Lymnaea schirazensis, an Overlooked Snail Distorting Fascioliasis Data: Genotype, Phenotype, Ecology, Worldwide Spread, Susceptibility, Applicability

BACKGROUND: Lymnaeid snails transmit medical and veterinary important trematodiases, mainly fascioliasis. Vector specificity of fasciolid parasites defines disease distribution and characteristics. Different lymnaeid species appear linked to different transmission and epidemiological patterns. Pronounced susceptibility differences to absolute resistance have been described among lymnaeid populations. When assessing disease characteristics in different endemic areas, unexpected results were obtained in studies on lymnaeid susceptibility to Fasciola. We undertook studies to understand this disease transmission heterogeneity. METHODOLOGY/PRINCIPAL FINDINGS: A ten-year study in Iran, Egypt, Spain, the Dominican Republic, Mexico, Venezuela, Ecuador and Peru, demonstrated that such heterogeneity is not due to susceptibility differences, but to a hitherto overlooked cryptic species, Lymnaea schirazensis, confused with the main vector Galba truncatula and/or other Galba/Fossaria vectors. Nuclear rDNA and mtDNA sequences and phylogenetic reconstruction highlighted an old evolutionary divergence from other Galba/Fossaria species, and a low intraspecific variability suggesting a recent spread from one geographical source. Morphometry, anatomy and egg cluster analyses allowed for phenotypic differentiation. Selfing, egg laying, and habitat characteristics indicated a migration capacity by passive transport. Studies showed that it is not a vector species (n = 8572 field collected, 20 populations): snail finding and penetration by F. hepatica miracidium occur but never lead to cercarial production (n = 338 experimentally infected). CONCLUSIONS/SIGNIFICANCE: This species has been distorting fasciolid specificity/susceptibility and fascioliasis geographical distribution data. Hence, a large body of literature on G. truncatula should be revised. Its existence has henceforth to be considered in research. Genetic data on livestock, archeology and history along the 10,000-year post-domestication period explain its wide spread from the Neolithic Fertile Crescent. It is an efficient biomarker for the follow-up of livestock movements, a crucial aspect in fascioliasis emergence. It offers an outstanding laboratory model for genetic studies on susceptibility/resistance in F. hepatica/lymnaeid interaction, a field of applied research with disease control perspectives

Europe, the United States and the Islamic World: Conceptualising a triangular relationship

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‘Animals just love you as you are’ : experiencing kinship across the species barrier

This paper explores how affective relationships between humans and animals are understood and experienced. It argues that, although the context of close relationships with pets has changed, affective relationships between humans and animals have a long history. The affinities between people and their pets are experienced as emotionally close, embodied and ethereal and are deeply embedded in family lives. They are understood in terms of kinship, an idiom which indicates significant and enduring connectedness between humans and animals, and are valued because of animals’ differences from, as well as similarities to, humans. Kinship across the species barrier is not something new and strange, but is an everyday experience of those humans who share their domestic space with other animals. Rather than witnessing a new phenomenon of post-human families, multi-species households have been with us for a considerable length of time but have been effectively hidden from sociology by the so-called species barrier

The Animals Went in Two by Two: Heteronormativity in Television Wildlife Documentaries

This article examines British television wildlife documentaries in order to outline the ways in which limited representations of animal behaviour recur. It focuses on representations of animal sexuality, monogamy and parenthood, and suggests that how such activities are repeatedly represented draw on normalised human notions of such behaviour. This is demonstrated through comparison of these representations with literature from zoology and ethology, which shows that a considerably wider variety of animal behaviour has been documented. The article suggests that the discourses of sexuality, monogamy and parenthood are interrelated and interdependent, with the validity of each supported by the existence of the others. It is argued that how animals are represented in such documentaries matters, partly because normalised discourses must be drawn on in order for programmes to make sense of the behaviour they present, but mainly because animal behaviour is commonly used as evidence for ‘natural’ forms of human behaviour