Miracidial infectivity of Hypoderaeum conoideum (Trematoda: Echinostomatidae): differential susceptibility of two lymnaeid species

Abstract

A study was made of the infectivity of Hypoderaeum conoideum miracidia to a range of laboratory-reared specimens of freshwater snail species (Lymnaea peregra, L. corvus, Physella acuta, and Gyraulus chinensis) that coexist with the parasite in the same natural habitat. L. peregra and L. corvus were found to be equally susceptible to the parasite when specimens of each snail species were singly exposed to miracidia. However, when miracidia could choose either lymnaeid species, they showed a high degree of specificity toward L. peregra. The results obtained suggest that H. conoideum miracidia are capable of distinguishing among these lymnaeids in their orientation to the host. This indicates that miracidia might achieve specificity before actually contacting the snail host and suggests that during the host-snail orientation process they respond to signals different from those generated upon snail contact and invasion. The specificity toward L. peregra observed in H. conoideum miracidia seems to indicate adaptation to the snail community in their natural habitat, resulting in enhancement of their transmission.

Mediterranean essential oils as effective weapons against the West Nile vector Culex pipiens and the Echinostoma intermediate host Physella acuta: what happens around? An acute toxicity survey on non-target mayflies

“…1a) and the invasive freshwater snail Physella acuta (Draparnaud) (Mollusca: Physidae) (Fig. 1b), an important intermediate host for many parasites (Toledo et al 1999(Toledo et al , 2000Faltýnková 2005;Faltýnková and Haas 2006;Muñoz-Antoli et al 2006Barragán-Sáenz et al 2009;Kraus et al 2014), including the worldwide distributed trematode Echinostoma revolutum Looss (Echinostomida: Echinostomidae) and the nematode Parastrongylus cantonensis (Chen) (Rhabditida: Angiostrongylidae) (Hai et al 2009). The acute toxicity of A. millefolium and H. tuberculatum was also assessed on a non-target aquatic organism sharing the same ecological niche of C. pipiens larvae and P. acuta snails, the nymphs of the mayfly Cloeon dipterum L. (Ephemeroptera: Baetidae) (Fig.…”

Foodborne Intestinal Flukes in Southeast Asia

“…Freshwater snails, Planorbis corneus, Indoplanorbis exustus, Lymnaea stagnalis, Lymnaea limosa, Lymnaea ovata, and Lymnaea rubiginosa, shed the cercariae, and snails and tadpoles are the second intermediate hosts [48,201]. Lymnaea tumida in Russia [202] and Lymnaea peregra and Lymnaea corvus in Spain [203] were experimentally proven to be potential first intermediate hosts. In Thailand, this echinostome was reported from humans and birds [201,204].…”

Echinostomes in humans

“…Lymnaea peregra and Lymnaea corvus in Spain (Toledo et al 1999) were also experimentally proven to be the potential first intermediate hosts. In Thailand, H. conoideum was reported from humans and birds in Thailand (Yokogawa et al 1965 ;Harinasuta et al 1987) .…”