The global astaxanthin market reached $1.69 billion in 2024, with 47% directed to aquafeed—yet the molecular basis of its absorption, metabolism, deposition, and storage in aquatic organisms remains incompletely resolved. A deeper understanding of these mechanisms will help optimize feed formulations, enhance astaxanthin bioavailability, and improve economic efficiency in aquaculture. This study investigates the absorption mec...

Animal gut microbiomes—comprising bacteria, archaea, fungi, viruses, and protozoa—are fundamental to host evolution, physiology, and ecosystem resilience. This review synthesizes 21st-century advances in their diversity, spatiotemporal dynamics, and functional roles across the animal kingdom. Although high-throughput metagenomics has transformed the field, major biases remain: most studies still focus on domesticated vertebrat...