Oswaldocruzia ukrainae (Nematoda: Molineidae)—A Parasite of European Green Toad Bufotes viridis: Morphological and Molecular Data

Abstract

Nematodes of the genus Oswaldocruzia are common parasites of the small intestine of amphibians and reptiles. Our recent molecular analysis of Oswaldocruzia nematodes revealed that only Oswaldocruzia filiformis, which possesses high morphological variability, parasitizes amphibians and reptiles in European Russia. Here we present the study of Oswaldocruzia nematodes from the European green toad Bufotes viridis (Anura, Bufonidae) collected at different localities of the Middle Volga region in 2018–2022. We analyzed the morphological characteristics of the Oswaldocruzia spp. taxonomy together with novel molecular phylogenetic data. The data on phylogenetic analysis (based on partial CoxI mtDNA gene sequences) showed that Bufotes viridis is parasitized by two Oswaldocruzia species, the host-specific parasite Oswaldocruzia ukrainae and species generalist Oswaldocruzia filiformis. Broad morphological variability was revealed in O. ukrainae nematodes both from the same host specimen and from various toad individuals from different localities. Our results highlight the need for further biodiversity research of morphologically similar Oswaldocruzia species from amphibians and reptiles in the Western Palearctic using molecular genetic methods.

Oswaldocruzia franciscoensis n. sp. (Nematoda: Molineidae) in Leptodactylus macrosternum Miranda-Ribeiro, 1926 (Anura: Leptodactylidae) from Caatinga morphoclimatic domain, Brazil: morphological and molecular characterisation

“…Furthermore, phylogenetic approaches to representatives of Molineidae are limited since they include few species or are focused only on certain genera (De Bellocq et al 2001;Chilton et al 2006;Kirillova et al 2023). In relation to Oswaldocruzia, the situation may be considered more critical because only five out of 90 species have been genetically characterised, namely, O. belenensis Santos, Giese, Maldonado & Lanfredi, 2008, O. chabaudi Ben Slimane & Durette-Desset, 1996, O. chambrieri Ben Slimane & Durette-Desset, 1993, and O. filiformis and O. ukrainae Ivanitzky, 1940, in addition to several sequences labelled as Oswaldocruzia sp., in which makers for cox1 are by far the most common (see Willkens et al 2016;Kirillova et al 2020Kirillova et al , 2023. Therefore, the currently limited genetic evidence does not allow further conclusions about the phylogeny of Oswaldocruzia.…”

“…2016; Kirillova et al . 2020, 2023). Therefore, the currently limited genetic evidence does not allow further conclusions about the phylogeny of Oswaldocruzia.…”