應用形態測定學判別台灣沿近海產善泳蟳 (Charybdis natator)資源之系群結構

Morphometric Study on stock discrimination of the swimming crabs,Charybdis natator in the Waters Surrounding Taiwan

李明政(Ming-cheng Li)

指導教授 ： 葉顯椏

國立臺灣大學/理學院/海洋研究所/碩士(2005年)

https://doi.org/10.6342/NTU.2005.02070

摘要

本研究之目的，係以形態學方法，研析台灣週遭海域產善泳蟳(Charybdis natator)資源之系群結構情形，俾供該等資源進行評估管理時之重要參考依據。本研究所依據之善泳蟳樣本，係於2002年3月至2002年11月間，按時採自澎湖近海及台灣週遭海域拖網作業漁船之善泳蟳漁獲。自四個不同海區(台灣北部海域、台灣中部海域、台灣南部海域及澎湖近海)中，總計採得20個獨立樣本，共555隻(雄331隻及雌224隻)善泳蟳。本研究所選取善泳蟳之外部形質計有：47個量測形質及體重等48個特徵形質，以為獨立樣本形態特徵之依據。

獨立樣本間比較形態學之進行步驟如下：(一) 比較海域別雄性善泳蟳外部形態差異情形；(二) 比較海域別雌性善泳蟳外部形態差異情形；(三) 比較雌雄間形態差異情形。經以主成分分析、典型區別分析及聚類分析等形態學方法，研析結果顯示：(1)雄性善泳蟳11個獨立樣本之典型區別分析與聚類分析結果皆顯示：台灣沿近海產善泳蟳可分為澎湖近海群及台灣沿岸群 (包括北部海域、中部海域及南部海域)等兩群。(2)雌性善泳蟳9個獨立樣本之典型區別分析與聚類分析結果亦皆顯示台灣沿近海產善泳蟳可分為澎湖近海群及台灣沿岸群 (包括北部海域、中部海域及南部海域)等兩群。(3)雌與雄善泳蟳20個獨立樣本之典型區別分析與聚類分析結果顯示台灣沿近海產善泳蟳可分為雄性樣本群及雌性樣本群等兩群。

將上述判別結果所得之兩群，分別進行雌雄間個別形質與頭胸甲寬在雌雄間之相對成長比較。個別系群研析結果，皆顯示雌雄間在頭胸甲高、第五腹節寬第六腹節寬等形質，有顯著差異。本結果顯示：善泳蟳雌雄間在腹甲部位之兩型性(dimorphism)特徵極為明顯。

關鍵字

善泳蟳 ； 相對成長 ； 形態測定學 ； 系群判別

並列摘要

Multivariates morphometric analyses are used in this study for the purpose of examining the stock structure of the swimming crab ( Charybdis natator ) in the waters surrounding Northern and Western Taiwan. A total of 555 crabs, which belong to twenty independent crab samples (two samples from the south of the East China Sea and the rest eighteen samples from the inshore waters of Taiwan Strait) drawn from four main inshore regions nearby Taiwan, were collected from March to November of 2002. Crab body weight in company with other 47 morphometric characters of each specimen were carefully measured and provided for morphometric analyses. Principal components analysis, canonical discriminant analysis and cluster analysis were three major methods to be used in this study for among-independent-samples and between-sex comparisons.

Both canonical discriminant analysis and cluster analysis gave the same results that the swimming crab (male and female alike) resource in the inshore region of Taiwan can be grouped as the group of waters surrounding Peng-Hu islands and the group of inshore regions nearby Western Taiwan. Further, between-sex comparison on the relative growth of morphormetric characters versus carapace width indicates that the sexual dimorphism, particularly in the abdomen segment of the crab, appears very significant in this species of crab.

並列關鍵字

relative growth ； Multivariates morphometric analyses ； stock structure ； Charybdis natator

參考文獻

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