Survival and growth of the black seahorse (Hippocampus kuda) cultured in diluted brine water

Abstract

Commercial aquaculture of seahorses has been repeatedly proposed as the solution to replace wild-caught seahorses, provide economic opportunities for fishermen in developing countries and to meet any future increase in global demand. However, the sustainability of commercial seahorse culture remains questionable due to vulnerability to diseases of this species. This study was conducted to assess the possibility of using diluted brine water for seahorse culture with a hope to improve bio security of the farming system. 315-ppt brine water was collected from salt paddies of Cam Nghia Salt Co-operative Company at Cam Nghia district, Khanh Hoa Province. The experiment included three treatments: (C) filtered sea water at salinity of 35-ppt (control), (B3 5 ) diluted brine water at salinity of 35-ppt, (B2 5 ) diluted brine water at salinity of 25-ppt. Each treatment had five replicate tanks with 10 seahorses/tank. The experiment lasted for 10 days. After 10 days of culturing, all seahorses in all treatments were died and the symptoms of dead seahorses in control treatment were matched well with the descriptions about the disease caused by virus in seahorse (Truong Sy Ky, in press). The symptoms of dead seahorses in both (B3 5 ) and (B2 5 ) diluted brine water showed differently comparing to control treatment. It is possible that the seahorses cultured in the diluted brine water may have died because of a harmful compound in brine water. More investigation is needed to fully assess the possibility of using diluted brine water for seahorse culture.

Keywords: seahorse, Hippocampuskuda, aquaculture, diluted brine water