PEMIJAHAN BUATAN TERIPANG PUTIH SEBAGAI UPAYA PELESTARIAN HOLOTHUROIDEA DI KEPULAUAN KARIMUNJAWA

Abstract

At present the demand of seacucumber (Holothuria ecabra) as export commodity is increasing. The supplies are thoroughly from natural stock. The continued exploitation constitues a severe treat to the natural populations. Therefore it is urge to do an attempt to increase the population of seacucumber by cultivating them. The result will not only be benefit for fishermen, but it also could be restocked onto their natural habitat (sea ranching). It is of importance for producing larvae continuously and conservation purposes, induced spawning of seacucumber as first step of their culture are studied. The present work was being part of two stage research (two years) which was aimed to understand the processes of induced spawning of White Seacucumber, to determinate best method of induced spawning, to produce sand seacucumber larvae and to seek the possibility of conserving the natural stock in Karimunjawa Islands. The experiment was conducted on selected broodstock (healthy and wieght > 400 grams) which were induced spawned by environmental manipulation ie. thermal shock, desiccation and combination of those two methods. Preliminaryu study also was done on induced spawning of seacucumber by chemical stimulation using KC1 and H20" Fertilised eggs then were observed up to early auricularia stage. On the next research ( Stage II or second year), research will be stressed on larvae culture. The result of present work revealed that seacucumbers were able to be induced spawning using environmental manipulation, ie. thermal shock, desiccation and their combination but the outcome was different. The effect of thermal shock on male and female spawned were better (100 % and 80 %) compare to other method (60 % and 30 % for desiccation and 30 % dan 10 % for combination). Combination of thermal shock and desiccation seemed to stress the broodstocks physically and physioloically, therefore gave the worst result. Percentage of early auricularia larvae developed from fertilised eggs was propotional with achievement of broodstock spawned ie. 90.29 %, 87.27 % and 37.96 % for thermal shock, desiccation and its combination respectively. In addition, chemical stimulation using KCl and 8202 were able to induced spawning seacucumber. The result was 80 % and 7D % male spawned and 60 dan 40 4 female spawned. Although it seemed better than desiccation or combination of thermal shock and desiccation stimulation, it needed to be observed more deeply.