Sex-specific differences in metallothionein induction by cadmium in different organs of Donax trunculus Linnaeus, 1758

ABSTRACT

To investigate the impact of heavy metals on the physiology of aquatic organisms, previous studies have focused on selected biomarker measurements in samples. However, most studies do not take into account toxicity effects on both males and females. The present paper aims to examine the effect of sex on the detoxification response using metallothioneins (MTs), a biomarker of metallic contamination. MTs were measured in different organs (mantle, digestive gland and gonad) of both males and females of Donax trunculus L. (Mollusca, Bivalvia) exposed to cadmium (Cd). The samples were collected at El Battah beach, far from any source of pollution, and reared in the laboratory for four days. Cd was added to the rearing water at two previously determined sublethal concentrations (LC₁₀ and LC₂₅). Measurements of MTs were made at (0, 48 and 96 h). Cd exposure caused a significant induction (P < 0.05) of MTs in all studied organs in both sexes with a marked effect in females. The digestive gland had the highest MT levels, followed by the gonad and then mantle. Female and male individuals of this species differ in their susceptibility to Cd. This study supports the importance of sex and tissue in ecotoxicological studies.

KEYWORDS:

• Biomarker
• digestive gland
• female
• gonad
• heavy metals
• male
• mantle
• molluscs

Acknowledgements

The authors wish to thank anonymous referees for useful discussions and critical reading of the manuscript. This study was conducted as part of a PRFU project (Pr. N. Soltani), and was supported by the National Fund allocated to Research Laboratory of Applied Animal Biology (University Badji Mokhtar, Annaba).

Disclosure statement

No potential conflict of interest was reported by the author(s).