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

## TL;DR

This study examines how different distances and structures of artificial reefs affect the behavior of juvenile Lutjanus erythropterus, offering insights for better reef design and marine conservation.

## Contribution

The study identifies optimal reef spacing and preferred reef types for juvenile Lutjanus erythropterus, contributing to improved artificial reef design.

## Key findings

- Juvenile Lutjanus erythropterus showed significant attraction to reefs when spaced at 0.5 L.
- Cubic artificial reefs were the most preferred by the fish, with the strongest reefing behavior observed.
- Reefs spaced at 2.5 L or 3.0 L had independent effects, while closer reefs showed combined effects.

## Abstract

With the further study of marine ecological protection and sustainable fishery development, artificial reefs, an effective means of marine ecological engineering, have gradually become the focus of research. Artificial reefs can not only provide marine organisms with habitats and breeding and foraging sites but also help promote the recovery and stabilization of marine ecosystems and increase their production. In this study, Lutjanus erythropterus was used as a target to analyze aggregation behavior comprehensively under different reef spacings and behavioral responses in the presence of many different types of reefs simultaneously. This study helps to understand the ecological needs of juvenile L. erythropterus more accurately, provides a scientific basis for optimizing the design and layout of artificial reefs, has a positive impact on the protection and proliferation of reef fish resources, maintains the balance of the marine ecosystem, and promotes the sustainable development of marine fisheries.

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 Lutjanus erythropterus 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 L. erythropterus for different reef types was investigated, and the behavior of L. erythropterus 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 L. erythropterus 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 L. erythropterus 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.