Effect of dietary dihydromyricetin on overwintering of large yellow croaker (Larimichthys crocea)

Abstract

The large yellow croaker (Larimichthys crocea) is a warm current migratory fish that experiences significant metabolic challenges during winter due to low temperatures and food shortages, leading to increased mortality rates. This study aimed to evaluate the effects of dihydromyricetin, a natural flavonoid, on the wintering performance of large yellow croakers. Over a 60-day period, fish fed dihydromyricetin showed improved growth rates and enhanced tolerance to low temperatures and water flow rates. A quadratic regression analysis of the relationship between specific growth rate (SGR) and dietary dihydromyricetin intake confirmed that at a feeding level of 205.4 mg/kg, the SGR reached a maximum of 1.07. Transcriptomic and metabolomic analyses indicated that dihydromyricetin activates the PPAR signaling pathway, which optimizes fatty acid metabolism and contributes to increased cold tolerance. Additionally, the supplementation improved the fish’s antibacterial and anti-inflammatory responses, essential for maintaining health under stress conditions. Notably, the addition of dihydromyricetin did not alter the diversity of the intestinal microbiota, suggesting that it enhances immunity without disrupting gut health. These findings provide valuable insights into the potential of dihydromyricetin as an effective dietary supplement to improve the overwintering survival and overall health of large yellow croakers in aquaculture settings. Implementing this strategy could significantly reduce winter mortality rates and promote sustainable practices in fish farming.