Heat Shock Proteins in Aquatic Larvae: Nutritional and Live Feed Modulation of Chaperone‐Mediated Stress Physiology in Fish and Shellfish

ABSTRACT Heat shock proteins (HSPs) are highly conserved molecular chaperones that maintain proteostasis under environmental and physiological stress. In aquaculture research, HSP responses have been studied primarily in relation to temperature, salinity, pollutants, and pathogens in juvenile and adult stages, whereas the nutritional regulation of HSP dynamics during early larval development remains poorly resolved. This review synthesizes current knowledge on the functions and regulation of major HSP families (HSP100, HSP90, HSP70, HSP60, and small HSPs) in fish and shellfish larvae and develops mechanistic frameworks linking live feed characteristics to HSP‐mediated stress physiology. Drawing on evidence from Artemia and other crustacean and fish models, we propose a Live Feed–Proteotoxic Stress–HSP (LFP–HSP) axis that integrates feed digestibility, metabolic and oxidative load, and feed‐associated microbiota as key drivers of HSP induction and innate immune function. We further describe ROS–HSP–innate immunity crosstalk and introduce the concept of HSP‐conditioned resilience, whereby controlled, diet‐mediated HSP induction enhances larval tolerance to subsequent husbandry stressors and pathogen challenge. Comparative analysis of commonly used live feeds, including Artemia, rotifers, Moina, Daphnia, and copepods, indicates that differences in nutrient composition, structural complexity, and microbial associations generate distinct HSP expression profiles and stress phenotypes in consuming larvae. Finally, we discuss the application of HSP‐based biomarkers for live feed evaluation, larval quality assessment, and the development of feeding strategies that minimize chronic cellular stress while maximizing robustness in hatchery production of fish and shrimp.