Apostichopus japonicus was reared under different temperatures,salinities and light cycles so as to analyze the effects of temperature,salinities and light cycle on the growth and behavior of it.A.japonicus were sampled from Dakoujing Shrimp Cultural Cage,Lüshun City,which were 1-year-old,and were accustomed to the experimental conditions for two days before each experiment.The average initial body wet weight of the experimental sea cucumber was 36.89 g(25.24-59.11 g),and the average initial body length was 6.68 cm(5.12-8.74 cm).In the temperature experiment,the sea cucumbers were reared in six plastic barrels(the cubage of each was about 60 L and one brick in each barrel) at six temperatures(9,12,15,18,21 and 24 ℃).The results showed that the body wet weight increased under 9-21 ℃ and 15 ℃ was the optimum temperature to the growth of A.japonicus.When the temperature was beyond 22 ℃,A.japonicus began to aestivate.As soon as the temperature below 20 ℃,aestivation was over.In the salinity experiment,the sea cucumbers were reared in the same plastic barrels under six salinities(23,26,29,32,35 and 38).The salinity for growth of the A.japonicus was 29-33,and the optimum salinity was 32,the reason of which was that the sea cucumbers had been accustomed to the range of salinity in the ocean for a long time.The A.japonicus were reared in four plastic barrels for the light cycle experiment,and the conditions of the barrels were fully light (24-hour-light),fully dark(24-hour-dark),half light dark(12-hour-light and 12-hour-dark) and natural light.The growth of the sea cucumbers was best under the half light dark condition,and worst under the fully dark condition.In addition,the correlation analyses were given in each experiment.
