Dynamics of tissue minerals reveal the priority deposition of ovarian minerals during ovarian maturation of Chinese mitten crab Eriocheir sinensis

Minerals are essential for crustacean growth, development, and reproduction. This study investigated fluctuations in concentrations of twelve minerals in the hepatopancreas, ovary, and muscle of adult female Chinese mitten crabs (Eriocheir sinensis) throughout ovarian maturation (stages II-V), and explored potential mineral transfers between tissues and associated mineral-related gene expression patterns. Results showed a significant increase in five macro-minerals (Na, K, Ca, P, Mg) and most trace minerals (except Fe, Co, Mo) in the ovary (P < 0.05). In contrast, most minerals in the hepatopancreas, including Ca, P, Zn, Mn, Se, Co, and Mo, decreased significantly, while Fe and Cu concentrations increased markedly (P < 0.05). Muscular minerals exhibited varied trends, with Na, K, and Mg increasing significantly (P < 0.05). Ovarian mineral concentrations were positively correlated with the gonadosomatic index (GSI) (P < 0.001), while most hepatopancreatic minerals exhibited a negative correlation with GSI (P < 0.001). Significant correlations were also observed between different minerals in the hepatopancreas, ovary, or muscle (P < 0.05). Additionally, mineral-related genes mt-1β (metallothionein-1β-like) and fer (ferritin-like) were upregulated in both the ovaries and hepatopancreas, showing negative correlations with Ca, P, Mg, Zn, and Mn in the hepatopancreas (P < 0.05) and positive correlations with K, Ca, P, Mg, Cu, Zn, Mn, and Se in the ovary (P < 0.01). In conclusion, the major findings suggest that most minerals are dynamically accumulated in ovary and muscle during the ovarian maturation cycle of E. sinensis, with a potential mineral accumulation and transfer mechanism from the hepatopancreas to the ovary.