Impact of Cold Stress and Toxicants on Urea Excretion of Earthworms

Urea excretion in P. posthuma was analyzed with reference to five different media like distilled water, NaCl, Na2CO3, CuSo4, ZnSo4, 1 hour after exposure. Earthworm excreted 76-83 mg/100 ml urea in distilled water at room temperature and 57.14mg/100ml of urea at 5-10Ëšc in another, 58.33 mg/100 ml urea was excreted in 1% NaCl solution at 5-10Ëšc and 55.55 mg/100 ml urea in 1% Na2CO3 solution at 5-10Ëšc, 54.54 mg/100 ml urea in CuSo4 solution which contain 0.001g of CuSo4 in 100 ml distilled water at 5-10Ëšc, 71.48 mg/100 ml urea was excreted in ZnSo4 at 5-10Ëšc. At 5-10Ëšc earthworm live for 1hour in distilled water, 1% NaCl and 1% Na2CO3, but exhibited discomfort after 1 hour the same solutions at normal temperature. In CuSo4 and ZnSo4 they were stressed after 15-16 minutes because of toxicity intolerance, decline in values of urea excreted under different stress situations was noted. Severe stress was caused by ZnSo4 and CuSo4 toxicants. This is probably due to alterations in body metabolism, this may affect growth, water and salt balance and reproduction of this detrivore. So, conservation of worms against toxicants is suggested for maintaining the soil fertile.