Page 131 - RUT Publisher

Life Science Research and Sustainable Development ISBN: 978-98-84663-33-9

Impact of Heavy Metals (mercuric chloride, copper sulphate and

zinc sulphate) on Survivability of Earthworms

Dr. Vaidya V. V. and Dr. Jadhav S. S.

Dept. of Zoology
Smt. S. K. Gandhi Arts, Amolak Science & P.H. Gandhi Commerce College, Kada, Tq. Ashti, Dist.
Beed

Keywords: Abstract:
Perionyx Earthworms play a major role in enhancing the physical, chemical,
excavatus, and biological properties of soil. They are considered as keystone
Heavy Metals, species within ecosystem and are used extensively as bio indicators of
toxicity environmental contamination. The survival rate of earthworm
gradually decreased in all media with an increase in concentration of
heavy metals. The observed lethal dose (LD50) for 24, 48, 72 and 96 h
were ascertained to be 9, 6, 4 and 3 mg/100 g soil respectively of
mercuric chloride. 59, 35, 18 and 10 mg / 100 g of soil respectively of
copper sulphate and 140, 70, 35 and 17 mg per 100 g of soil
respectively of zinc sulphate. The graphically ascertained lethal dose
(LD50) values with the help of regression analysis for 24, 48, 72 and 96
h were found to be 9.509, 6.13, 4.798 and 3.017-mg/100 g soil for
mercuric chloride, 59.533, 35.343, 18, 0904 and 10.339 mg/100g of soil
for copper sulphate and 140.012, 70.3217, 35.0017 and 17.8053-mg/100
g of soil for zinc sulphate. The present study revealed that survival of
worms Perionyx excavatus declined with an increase in the proportion
of concentration added and with exposure time. Heavy metals impose
negative impact on growth of earthworms.

Introduction
Earthworms are ubiquitous animals living in soils, enhancing chemical and physical
properties and the distribution and activity of microbes and soil animals. In addition, it has been
reported that after earthworm activity, the fraction distribution of heavy metals Cu, Zn, Cr, Cd
and Pb is changed significantly, thus affecting the bioavailability of these metals Wen et al., (2004).
Over 80 % of the biomass of terrestrial composed of earthworms. They play a vital role in the
decomposition of organic matter in soil and form an important link in the food chain by
channelizing waste energy from dead and decaying organic matter to higher tropic levels by
being a prey for terrestrial vertebrates and birds. Through their feeding, burrowing and casting
activities, they also improve soil quality nutrient uptake plant growth, and plant yield.
Earthworms have a particularly intimate contact with the soil, consuming large quantities of soil
and having few external barriers to the soil solution. For these and other reasons, earthworms
have been used extensively in ecotoxicological soil studies Sivakumar (2015). Earthworms are one
of the important soil macro invertebrates and they function as consumers, decomposers, soil
modulators, and food resources for other animals.
Earthworms ingest the metals through feed or by dermal uptake which are known to
negatively affect the physiological functions. Heavy metal is a widely distributed metalloid

https://jesjalna.org/Zoology-Publications/index.html 123 Department of Zoology, J. E. S. College, Jalna