11International Centre for Ecological Engineering and Department of Ecological Studies, University of Kalyani, Kalyani- 741235, West Bengal, India.
2Department of Zoology, Sreegopal Banerjee College, Bagati, Mogra, Hooghly- 712148, West Bengal, India,
Biological indicators are species that can be employed to monitor environmental quality and ecosystem health. Different groups of organisms such as plants, animals, bacteria and parasites regularly produce certain molecular signal in response to changes in their environmental milieu. Parasites are important tools for providing wealth of information on physicochemical quality, environmental stressors, trophic interactions, population structure, biodiversity, etc. Given that environmental degradation impacts occurrence frequency and intensity of fish parasites, they may serve as sensitive living probes to monitor environmental factors and ecological status of the water body. Population dynamics of parasites of fresh water fish have been studied involving several host species infected by monogenetic parasite, Gyrodactylus sp. The parasitological parameters such as prevalence, mean intensity, mean abundance of parasite were used for such aquatic biomonitoring purpose. There appeared to be distinct variation on parasitization, relationship between host and prevalence of infection. The present study indicates significant interaction between water quality variables and parasitism. Temperature seems to be the most important abiotic parameter that affected parasitic prevalence and load of infection. Under the pH range and dissolved oxygen level as encountered in the polluted sites, fish became stressed and vulnerable to be affected with parasitic infection. The present study presents a comprehensible view on how Gyrodactylus sp. can be championed as a sensitive and meaningful model for aquatic environmental study and effective management tool for aquatic biomonitoring.