


摘要:運用多變量形態度量學分析方法,對太湖、洪澤湖及南四湖3個湖泊湖鱭(Coilia ectenes)種群的形態變異進行了分析。聚類分析表明,南四湖種群與洪澤湖種群形態最為接近,聚為一支,太湖種群變異最大,成為相對獨立的一支;主成分分析表明,不同湖泊湖鱭種群形態度量參數有重疊,但太湖種群比其他種群形態趨異程度大,已有一定程度的形態分化,分析篩選出前3個主成分的累積貢獻率為52.5%;判別分析采用8個形態變量,分別構建了3個種群的判別函數,其綜合判別準確率為80.6%。
關鍵詞:湖鱭(Coilia ectenes);種群;框架分析;形態差異
中圖分類號:S917文獻標識碼:A 文章編號:0439-8114(2011)21-4445-03
Morphological Variations of Coilia ectenes in Different Lakes
XIANG Wen-dian,XIE Jia-yan,LIN Jia
(School of Biology and Pharmaceutical Engineering, Wuhan Polytechnic University, Wuhan 430023, China)
Abstract: Using the multivariate morphometrics, the morphological variations were investigated among three geographical populations of Coilia ectenes, including the population from Taihu Lake, Hongzehu Lake, and Nansihu Lake. Cluster analysis showed that the morphological characters were similar between the populations of Hongzehu Lake and Nansihu Lake, but quite different of the Taihu Lake population, thus, formed two independent clades. The principal component analysis showed that the three populations shared some morphological characters, but there were distinct differences between the population in Taihu Lake and the other lakes. A toltal of 8 principal components were constructed, the cumulative contribution of this first three principal component was 52.5%. Using the eight variances, three discriminant functions for those three populations were constructed, and the results showed that the prediction accuracy was 80.6%.
Key words: Coilia ectenes; population; frame analysis; morphological variation
形態特征是物種遺傳特性的外在表現,是遺傳多樣性的直接表現形式,長期以來作為物種分類和資源鑒定的主要指標。框架分析方法可通過選取一定數量的解剖學坐標點(Landmark point),將生物體分成若干個功能單元區,從多維空間去度量生物體的外部形態,較精確地反映魚體形態差異,并對眾多的形態變量進行多變量統計分析,篩選出存在顯著差異的形態變量,有效地辨別種間及種內不同地理種群間的形態差異[1-5]。
湖鱭(Coilia ectenes)又稱刀鱭、梅鱭、鳳尾魚等,是我國重要的經濟魚類,隸屬于鯡形目(Clupeiformes)鳀科(Engraulidae)鱭屬,在我國主要分布于長江、黃河、錢塘江以及其他通海河流[6,7]。刀鱭是一種海淡水溯河產卵的洄游性魚類,但有部分親魚可于長江中、下游各通江湖泊定居,形成定居型刀鱭,即湖鱭[6]。鱭魚味道鮮美,營養價值高。然而,由于過度捕撈、環境污染、上游水利設施興建等因素的影響,導致鱭魚的生存環境遭到嚴重的破壞,鱭魚資源急劇下降。……