Total volatile basic nitrogen (TVB-N) content is one of the critical safety evaluation indexes in seafood . This study investigated the colorimetric sensing array (CSA) technique with two data collection blocks, imaging and visible near-infrared spectroscopy, for non-destructive prediction of TVB-N content in Fujian oysters. Three data fusion strategies coupled with variable selection approaches including variable combination population analysis (VCPA), ant colony optimization, and competitive adaptive reweighted sampling were applied to establish the partial least squares (PLS) model for predicting the TVB-N content of oysters. Better prediction performance was obtained using data fusion of two information blocks than using individual block data. The results showed that the high-level-VCPA strategy showed the best performance with the correlation coefficient of the prediction set (R p ) at 0.9128. This work demonstrates that the use of CSA has the potential for non-destructive monitoring of TVB-N content in Fujian oysters.
Thyroid hormones (THs) are key regulators of early development and metamorphosis in vertebrates, implying possible developmental roles in invertebrates. Given the importance of embryonic growth and survival to oyster seed quality and aquaculture success, understanding TH function during oyster embryonic development is therefore essential. This study investigated the effects of thyroxine (T4) concentration and exposure duration on the embryonic and larval development of Fujian oyster ( Crassostrea angulata ) . T4 was administered both by immersing female broodstock and by directly exposing embryos to T4-enriched seawater. Additionally, thiourea was used to inhibit endogenous TH synthesis in broodstock, followed by T4 treatment of their embryos. Each concentration-duration treatment was performed in triplicate, with 0.01 N NaOH serving as the vehicle control. Results showed that low to medium T4 concentrations (1.29 × 10 −9 mol/L, 1.29 × 10 −8 mol/L, 1.29 × 10 −7 mol/L) significantly enhanced the hatching rate and shell length (μm) of D -shaped larvae compared to controls ( P < 0.05). In contrast, high T4 concentrations (1.29 × 10 −5 mol/L, 1.29 × 10 −6 mol/L) exhibited significant inhibitory effects ( P < 0.05), which intensified with prolonged exposure durations. Using a validated Chemiluminescence immunoassay, results indicated that prolonged exposure may lead to cumulative T4 accumulation, contributing to developmental inhibition. Compared to direct embryonic exposure, the maternal approach potentially appeared to mitigate the inhibitory effects associated with direct high-dose exposure. Additionally, in the 1.29 × 10⁻⁸ mol/L group, an elevated triiodothyronine to T4 ratio was observed from the cleavage to the blastula stage, potentially explaining the observed developmental advantages. In conclusion, this study clarifies the dose- and time-dependent regulatory roles of T4 in early bivalve embryogenesis. While limited to the D -larval stage, these findings provide preliminary theoretical insights into TH dynamics that may inform future aquaculture seed production strategies.
危险品化学品经营许可证（带存储）