While short-term faba bean feeding is known to improve fish texture, its long-term systemic effects and the underlying molecular mechanisms in Nile tilapia remain rarely explored. This knowledge gap is critical, given the potential for extended feeding to induce distinct metabolic reprogramming and trade-offs. Here, we present the first comprehensive study investigating the 180-day impact of a 60% FB-based diet (FBD) on Nile tilapia through an integrated analysis of phenotypic traits, muscle histology, metabolome, and transcriptome. Our results revealed a fundamental trade-off: FBD feeding induced hyperplasia-driven muscle remodeling, significantly enhancing textural properties (hardness, gumminess, chewiness) and increasing intramuscular fat and collagen content, but at the cost of suppressed growth and hepatosomatic index. Metabolomics identified 243 significantly altered metabolites, outlining a systemic metabolic shift characterized by activated lipid synthesis but inhibited amino acid and energy metabolism. This multi-omics integration nominated the chac1 gene as a novel key regulator for FB-induced muscle hyperplasia, a finding not previously reported in this context. We propose a mechanistic model wherein long-term FBD feeding coordinates lipid deposition, collagen accumulation, and chac1-mediated hyperplastic growth to remodel muscle texture. Our work provides new insights into the long-term metabolic trade-offs and molecular drivers of FB-induced flesh quality improvement, offering a theoretical foundation for developing optimized aquafeeds.

In this study, we conducted an exploration of blood collection, hematological and biochemical comparative analysis of the unique vitreous humor and blood of the celestial-eye goldfish (CE) (Carassius auratus), and obtained hematological and biochemical indicators for healthy celestial goldfish blood. After exploring the optimal method for collecting blood and ocular fluid, blood and vitreous humor samples were drawn from healthy CE, and an automatic hematology analyzer was used to measure 17 physiological indicators in the blood and vitreous humor. Additionally, 20 biochemical indices were measured by an automatic biochemical analyzer. Experiments were also conductedto evaluate the effect of blood and vitreous humor collection on the subsequent survival rate of the CE. The results showed that the blood of CE exhibited values for 17 hematological indicators, including red blood cells (mean value: 2.19 × 10¹²/L), white blood cells (mean value: 62.21 × 10⁹/L), hemoglobin (mean value:138.25 g/L), and no eosinophils or basophils. We also found that the levels of aspartate amino transferase (AST) and glutamyl transpeptidase (GGT) in the vitreous humor of CE were significantly higher than those in the serum (p < 0.01). No cells were detected in the vitreous humor of CE, and there was no significant difference in survival rate compared to normal goldfish after extracting blood and vitreous humor from CE (p > 0.05). This study provides fundamental data for the cultivation of healthy goldfish, the development of goldfish hematology, and further research on the development and formation of CE’s unique eye traits.