Studies And Effectiveness Comparison On Important Structural Parameters Of Artificial Reef For The Sea Cucumber

Apostichopus japonicas,Selenka is an important mariculture species in China. The research and development of artificial reef for the sea cucumber has become an issue to be solved urgently. This paper reviews the behavioural ecology characteristics of A.japonicas and the general situation of artificial reef for the sea cucumber development. And then,a series of simulating lab tests are conducted to compare the effects of important structural parameters of artificial reef for the sea cucumber. Results indicate that important structural parameters exert an influence on the behavior of aggregation through variation of light intensity. Thus,targeted research on behaviors of aggregation and the growth under different light intensities was carried out. The main research results are summarized as follows:1,Effectiveness comparison on important structural parameters of artificial reef for the sea cucumberFrom complex structural of artificial reef for the sea cucumber,four important parameters (aperture,interval spacing,colour,included angle ) were chosen to be modeled in order to craft four kind of reef models, and every kind of reef models was divide into different levels(aperture reef models have four levels: 2cm,4cm,8cm,16cm;interval spacing reef models have four levels: 2cm,4cm,6cm,8cm;colours reef models have six levels: black,red,blue,green,white,transparent;included angle reef models have six levels: 15°,30°,45°,60°,90°,120°). By mean attractive rate(MAR) method,compare each level of each structural parameter in this paper. The results showed that: (1) The MAR of artificial reef models showed an up trend with the lapse of time. (2) The MAR of artificial reef models were significantly higher under natural light than under darkness. (3) The MAR was in the order of 2cm> 4cm,16cm> 8cm of different aperture reef models,2cm> 4cm> 6cm> 8cm of different interval spacing reef models,black,red,blue> green> white> transparent of various colours reef models,and 15°> 30°> 45°,60°> 90°,120°of different included angle reef models. Thus,the sea cucumbers ranging from 10 g to 30 g,which showed negative phototaxis,had time to adapt to the artificial reef models and had better selective for 2cm aperture,2 cm spacing,dark colour,15°included angle than the other key indicators in artificial reef structure design.2,Influence on aggregation under different light intensityAdopting white sea cucumbers and green ones as experimental subject,the experiment took Total Light Intensity value (TLI) as a statistical analysis index to study the influence on aggregation under different light intensity. Experimental results show that: both white and green sea cucumbers showed negative phototaxis . Green ones are more sensitive to intense light than white ones,while white ones have higher endurance to intense light than green ones.3,Influence on growth under different light intensityUsing the breeding cage,compared the influence on growth under different light intensity. Adopting white sea cucumbers and green ones as experimental subject,experimental results show that: Under natural conditions,green sea cucumber grew faster than white ones. The control group,which lived under natural light,grew faster than the other groups.