Molecular studies involved in thermal stress for Dicentrarchus labrax, Sparus aurata and Oncorhynchus mykiss

Heat stress is a major environmental variable affecting survival, behavior, and physiology of fish, especially in the context of global climate warming. In recent years, research on heat stress in fish has expanded rapidly, focusing on both organism-level molecular responses and broader impacts on wild and farmed populations. Based on the literature, this review provides a holistic synthesis of molecular responses to heat stress in commercially significant fish species in Türkiye, namely Dicentrarchus labrax (Linnaeus, 1758), Sparus aurata (Linnaeus, 1758), and Oncorhynchus mykiss (Walbaum, 1792), associated with stress-protein induction (e.g., heat shock proteins), antioxidant defense modulation (e.g., superoxide dismutase, catalase activity), immune system alterations (e.g., pro-inflammatory cytokines), and metabolic adjustments. Understanding the genetic and molecular alterations that emerge under heat stress may contribute to strategies aimed at improving aquaculture performance in the face of ongoing thermal warming. This review may also serve as a useful reference for protecting fish health and production sustainability under intensifying thermal stress. Although previous reviews have addressed thermal stress in fish broadly, and in Mediterranean or aquaculture contexts, reviews jointly synthesizing the molecular heat-stress responses of D. labrax, S. aurata, and O. mykiss - particularly with reference to Turkish aquaculture - appear to be limited. This review may provide a practical and phased biomarker-based framework to support early-warning monitoring and climate-resilient management in Türkiye’s aquaculture sector.