APPLICATION OF UV LIGHTS ON LARVAL REARING MEDIA FOR ABALONE (Haliotis squamata)
The common problem in abalone (Haliotis squamata) culture is seed availability, due to its low survival rate at larval stages. Thus, this research aimed at studying the effect of UV light applied in rearing water on survival rate of abalone larvae. This research was conducted at Marine Aquaculture Development Center (MADC) Lombok from March to June 2015. About 900.000 trochophores were reared in a 10 ton-concrete tank and two UV lights were placed on inlet with low debit flow. These larvae were cultured for 4 months and fed with live diets such as Nitzchia sp, Amphora sp dan Navicula sp.
The result showed survival rate of abalone larvae reared in UV-treated water was higher than abalone larvae reared in water without UV treatment: 0.8% and 0.6% respectively. Additionally, total bacterial counts (TBC) in rearing water treated with UV lights were significantly lower than TBC in untreated water, 1.15 x 104 CFU/ml and uncountable/ml bacteria in untreated water respectively. These results indicated that UV light could increase survival rate of abalone larvae by killing significant numbers of bacteria including potential bacterial pathogens in rearing water. Range of water qualtiy: salinity 33-34 ppt, temperature 29-30 °C, DO 3,5-4,5 mg/l, pH 7,5-8 dan NH3 0,1-0,2 mg/l.