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Studies on the Population Structure of Swordtip (Loligo edulis) and Mitre (Loligo chinensis) Squids by Using Morphometric Method
|Contributors: ||NTOU:Department of Environmental Biology and Fisheries Science|
Loligo edulis;Loligo chinensis;morphometric method;discriminant analysis
|Issue Date: ||2011-10-20T08:24:57Z
|Publisher: ||台灣水產學會九十四年度論文發表會Pingtung, Taiwan, ROC|
|Abstract: ||為探究台灣東北部、澎湖及新竹海域中，劍尖槍鎖管(Loligo edulis)與台灣鎖管(Loligo chinensis)之形態特性，本研究依種類別及採集地點之不同，以形態學測量法量取749尾鎖管樣本之18項外部形態特徵值，同時利用單變量形態測量學中之指標分析及相對成長速率，以及多變量形態測量學中之判別分析法，來考察劍尖槍鎖管與台灣鎖管間之形態差異，並探討劍尖槍鎖管在台灣東北部海域不同漁場中之形態差異與生態意義。
此外，在東北海域中Area 1、Area 2及Area 3不同地理區域中所取得之劍尖槍鎖管樣本，經逐步判別分析所篩選出的11項形態特徵變量，則可有效的區分出Area 1、Area 2及Area 3之樣本群，其正確判別率達79.08%。其中標準係數以HL、FW及MOW最高，變異較大。而群集分析與典型判別分析結果發現，Area 1與Area 3之樣本形態較為接近，與Area 2形態差異較大。若進一步配合此三地區中鎖管樣本之ML頻度分布則發現，分布在Area 2(潮境漁場)之鎖管，75%是ML介於成熟與未熟之間(70~130mm)的中型鎖管，離岸較近(Area 3)之冷水渦周邊海域屬於育成場及產卵場，體型屬於小型之未成熟體長並有少數大型之成熟體長。形態差異則因其生活史階段改變，會有不同的棲地環境，同時為順應生活史階段上不同的環境狀況及行為，造成其外部形態產生改變。
The aim of this study analyzed the population structure between Swordtip squid (Loligo edulis) and Mitre squid (Loligo chinensis) by using univariate and multivariate morphometric methods in the waters around Taiwan. A total of 18 morphometric characters were measured by the 749 specimens of squid, which were collected from the waters off northeastern Taiwan, Penghu and Hsingtsu regions.
Base on the morphometric characters data, the principle components analysis showed that both of L. edulis and L. chinensis did not exhibit the sexual dimorphism. In the 18 indices, only A3/ML and A4/ML were not significant difference between the L. edulis in the waters off northeastern Taiwan and the L. chinensis in the waters around Penghu, 8 indices (W/ML, HL/ML, A2/ML, A3/ML, A4/ML, FCL/GL, NCL/GL and GW/GL) were not significant difference between the L. edulis in the waters off northeastern Taiwan and the L. chinensis in the waters off Hsingtsu; and only FL/ML and A3/ML were not significant difference between the waters off Penghu and Hsingtsu but they are the same L. chinensis species. The result of relative growth showed the L. chinensis in the waters off Hsingtsu is more different from the L. chinensis in the waters off Penghu than the L. edulis in the waters off northeastern Taiwan.
In total, 13 morphometric characters were selected by using the stepwise discriminant analysis and the discriminant functions had 84.65% correct rate among three region specimens. While, the standard coefficients of the canonical discriminant analysis in the HW, MOW and FW were more different than others. The results of the cluster analysis were the same with canonical discrimanant analysis, the morphometric characters in the waters off Penghu and Hsinghu were more similarity than in the waters off northeastern Taiwan.
In addition, the stepwise discriminant analysis selected 11 morphometric characters of the L. edulis specimens from different fishing ground (Area 1, Area 2 and Area 3) in the waters off northeastern Taiwan. Based on these 11 variables, the discriminant functions could permit 79.08% correct rate among the three area specimens. The results of the cluster analysis and canonical discriminant analysis showed the morphomertic characters of the Area 2 are more different than Area 1 and Area 3. From the frequency of ML in three areas showed that the 75% specimens in Area 2 (ocean front fishing ground) were the mid-size squid (ML between 70 and 130mm), which were the mature and immature squids. However, the squids in Area 3 (upwelling fishing ground) were the small- and large-size, which were the nursing and spawning squids. These results indicated that the squid in order to suit the life cycle in different marine environment and caused the changes of morphometric characters.
|Appears in Collections:||[環境生物與漁業科學學系] 演講及研討會|
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