Study of the Behavioral Characteristics of Lutjanus erythropterus on the Basis of the Distance and Structure of Artificial Reefs

The aims of this study were to analyze the preferences of rocky reef fish for different types of artificial reefs and to determine the distances between reefs that lead to the production of independent effects. In this study, the aggregation behavior of juvenile <i>Lutjanus erythropterus</i> was observed under different reef spacings (0.5 L (distances of 0.5 times the reef length), 1.0 L, 1.5 L, 2.0 L, 2.5 L, and 3.0 L). The results revealed that when the distance between the reefs was 0.5 L, the juvenile fish presented frequent between-reef activity, and their attraction to the reefs was significant. When the distance between the reefs was 2.5 L or 3.0 L, the number of juvenile fish appeared to significantly differ between the areas. The number of juvenile fish farther from the reefs was relatively low, and the value tended to plateau. The results revealed that the two reefs had a combined effect when the reef distance was 0.5 L, 1.0 L, 1.5 L, or 2.0 L, whereas the two reefs had independent effects when the distance was 2.5 L or 3.0 L. In addition, to determine the distance at which the reefs had independent effects, the preference of juvenile <i>L. erythropterus</i> for different reef types was investigated, and the behavior of <i>L. erythropterus</i> was observed when two or four reefs (room-shaped artificial reef, RAR; lobe-shaped artificial reef, LAR; cubic artificial reef, CAR; and stacked artificial reef, SAR) were placed in an experimental tank at the same time. The results showed that in the experiments where two or four different reef models were present, juvenile <i>L. erythropterus</i> preferred the cubic artificial reef. At this reef, the fish exhibited the strongest reefing behavior and stayed for the longest time. This study reveals the reefing behaviors of juvenile <i>L. erythropterus</i> under different reef spacings and their preferences for various artificial reef models, providing a theoretical basis and reference for the design and selection of habitats for related species and of artificial reef models for marine pastures.