Effect of mercuric chloride on terrestrial slug Semperula maculata and histopathology of reproductive organs: a comprehensive study

Abstract

Since the last few decades, terrestrial diversity is found to be under stress due to the contamination by various chemicals and gases of aquatic and agricultural media. The bioaccumulation of these compounds at certain concentrations in different tissues produces histopathological changes leading to behavioral changes in target animals. This study focused on terrestrial molluscan slug, Semperula maculata, against lethal concentrations of mercury chloride (HgCl₂). Bioaccumulation of Hg was highest in ovotestis, while lowest in the molluscan penis. Histopathological changes were observed in the cellular arrangement of reproductive organs. Alterations in the penis and the dart gland included dilated unicellular, multicellular glands, and muscular dystrophy, dilated peripheral glandular cells, respectively; dilation being maximal in the prostate gland. Ovotestis showed depleted number of gametocytes. Vacoulized pre-vitellogenic oocytes with early vitellogenic oocytes were noted under light microscopy. Mercury produced toxicity on secretory functions and lowered the rate of reproduction in animals. Evidence indicates that Hg produced gamete degeneration, impacted reproductive capacity and survival of this species in the ecosystem.

Keywords:

• mercury chloride
• slug Semperula maculata
• bioaccumulation
• behavioral changes
• histopathology
• gametogenic cells

Acknowledgments

The authors are thankful to the Head, Department of Zoology, Shivaji University, Kolhapur for providing facilities in the progress of work.

Disclosure statement

No potential conflict of interest was reported by the authors.