Clearance of Escherichia coli by the freshwater mussel Lamellidens marginalis in laboratory conditions

ABSTRACT

Scientists and environmentalists are searching for biological remedies to reduce E. coli concentrations in waterbodies to acceptable levels. The present research was conducted to investigate clearance of E. coli isolated from freshwater mussels (Lamellidens marginalis) in the Old Brahmaputra River, Mymensingh, Bangladesh by conspecific mussels from the same river in aquarium conditions. Mussels were acclimated, depurated and divided into three shell length (SL) groups. Small (38.28 ± 2.81 mm), medium (47.28 ± 1.52 mm) and large (55.89 ± 2.25 mm) mussels were assigned to aquaria designated as T₂, T₃ and T₄ respectively whereas empty mussel shells were assigned to T₁ as control in triplicate. After addition of pure E. coli suspensions, 3 mL water samples from each aquarium were collected at hourly intervals for 12 h for total E. coli count (TEC). Statistical analysis revealed that both time and treatments have significant effects (P < 0.05) on TEC. Presence of live mussels caused 1.41–1.63 log₁₀ reduction of TEC after 12 h compared to the control. However, such differences were not consistent among the different SL groups. In conclusion, L. marginalis is capable of reducing E. coli concentrations although the efficacy is not consistently related with mussels’ shell lengths.

KEYWORDS:

• Aquarium
• biological remedy
• faecal coliform
• Unionidae

Acknowledgments

The authors would like to express sincere thanks and gratitude to the reviewers for their critical comments and valuable guidelines for improving the manuscript.

Disclosure statement

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

Additional information

Funding

This project was funded by Bangladesh Fisheries Research Institute (BFRI), project number 2018/521/BFRI to Md. Jasim Uddin, Department of Fisheries Management, Bangladesh Agricultural University, Mymensingh which belongs to a development project ‘Conservation, Propagation and Culture of Mussels and Snails in Bangladesh’ funded by Ministry of Fisheries and Livestock , Bangladesh.