珠江流域3个野生大眼鳜群体的形态差异

采用传统形态学和框架分析法,对广西三江段的右江(ZY)、左江(YJ)及红水河(HSH)野生大眼鳜(Siniperca kneri)群体的110个个体形态比例性状进行比较研究。利用SPSS17.0软件对33项(11项传统形态与21项框架形态)形态学可量性状比例数据进行单因素方差分析、主成分分析(Principal Component Analysis,PCA)和聚类分析(Cluster Analysis,CA)。依据可量性状的LSD单因素比较分析结果,3个种群大眼鳜的显著差别主要体现在头部及尾部性状特征;其中,红水河群体分别与右江群体、左江群体在头部HW/BL、ED/BL、U(10-11)]及尾部CPL/BL、N(5-6)]存在显著差异,而右江群体与左江群体之间不存在显著差异。在比较大眼鳜群体形态差异上,框架结构性状C(1-11)、E(2-11)、F(2-10)、G(3-4)、I(3-9)、M(4-10)、K(4-9)、J(4-5)、T(9-10)、O(5-8)、N(5-6)、P(5-7)、R(7-8)、S(8-9),即大眼鳜的头部及躯干部框架性状可以作为解释其差异的主要成分,而传统形态外形大小则作为解释其差异的次要成分。LSD单因素方差分析结果和聚类分析结果均一致表明:左江群体与右江群体首先聚为一支,再与红水河群体聚为一支。以上结果显示:大眼鳜3个群体存在形态差异,且与其地理分布密切相关。本研究从形态特征上为珠江流域广西江段大眼鳜群体的划分提供科学数据,为大眼鳜优良品种的培育和种质资源保护提供理论依据。

Morphological differentiation among three wild populations of Siniperca kneri in Pearl River

The Pearl River Basin, as the largest river of southern China, comprises the Xijiang River, North River, East River and Pearl River Delta. With abundant water and fish resources, Xijiang River, which comprises the Nanpan River, Hongshui River, Qianjiang River, Youjiang River and Zuojiang River, has a wide basin that represents 77.8% of the Pearl River Basin. The big-eye mandarin fish (Siniperca knerii Garman, 1912), belonging to the Perciformes, Serrani-dae,Siniperca, is a special and precious freshwater fish distributed only in China, especially in the Pearl River.S. kneri, which is a carnivorous freshwater fish with a favorable taste and abundant nutrients, has become one of the most im-portant commercial freshwater fish in China, and has the potential to be a candidate aquaculture species because of its significant economic and ecological value. However, some negative factors, such as the constant severe water pollution, the building of water conservation engineering works, overfishing, and electrifying and bombing of fishes, have led to its miniaturization, low annualized phenomenon and rapid reduction of its wild population. Morphological differentia-tion among three wild populations (YJ: Youjiang River, ZJ: Zuojiang, HSH: Hong Shui He River) ofS. kneri in the Pearl River was studied based on traditional morphology and a truss network of distance measurements. We aimed to learn more about the germplasm resource ofS. kneriby determining the differences among the three populations and to provide reliable scientific evidence to underpin the protection and use of germplasm resources ofS. kneri. Three multi-variate analysis methods were used (One-Way ANOVA, principal component analysis and cluster analysis) for 33 morphometric proportional parameters, using SPSS17.0 software. Based on the LSD results of one-way ANOVA for the measurable characters, there were significant differences between threeS. kneri populations, mainly in the head and tail traits. Specifically, there was a significant difference in the head traits HW/BL, ED/BL, U (10–11)] and tail traits CPL/BL, N (5–6)] between the HSH population and ZJ population, and between the HSH population and YJ popula-tion, respectively; however, there was no significant difference between the ZJ population and YJ population. For the morphological differences among populations, the contribution of the truss network of distance measurements C(1–11), E(2–11), F(2–10), G(3–4), I(3–9), M(4–10), K(4–9), J(4–5), T(9–10), O(5–8), N(5–6), P(5–7), R(7–8) and S(8–9) indi-cated that the truss network of the head and trunk ofS. kneri was the principal component, and the contribution of tradi-tional characters was the second. Cluster analyses suggested consistently that the ZJ and YJ populations clustered first and then clustered with the HSH population, whether based on the traditional morphology or the truss network. All of the above indicated that morphological differentiation nexisted among the three populations and was closely associated their geographical distribution. The results, representing basic knowledge ofSiniperca kneriin Pearl River, provide reliable sci-entific evidence for the protection and use of germplasm resources and for artificial selection breeding ofS. kneri.