2014 Volume 62 Issue 1 Pages 99-105
We examined the effects of a flow field in the rearing tank exhibited by different aeration rate and salinity gradient on the larviculture of the devil stinger Inimicus japonicus. Two different rearing experiments using 1 kl rearing tanks were conducted from hatching (day 0) to settlement. In the Experiment 1, fish were reared until day 21 in 5 different aeration rates (0-1200 ml/min). There was a significant and positive relationship between survival and aeration rate, and fish survival became stable at an aeration rate of more than 300 ml/min. In Experiment 2, the salinity gradient in a rearing tank was formed by pumping brackish water (22 ppt) from the surface and seawater (34 ppt) from the bottom at the same time. Control rearing tanks (34 ppt) were aerated at 300 ml/min and fish were reared until day 23. Growth and development was synchronized in the salinity gradient tanks with little standard deviation, although average survival at settlement in the salinity gradient tank (47.3%) was lower than the aeration tank (68.2%). The optimal aeration rate for devil stinger larviculture is stronger than 300 ml/min and introducing a salinity gradient can be a novel approach for enhancing performance of the fish.
