Goussia Labbé, 1896 (Apicomplexa, Eimeriorina) in Amphibia: Diversity, Biology, Molecular Phylogeny and Comments on the Status of the Genus

We provide new data on morphology, host specificity, life history, pathology and phylogeny of the coccidian genus Goussia in European anurans. Divergence in the SSU rDNA sequences (3–4%) of three Goussia isolates from three anuran hosts suggests that the isolates represent three distinct species. The isolate from Pelophylax kl. esculentus was determined as Goussia neglecta. The isolates from Rana dalmatina and Rana temporaria are considered conspecific and are, on the basis of host specificity, light microscopical, ultrastructural, and molecular phylogenetic data, described as a new species, Goussia noelleri. The new Goussia species from Bufo bufo remains unnamed. During the host's metamorphosis the infection disappears, however, oocysts are retained in the liver of post-metamorphic frogs. Molecular phylogenetic analysis showed that anuran-host Goussia form a well-supported monophyletic clade, which together with a clade represented by piscine Goussia metchnikovi, constitute basal lineages of the Eimeriidae. The two lineages show polytomy, likely reflecting undersampling of the basal eimeriid taxa. Goussia janae represents a distinct lineage, sister to the clade containing the other eimeriorinid taxa, suggesting a paraphyly of the genus Goussia. The identity of G. neglecta, the status of the genus Goussia, the presence of cryptic species in anuran-host Goussia and their ecological peculiarities are discussed.