Discoloration of the Cephalothorax in Pandalus borealis and its Correlation with Internal Cadmium Concentration

Abstract

This study investigates the correlation between discoloration of the cephalothorax in Pandalus borealis (P. borealis) shrimp and cadmium concentration. The data, obtained through Atomic Absorption Spectroscopy (AAS), was converted into weight-based cadmium concentrations and analyzed using both parametric and non-parametric statistical tests. Despite assumptions of normal distribution not being met, a two-sample Students t-test and Mann-Whitney test were performed to examine the differences in cadmium concentrations between pink and discolored shrimp. Results indicated no statistically significant differences between the two groups. Experimental analysis revealed considerable overlap in cadmium concentration ranges for both groups, with high standard deviations. Factors such as the period of exposure to cadmium and potential influences from other contaminants or microorganisms were also considered. Previous studies have linked discoloration in shrimp to heavy metals and infections, but this study found no correlation between cadmium concentration and discoloration in P. borealis. The conclusion suggests that cadmium may not be a sole factor in shrimp discoloration, and other variables should be explored. Recommendations for future research include examining other trace metals, microbial infections, shrimp age, and extent of exposure to provide a comprehensive understanding of cephalothorax discoloration in shrimp.