Zootaxa 20th Anniversary Celebration: section Acanthocephala

Evsyukov A.P., Potapenko I.O.

Introduction. The thorny-headed worms (Acanthocephala) are a small group of helminths, currently classified as a phylum. Adult helminths live in the intestines of various vertebrates. Eggs are excreted into the environment with feces, and in this way infest the arthropods, who are the intermediate hosts. The life cycles of some acanthocephala species can get complicated due to inclusion of the facultative, transport, paratenic or postcyclic hosts. Сhiropterans can be the definitive, intermediate or paratenic hosts for the various groups of parasitic worms, therefore they are an important link in the epizootic chains of spreading the invasive diseases. The aim of the articles of this series is to study the species composition of helminths parasitizing in bats of the Rostov Region. In the fourth paper of this series, we present data on thorny-headed worms and sum-up the previously published information.Materials and Methods. The research materials were the articles from the open access databases: PubMed (pubmed.ncbi.nlm.nih.gov), CyberLeninka (cyberleninka.ru), Google Scholar (scholar.google.com), BHL (www.biodiversitylibrary.org), JSTOR (www.jstor.org), etc. Some data were provided by the colleagues. Results. The list comprising three species of thorny-headed worms that can parasitize in bats in Rostov region was compiled. While analysing the literature sources, one more Nematoda species, not mentioned by us previously, was added to the list of nematodes.Discussion and Conclusion. The results of the review revealed that 15 bat species living in the Rostov region can be parasitized by 3 or 4 Acanthocephala species of 3 genera, 2 families and 2 orders. In total, 104 helminth species of three phyla can parasitize in chiropterans in the Rostov region: Nematoda, Platyhelminthes and Acanthocephala. Whereas, the largest number of parasites falls on the class Trematoda – 42 species. The largest number of helminth species was recorded in the serotine bat (54 species) and the common noctule (50 species). The least amount (4 species) – in the soprano pipistrelle. Our data show that the helminth fauna of bats in the Rostov region, Russia and in the world as a whole is still poorly studied. At the same time, some of the parasitic worm species distinguished in our research have the veterinary and medical significance, moreover, bats participate in the epizootic chains as the facultative hosts.

do Carmo W., Anjos L., Vrcibradic D.

Acanthocephalans, in their adult stage, are obligatory parasites of many types of vertebrates, including anuran amphibians. Their complex life cycle always involves an arthropod intermediate host but may include non-obligatory strategies that could improve transmission success, such as paratenic infections. In paratenic hosts, these parasites are normally found loose in the body cavity or encysted in internal organs. Here, we present the first report of acanthocephalans found encysted under the skin of an amphibian (i.e., external to its body cavity). The specimen, a clay robber frog [Haddadus binotatus (Spix, 1824)], had been collected in an Atlantic Forest area in southeastern Brazil. Upon examination of the frog, we recovered two specimens of acanthocephalan (Order Echinorhynchida) encysted under the skin of its venter. Considering the host’s relatively small size and its thin ventral musculature, we believe that the acanthocephalans may have accidentally trespassed the muscular tissue while attempting to encyst in the frog’s internal body wall.

Olivera L.A., Campião K.M.

Abstract Acanthocephalans constitute a small taxonomic group related to rotifers and specialized in a parasitic lifestyle. Anurans act as paratenic and definitive hosts and infections always occur trophically. Our objective is to describe and summarize the richness of acanthocephalans in Neotropical anurans. We conducted a literature review in the main research databases, compiling data published until August 2021. We identified 66 articles with records of acanthocephalan-anuran association, 53.03% were carried out in Brazil. We detected 108 species of anurans from 11 families parasitized by acanthocephalans. With the exception of Bufonidae, Hylidae and Leptodactylidae, which are relatively well-studied families, interaction with acanthocephalans remains largely unexplored for most anuran species. We found six families of acanthocephalans: Centrorhynchidae, Echinorhynchidae, Oligacanthorhynchidae, Cavisomidae, Neoechinorhynchidae and Plagiorhynchidae. Centrorhynchidae and Echinorhynchidae presented the largest number of taxa associated with anurans. The largest number of records corresponded to acanthocephalans in the larval stage (cystacanths), for which anurans act as paratenic hosts. We observed a lack of specific taxonomic resolution in the identifications of most reports, because a large part of the records in the larval stage make morphological identification difficult. Brazil, Mexico, Paraguay, Argentina, Ecuador and Peru are the countries with the most records, while Costa Rica, Venezuela, Colombia, Chile and Uruguay exhibited the lowest publication numbers, resulting in gaps in the distribution of acanthocephalans. We expanded the known number of anuran species parasitized by acanthocephalans, compared to the last published review. Overall, we aim to contribute to the understanding of diversity within this intriguing but understudied group.