Major Viral Diseases of Penaeus Monodon in Taiwan

Abstract

Preliminary results are reported on an automatic manipulation system for the masspropagation and chromosome manipulation of the small abalone,Haliotis diversicolor.The system was designed based on the optimum conditions obtained from tests simulatingthe possible conditions during automatic manipulation.Small abalone eggs couldwithstand seawater and air exposure for up to 210 min and 80 min,respectively,beforefertilization.Fertilized eggs could accumulate up to 0.8 cm thick for 60 min withoutdamage.Transfer of the fertilized eggs through outlet pipes up to 4 m in length did notresult in visible damage or decline in hatching rate.Fertilized eggs were not resistant tocontinuous rotation at 150,200,or 250 rpm for 20 min.The rotating drum speed of theautomatic manipulation system within 40 rpm and the pump flow at 30±3 liter/min wererecommended.Effect of aeration and stirring of the rotating drum on the fertilized eggswithin the concentration tank improved hatching rates.The final design of the automaticmanipulation system incorporated these features.The automatic control box of thesystem ensures that specific treatments,such as those for chromosome manipulation,canbe precisely carried out.As a whole,the system has been found highly applicable forregular mass propagation and chromosome manipulation procedures of the small abaloneand is the first one of its kind.