Effect of different stocking densities on fish growth performance: A meta-analysis

Abstract

Density is an important aquaculture parameter which has a remarkably impact on variable fish growth performance. However, many scattered studies of density on individual fish have hindered understanding of its roles in growth of fish from different families. The present study attempted to explore the effects of density on fish growth. We found two levels of the optimal density and corresponding weight via density-weight fitted curve: 0-28 g body masses with the optimal densities from 1.76 to 14.55 kg·m−3; 7.17–98.33 g body masses with the optimal densities from 14.55 to 38.38 kg·m−3. The forest plots indicate that the most fish SGR values were significantly improved in low density. However, high heterogeneities were found in above four parameters. But no obvious publication bias was found in survival, CF, SGR and FCR, suggesting that the high heterogeneities is originated from animals, diet and experimental design. The Principle Component Analysis (PCA) further validated that the optimal density is one of the most key factors and it has obvious negative correlation with several Temperature/Dissolved oxygen, suggesting relevance among density, growth, and water quality/feeding regime. We speculated that the density could strongly influence fish growth through altering hematological and plasmatic phenotypes. We further focused on two of three pivotal enzymes, the CS, IDH, are highly possible in response to overcrowding stress in Kreb's cycle and they could further affect fish growth. This study explored the correlation between optimal density and fish body masses for the first time. Current results will provide theoretical guidance for fish growth and healthy aquaculture.