Tissue-specific mercury (Hg) content in mantis shrimp (Squilla mantis) from the Central Adriatic Sea (GSA 17): A reproductive stage perspective

Mercury (Hg) contamination in marine species is a critical environmental and public health issue, particularly for commercially important resources like mantis shrimp, Squilla mantis. This study assessed Hg levels in muscle and gonadal tissues of 64 female S. mantis from the Adriatic Sea, assessed into pre-spawning, spawning, and post-spawning reproductive stages. Hg concentrations in S. mantis varied across reproductive stages, with the highest levels in muscle during spawning and the lowest during post-spawning. An opposite trend was found in gonadal tissue. Muscle consistently contained more Hg than gonads, and significant positive linear correlations between the two tissues were observed across reproductive stages. Hg accumulation in muscle was also related to carapace length and gonad weight in specific stages. Hg concentrations measured in muscle and gonad tissues (0.110 ± 0.006 and 0.035 ± 0.001 mg kg^-1 wet weight, respectively) were below the maximum limits established by the European Union for seafood safety (0.5 mg kg^-1).