EFFECTS OF A PYRETHROID INSECTICIDE CYPERMETHRIN ON BENTHIC OLIGOCHAETE WORM, Branchiura sowerbyi (BEDDARD, 1982)

Chandan Sarkar; Nimai Chandra Saha

Volume : VI, Issue : VII, July - 2017

EFFECTS OF A PYRETHROID INSECTICIDE CYPERMETHRIN ON BENTHIC OLIGOCHAETE WORM, Branchiura sowerbyi (BEDDARD, 1982)

Chandan Sarkar, Nimai Chandra Saha

Abstract :

The present study was done to evaluate the acute toxic effects of Cypermethrin to benthic oligochaete worm, Branchiura sowerbyi along with the changes in their behaviour during the study. The 24, 48, 72 and 96 h LC₅₀ values of Cypermethrin to B. sowerbyi were 3.18, 2.30, 1.70 and 0.75 mg/l respectively. The rate of mortality of B. sowerbyi varied significantly (p<0.05) at 24, 48, 72 and 96h of exposure time. The mortality rate of the worm also varied significantly (p<0.05) with all exposed concentrations of the toxicant except 3.2-4.0 mg/l at 72 and 96h. The worm showed different behavioural responses like abnormal clumping tendency, less movement and excessive mucous secretion which were recorded during the study at all exposure times.