Comparative Bioaccumulation of Mineral Elements in Soft Tissues, Shells, and Pearls of Sinohyriopsis cumingii (Lea, 1852) Cultured for Non-Nucleated, Visceral Mass-Nucleated, and Mantle-Nucleated Pearls

The triangle sail mussel Sinohyriopsis cumingii (Lea, 1852) is the world’s leading producer of freshwater pearls. Mineral elements are key components of pearls and affect pearl quality, but their bioaccumulation patterns in the soft tissues, shells, and pearls of this species remain unclear. Inductively coupled plasma mass spectrometry was used to compare the bioaccumulation of essential major elements (Na, Mg, K, Ca), essential trace elements (Cr, Mn, Fe, Co, Ni, Cu, Zn, Se, Mo), and non-essential elements (Al, As, Sr, Ag, Cd, Ba, Tl, Pb) in the soft tissues, shells, and pearls of S. cumingii cultured for non-nucleated, visceral mass-nucleated, and mantle-nucleated pearls. Mg, K, Mn, Zn, and Ba were significantly more concentrated in soft tissues than in shells or pearls, whereas Ca and Sr showed the opposite trend (p < 0.05). Principal component analysis based on Zn, Ca, Mg, Sr, and Mn separated soft tissues from shells and pearls, while a second component based on Mo, Fe, Co, and Ni distinguished non-nucleated from visceral mass-nucleated and mantle-nucleated pearl mussels. Ca–Sr and Sr–Ba were consistently positively correlated in soft tissues across all three culture types (p < 0.05). Notably, Na was frequently involved in negative correlations between tissues: in mussels cultured for non-nucleated pearls, shell Na was negatively correlated with soft tissue K and pearl Na with soft tissue Ba (p < 0.05); in those cultured for visceral mass-nucleated pearls, soft tissue Na was negatively correlated with pearl Mn and Zn (p < 0.05); and in those cultured for mantle-nucleated pearls, pearl Na was negatively correlated with shell Zn (p < 0.05). Collectively, these findings elucidate mineral element bioaccumulation in pearl-producing S. cumingii.