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Author Fried, B. ♦ Frazer, Betsy A. ♦ Reddy, Aditya
Source SpringerLink
Content type Text
Publisher Springer-Verlag
File Format PDF
Copyright Year ©1997
Language English
Subject Domain (in DDC) Social sciences ♦ Sociology & anthropology
Abstract A petri-dish bioassay was used to study the chemoattraction and penetration of the cercariae of Echinostoma trivolvis and E. caproni in the presence of snail dialysates from Helisoma trivolvis (Pennsylvania and Colorado strains), Biomphalaria glabrata, and Lymnaea elodes. Significant chemoattraction was seen with E. trivolvis cercariae in the presence of all snail dialysates released from nonperforated dialysis sacs with a molecular-weight exclusion of 12,000. Under the same conditions, E. caproni was significantly attracted to B.␣glabrata and H. trivolvis (CO strain) but not to L.␣elodes or H. trivolvis (PA strain). Dialysis sacs were perforated with needles to allow the release of snail substances of all molecular weights into the bioassay. Cercariae of both species were significantly attracted to all snail dialysates released from perforated sacs. Moreover, cercariae entered these sacs and penetrated the snails, and 24 h later the percentage of cysts per snail species ranged from 70% to 83% for E. trivolvis and from 73% to 93% for E. caproni. Dialysates released from intact sacs were extracted in choloroform-methanol (2:1) to obtain hydrophilic and lipophilic fractions. When these extracts were placed on agar plugs in the bioassay, the lipophilic fraction, but not the hydrophilic fraction, was mainly chemoattractive.
ISSN 09320113
Age Range 18 to 22 years ♦ above 22 year
Educational Use Research
Education Level UG and PG
Learning Resource Type Article
Publisher Date 1997-01-22
Publisher Place Berlin/Heidelberg
e-ISSN 14321955
Journal Parasitology Research
Volume Number 83
Issue Number 2
Page Count 5
Starting Page 193
Ending Page 197


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Source: SpringerLink