Effects of materials, incubation time and colors of artificial shelters on behavior of juvenile sea cucumber Apostichopus japonicus

In the present studies, the effects of various artificial shelters on behavior of juvenile sea cucumber, Apostichopus japonicus, were evaluated. The preferences of animals in the experiments with eight different artificial material shelters were compared, and showed that shelters of stone, cement pipe, polywoven fabric (a synthetic woven material mainly composed of polypropylene), ceramic tile and PVC (polyvinylchloride) pipe attracted significantly more animals than low-pressure polyethylene pipe, wood block and corrugated PVC board (P < 0.05). The influences of shelters pre-incubation for 0.5 M (month), 1 M, 1.5 M and 2 M to grow biofilm on the shelter selection of the animals were compared with non-incubation shelters (0 M), and showed that the numbers of the animals attracted by incubated shelters were significantly greater than that without incubation, and the 1.5 M shelters attracted significantly more sea cucumbers than other treatments (P < 0.05) except 2 M (P > 0.05). Among six color shelters white shelter attracted less juvenile A. japonicus than green, red and blue ones, and there were no significant differences among white, yellow and black shelters (P > 0.05).