海水魚類寄生性橈腳類－魚虱之生活史研究

Abstract

本研究主要對於寄生在海水吳郭魚（Oreochromis mossambica）魚體上的魚虱Caligus sp.生活史的觀查，並將其各期的形態加以詳細描述，其結果如下： 在卵曩中的卵（一隻母蟲中其兩個卵曩內共含有42個卵）->約1.5小時（所有的卵完全孵出）->Nauplius 1期->約6小時->Nauplius 2期->約14.5小時*一尾母蟲所?的Nauplius 2期全部脫殼變成Copepodid所需的時間約3小時->Copepodid期->約2天沒有吸附在魚體上的Copepodid共活存期間約3-4天->Chalimus 1期->約8天->交配時?生（Female：5-7 Chalimus期；Male：Chalimus 7期）->約5天->成蟲（帶有卵莢）->約28小時->Nauplius 1期。 總計從卵孵出到達雌蟲成熟帶有卵曩需約15-18天的時間．整個實驗的進行，帶卵曩的成蟲被放置在直徑3.5公分的小皿中，到copepodid則改放到250ml燒杯中感染魚苗，以至下一期成蟲之出現．其培育所用的水鹽度為20?，溫度在24.5±0.5℃。

The study attempts to investigate morphological variation of developmental stages of the fish louse, Caligus sp., parasitic on Tilapia(Oreochromis mossambica). The results are submarized as follows: egg in sac (42 eggs be contained in egg sacs of one female worm)->approx. 1.5 hrs. (complete hatching)-> nauplius 1 stage->approx. 6 hrs.->nauplius 2 stage->approx. 14.5 hrs. *The molting time of all nauplius 2 stage in one worm needs: approx. 3 hrs.-> copepodid stage->approx. 2 days The survival period of copepodid that cann't parasited on fish: approx. 3-4 days.-> chalimus 1 stage->approx. 8 days->mating pair (Female:chalimus 5-7 stages male: chalimus 7 stage)-> approx. 5 days->adult (with egg sac)->approx. 28 hrs.->nauplius 1 stage. The period for life cycle commence from egg to adult stage carrying egg sac needs approximate 15-18 days. The experiment was performed using petri dishes 3.5cm in diameter each while the stages of worn are from adult with egg sac to early copepodid stage; after this, the culture of worm was changed to 250ml beakers to infect Tilapia fingerlings while the stages of worm are late copepodid stage and until the next adult with egg sac. The culture water was 20ppt salt water and the temperature was 24.5 ±0.5℃.