The attraction effects of hexahedral cone shaped artificial reef model on Plectorhynchus cinctus under three kinds of illumination

In this paper, a concrete-made artificial reef model with the shape of hexahedral cone was put into the experimental tank to observe the attraction effects of the artificial reef model on Plectorhynchus cinctus under three illumination conditions of natural illumination, 55 W and 26 W. The results showed that without the artificial reef model in the trough, the fish tended to stay in the areas on the left of the trough. The average occurring rate of the fish in these areas under the 3 different kinds of illumination were 61.60% (natural illumination), 81.61% (55 W) and 82.07% (26 W), but it was less than 5% inside the blank reef areas. After the artificial model was put into the troughs, the average occurring rate of the fish inside the reef areas increased to 37.60% (natural illumination),23.56% (55 W) and 15.75% (26 W), while that in the left areas of the trough reduced to 23.47% (natural illumination),71.61% (55 W) and 67.59% (26 W). The results showed that the hexahedral cone shaped artificial reef model had obvious attraction effects on P.cinctus under the three kinds of illumination, and the attraction effects reduced with the weakening of illumination.