, the overall discriminant accuracy was 99.25%, which was 100% 2--4 months.