More efficient allopatric combinations of Fasciola hepatica and Lymnaea truncatula due to modification of redial development?

Abstract

Experimental infections of two susceptible French populations of Lymnaea truncatula (Courcelles and Saint Ours) with an allopatric (FeÁ s, Morocco) or a semi-sympatric (Limoges, France) isolate of Fasciola hepatica miracidia were performed to determine the effect of allopatric miracidia on redial and cercarial production. In both populations, cercarial release was signi®cantly greater in allopatric than in semi-sympatric snails. Compared to semi-sympatric snails, the examination of allopatric snails killed from day 14 to day 35 post-exposure demonstrated (1) a signi®cant decrease after day 28 in the number of daughter rediae (R2a group) exiting from the ®rst-appearing mother redia (R1a redia), and (2) the dierentiation of numerous daughter rediae (R2b group) in the body of second-appearing mother rediae (R1b group). These experiments demonstrated that the exposure of L. truncatula to an allopatric isolate of miracidia disturbed the usual developmental pattern of redial generations and caused the formation of numerous R2b rediae. The authors hypothesized that the increase in cercarial release noted in allopatric snails would be assured by the rediae from the R2b group after their emergence from the body of R1b mother rediae.

Sympatric and allopatric combinations ofLymnaea columellaandFasciola hepaticafrom southern and south-eastern Brazil

“…The geographical race to which parasites and hosts belong may influence the result of infections. Associations may be sympatric if the hosts and parasites are from the same area, or allopatric if they involve parasites and hosts from different localities (Goumghar et al , 2001). The influence of sympatric and allopatric host–parasite associations has been investigated in other countries (Gasnier et al , 2000; Goumghar et al , 2001) but there have been no studies investigating this effect in snail populations from distinct regions of Brazil.…”

“…Associations may be sympatric if the hosts and parasites are from the same area, or allopatric if they involve parasites and hosts from different localities (Goumghar et al , 2001). The influence of sympatric and allopatric host–parasite associations has been investigated in other countries (Gasnier et al , 2000; Goumghar et al , 2001) but there have been no studies investigating this effect in snail populations from distinct regions of Brazil. The objective of this study was to compare the susceptibility of L. columella from the southern and south-eastern regions of the country to infection with F. hepatica in sympatric and allopatric host–parasite relationships.…”

Fasciola hepaticain Cuba: compatibility of different isolates with two intermediate snail hosts,Galba cubensisandPseudosuccinea columella

“…snail ecology, parasite and snail genetic diversity, definitive host management). Sympatric combinations of snails and parasites have been found to be more (Osnas & Lively, 2011) or less efficient (Goumghar et al , 2001). Local adaptation in this interaction has been reviewed by Hurtrez-Boussès et al (2001).…”

Sympatric and allopatric experimental infections of the planorbid snailGyraulus chinensiswith miracidia ofEuparyphium albuferensis(Trematoda: Echinostomatidae)

“…In digenetic trematodes, very few studies on parasite–snail first intermediate host compatibility are centred on one parasite strain with one sympatric snail species and its comparison using allopatric strains of the same snail species (‘local’ or ‘at home’ vs. ‘foreign’ or ‘away’ results, according to the terminology proposed by Greischar & Koskella, 2007). Most of these studies deal with parasite strains of different origins and one snail species (sympatric or allopatric), or with one parasite strain and snails of different species (sympatric or allopatric) (Tchuem Tchuenté et al , 1999; Gasnier et al , 2000; Southgate et al , 2000; Goumghar et al , 2001).…”