Effects of Organic Fertilizer on Hepatic Lipid Levels and
Cholinesterase Activity in Channa punctatus (Bloch).
Susanta Nath1*, Chiroprotim Saha2,
Himadri Sekhar Bhowmick2, and Valerio Matozzo3
1Government G. D. College, Singur, West Bengal, India.
2Department of Zoology, Bidhannagar College
EB-2.Sector-1 Kolkata-700 064, India
3Department of Biology, University of Padova,
Via Ugo Bassi 58/B, 35131 Padova, Italy
The effects of mustard oil cake (MOC) on liver lipid levels and brain cholinesterase activity of Channa punctatus (Bloch) were assessed. Due to excessive use, these organic fertilizers enter the freshwater ecosystem as runoff during irrigation and heavy rain, reaching concentrations higher than those required in the rearing pond. Fish were exposed to 0.42 mgl-1 MOC for 35 days. The results reveal that liver lipid levels were higher during exposure in both control and treated fish when compared to 0 day levels. Lipid levels decreased slightly after 21 (in both treated and untreated fish) and 35 days (in untreated fish). Results also showed an increase in brain cholinesterase activity in MOC-exposed fish.
Key words: brain, Channa punctatus, cholinesterase, lipid, liver, mustard oil cake
With the increase of human habitat and conspicuous agriculture and fishery practices, organic pollution is now considered to be a major trouble in many regions of the world (Randall and Tusi 2002). In particular, fertilizers are used in ponds to increase the production of plankton, both autotrophic and heterotrophic levels which augment fish production. Meanwhile, a combination of mustard oil cake (MOC), cattle-dung and poultry manure (6:3:1) at 11 000 kg/ha is also effective for the production of zooplankton in carp nursery ponds (Grag and Bhatnagar 2000; ICAR 2006).
Organic fertilizers are commonly used in agriculture and fisheries in India and other parts of the world. Organic fertilizers are considered to be pollutants in aquatic ecosystems, mainly due to the indiscriminate and extensive uses. To identify the neurotoxicity of chemicals such as organophosphorus and carbamate pesticides, measurement of cholinesterase (ChE) activity was previously used as a biomarker of neurotoxicity (Matozzo et al. 2005; Narbonne et al. 2005).