Lethal Effect of Nitrite to Juvenile Metapenaeus Ensis

Abstract

This study used morphometric traits as potential criteria for the selectionof future Penaeus semisulcatus broodstocks.Prawns were collected from Kao-hsiung and Tungkang waters in southern Taiwan.Twenty-one morphometrictraits including tail weight were measured from each prawn.The results showed significantly higher mean values of tail weight andmost other morphometric traits in female prawns of this species from Tung-kang.There were no significant differences in all morphometric traits inmales from both locations.Stepwise multiple regression analysis showed thata large portion of variance in tail weight can be explained by a single variable,that is,by partial total length(PTL)in female prawn and by secondabdominal segment depth(SAD)in male.These variables can give a moreaccurate estimate of tail weight and can be used as a basis for broodstock selection in prawn culture. 本研究利用外部形質之測量值作爲熊蝦種蝦選種之參考。熊蝦種蝦之樣品分別採自東港及高雄海域，每尾共測量包括尾重(TW)在內之二十一個外部形質。結果東港所採之雌性能蝦，其平均尾重及絕大多數外部形質均顯著高於高雄所採者；至於兩地之雄性熊蝦，在外部形質上則無顯著差異。應用多變値複廻歸分析，顯示絕大部份尾重的變異，在雌性熊蝦可由其眼窩後端至尾柄外肢之長度(PTL)加以解釋；雄性者則可用第二及第三腹節間的高度(SAD)來說明；亦卽藉這兩個形質可以精確地評估尾重，並進而可作爲熊蝦種蝦選種之參考。