Xn. Zhou et al., EFFECTS OF ICLOSAMIDE AND EUCALYPTUS-CAMALDULENSIS ON BIOMPHALARIA-GLABRATA, THE SNAIL INTERMEDIATE HOST OF SCHISTOSOMA-MANSONI, Journal of the Science Society of Thailand, 19(3-4), 1993, pp. 117-128
Toxicity studies were carried out on the snail Biomphalaria glabrata u
sing niclosamide (bayluscide) and the extract from dried leaves of Euc
alyptus camaldulensis. The snails were exposed to Niclosamide and to a
queous and methanolic extracts of E. camaldulensis for 24 h and recove
red for 48 h. In niclosamide, the LC50 and LC90 values were 0.063 and
0.126 mg/l, respectively. In aqueous extract, the LC50 and LC90 values
were 3049.65 and 5568.33 mg/l; while in methanolic extract, they were
71.59 and 96.73 mg/l. Histological changes were observed in the intes
tines, digestive glands and ovotestes of the molluscicides treated sna
ils. In the intestines, gaps were formed between the epithelial cells
and the connective tissue resulting in the derangement of the ciliated
cells. In the digestive glands, the digestive cells became irregular
in shape; and both digestive and calcium cells showed considerable shr
inkage. The ovotestes of the molluscicides treated snails showed reduc
tion in numbers of spermatozoa and oocytes.