Asian Transactions on Basic & Applied Sciences

Volume: 03, Issue: 01, March 2013
ISSN 2221-4291

Title: Laboratory and Semi-field Evaluation on the Biological Control of Oncomelania hupensis Snail (Gastropoda: Pomatiopsidae), Using Sesarmops intermedium Crab (Decapoda: Grapsidae)
Author(s): Yassir Sulieman and Theerakamol Pengsakul
Paper ID: ATBAS-40307010
Pages: 1 - 5
Abstract: Sesarmops intermedium is a semi-terrestrial crab in tropical and subtropical regions, inhabits grasslands, freshwater pools and rivers offshore. The crab was evaluated as a potential biological control agent against Oncomelania hupensis snail, the intermediate host of Schistosoma japonicum. Both sexes of the crab of different sizes were allowed for 24 h to feed upon three different snail sizes: < 5 mm; 5-7 mm; and >7 mm, in the laboratory, and outdoors in simulated semi-field conditions. The crab fed mostly on small and medium-sized snails (< 5 mm, 5-7 mm) in the laboratory as well as in the semi-field microcosms. Large male and large female (mean carapace width 26.9 mm) S. intermedium crab consumed more snails than the small male (mean carapace width 19.9 mm). Only large male and female crab were able to crush and consume snails that were >7 mm in size. The snail predatory efficiency of crab positively correlated with its carapace width; with the rates of snail consumption increasing with increasing carapace width. The results indicated that S. intermedium crab was efficient in reducing O. hupensis snail populations through predatory interaction, as evidenced by the laboratory as well as semi-field assessment.

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