Scales of Freshwater Fish Labeo rohita as Bioindicators of Water Pollution in Tung Dhab Drain, Amritsar, Punjab, India

Abstract

This study examined the impact of municipal wastewater on scale morphology of freshwater fish Labeo rohita. Fish were exposed to sublethal concentrations (17.7, 26.6, or 35.4%) of municipal wastewater for durations of 15, 30, and 60 d. Recovery experiments were also performed for a duration of 60 d. Scales were extracted after respective exposure periods, cleaned, and processed for scanning electron microscopy. Results showed concentration- and exposure duration-dependent alterations in the morphology of scales. Severe damage was observed at the anterior and posterior portions of scales in the form of lepidontal breakage and uprooting, destructions at the base of circuli and radii along with complete structural loss in the focal region and adjacent circuli and radii, and alterations in structure of tubercles. Data indicate that scales of fish L. rohita may be employed as bioindicators of water pollution and could be incorporated into water monitoring surveillance.

Additional information

Funding

The authors thank University Center of Emerging Life Sciences facility of Guru Nanak Dev University, Amritsar, for Scanning Electron Microscopy, and the University Grants Commission, New Delhi for providing the financial support.