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Displacement of Biomfhalaria glabrata by thiara granifera under natural conditions in the Dominican Republic

Abstract

After a study of the population dynamics of Biomphalaria glabrata snails in several breeding places in the Dominican Republic, the snail Thiara granifera was introduced in some B. glabrata habitats. T. granifera became established in one point in one habitat in the townof Quisqueya, in the east of the country. Around this point of establishment 6 points were selected in order to observe the population dynamics of both species of snails and the chemical and biological characteristics at each point. Four of these points already harbored B. glabrata. One control point was selected also harboring B. glabrata. After 14 months of observations, the results showed that T. granifera was competing with and displacing B. glabrata. This competition does not seem to be competition for food or vital space. Rather, B. glabrata avoids the presence of T. granifera and moves away to new areas, and this is possibly due to a chemical substance(s) secreted by T. granifera or by physical contact with the large number of individuals of T. granifera.

Biomphalaria glabrata; Thiara granifera; displacement; biological control; schistosomiasis mansoni; Dominican Republic


ABSTRACT

Displacement of Biomfhalaria glabrata by thiara granifera under natural conditions in the Dominican Republic

Jose Gomez Perez1

Mercedes Vargas1

Emile A. Malek2

Universidad Autonoma de Santo Domingo, Facultad de Ciencias, Instituto de Investigaciones, Dominican Republic

Tulane Medical Center, Department of Tropical Medicine, WHO Collaborating Center for Applied Medical Mlacology. Laboratory of Schistosomiasis and Medical Malacology, New Orleans, USA

After a study of the population dynamics of Biomphalaria glabrata snails in several breeding places in the Dominican Republic, the snail Thiara granifera was introduced in some B. glabrata habitats. T. granifera became established in one point in one habitat in the townof Quisqueya, in the east of the country. Around this point of establishment 6 points were selected in order to observe the population dynamics of both species of snails and the chemical and biological characteristics at each point. Four of these points already harbored B. glabrata. One control point was selected also harboring B. glabrata. After 14 months of observations, the results showed that T. granifera was competing with and displacing B. glabrata. This competition does not seem to be competition for food or vital space. Rather, B. glabrata avoids the presence of T. granifera and moves away to new areas, and this is possibly due to a chemical substance(s) secreted by T. granifera or by physical contact with the large number of individuals of T. granifera.

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Publication Dates

  • Publication in this collection
    15 June 2009
  • Date of issue
    Sept 1991
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