The relationship between habitat physical complexity and recruitment of the coral reef damselfish, Pomacentrus amboinensis:: an experimental study using small-scale artificial reefs

A manipulative experiment using small-scale artificial reefs was conducted to quantify the relationship between habitat physical complexity and recruitment of the coral reef damselfish Pomacentrus amboinensis, at Urasoko Bay, Ishigaki Island (Ryukyu Islands, Japan), from January to July 2000. Four types of small-scale, structurally different artificial reefs, including (1) vertical bars with three layers of horizontal bars (type A), (2) vertical bars with a single layer of horizontal bars (type B), (3) vertical bars only (type C), and (4) no bars (type D), were employed for the experiment. Although the peak numbers of P. amboinensis recruits on most of the artificial reefs were recorded on 9 June, the mean number of recruits per replicate varied depending on the reef types. The mean number of recruits on type A was significantly greater than those on the other types, whereas no difference between types B and C were found, and only a few juveniles were observed on type D at one observation time. The experiment demonstrated that the degree of habitat structural complexity had a significant impact on the number of P. amboinensis recruits.