Morphological and molecular characterization of brown-banded broodsacs and metacercariae of Leucochloridium (Trematoda: Leucochloridiidae) parasitizing the semi-slug Omalonyx unguis (Succineidae) in Argentina.

Trematodes of the genus Leucochloridium exhibit an unusual transmission strategy among mollusks (intermediate host). The fully developed sporocyst, housing encysted metacercariae, displays vivid coloration and rhythmic activity in the snail's tentacle, mimicking insect larvae. These strategies attract insectivorous birds, their final hosts, thereby increasing the chances of completing their life cycle. In South America, the reports of adults and larval stages of Leucochloridium are scarce. Brown-banded broodsac of Leucochloridium sp. were obtained from Omalonyx unguis collected in a shallow lake from Corrientes Province, Argentina. Here, we morphologically characterized the larval stages (broodsac and metacercaria), identified the parasite through DNA sequences from nuclear 28S-rRNA (28S) and the mitochondrial cytochrome c oxidase I (COI) genes, and explored its evolutionary affinities with the Leucochloridium species available in GenBank. The present broodsac displays brown bands, with a yellowish background in the first two-thirds and yellowish-white in the last third. Based on morphological comparisons, the broodsac and metacercaria described in this study could not be conclusively categorized under any known South American species of Leucochloridium. In relation to the phylogenetic reconstructions, Leucochloridium sp. consistently clustered with L. perturbatum, and species delimitation analyses resulted in recognized Leucochloridium sp. from Argentina as a distinct species. The DNA sequences obtained in this study constitute the first genetic data generated for sporocyst broodsacs in South America. Future studies, incorporating morphology, genetic, and biological data, will be essential for both species identification and the elucidation of leucochloridiid diversity in the region.

Manipulative neuroparasites: uncovering the intricacies of neurological host control.

Manipulative neuroparasites are a fascinating group of organisms that possess the ability to hijack the nervous systems of their hosts, manipulating their behavior in order to enhance their own survival and reproductive success. This review provides an overview of the different strategies employed by manipulative neuroparasites, ranging from viruses to parasitic worms and fungi. By examining specific examples, such as Toxoplasma gondii, Leucochloridium paradoxum, and Ophiocordyceps unilateralis, we highlight the complex mechanisms employed by these parasites to manipulate their hosts' behavior. We explore the mechanisms through which these parasites alter the neural processes and behavior of their hosts, including the modulation of neurotransmitters, hormonal pathways, and neural circuits. This review focuses less on the diseases that neuroparasites induce and more on the process of their neurological manipulation. We also investigate the fundamental mechanisms of host manipulation in the developing field of neuroparasitology, which blends neuroscience and parasitology. Finally, understanding the complex interaction between manipulative neuroparasites and their hosts may help us to better understand the fundamentals of behavior, neurology, and host-parasite relationships.

Finding of an Unusually Colored Sporocyst of the Genus Leucochloridium in a Succinea putris Snail.

A Leucochloridium sp. Carus, 1835 sporocyst with a mature colored broodsac was found in a Succinea putris L., 1758 snail in the Boksitogorsk district of Leningrad Region (Russia). The pigmentation of the sporocyst's broodsac was different from those of other Leucochloridium Carus, 1835 species previously described for Europe. The obtained sporocyst is most similar by the coloration of its broodsac to the trematodes of the same genus from Japan. The genotyping of the investigated sporocyst by the rDNA gene fragments (complete ITS1, ITS2, 5.8S and partial 18S and 28S sequences) was conducted. Genetic distances between the obtained sporocyst and the previously described species of the genus Leucochloridium were higher than intraspecific ones in the most cases. These data and the data of morphological analysis imply that the investigated sporocyst belongs to a separate species of the Leucochloridium genus, previously not described in the European region.

Multiple infection of amber Succinea putris snails with sporocysts of Leucochloridium spp. (Trematoda).

Amber Succinea putris snails were collected in the Leningrad Region (Russia). Some of them were infected with trematodes Leucochloridium paradoxum, Leucochloridium perturbatum and Leucochloridium vogtianum. One snail had triple infection with all these species. Genotyping of sporocysts by ITS1-5.8S-ITS2 nucleotide sequences of ribosomal DNA (rDNA) and phylogenetic analysis were performed. The results confirmed the species identification of sporocysts of Leucochloridium based on the shape and colour of mature broodsacs. Sporocyst broodsacs could leave the host snail on their own, remaining viable in the environment for up to an hour. This ability of sporocysts may prevent the excessive infection of the molluscan host.

Helminth Community Structure of Tits Cyanistes caeruleus and Parus major (Paridae) during Their Autumn Migration on the Southern Baltic Coast.

The research problem undertaken in this study is to determine the scale of infection of Eurasian blue tit Cyanistes caeruleus and Great tit Parus major and the biological diversity of their internal parasites, helminths. The aim of the study is to gain new knowledge about the structure of the helminth communities of the Eurasian blue tit and Great tit on the southern coast of the Baltic Sea during autumn migration to their wintering grounds. Helminths of tits were collected in 2008-2012 on the southern coast of the Baltic Sea in Poland. PAST v. 2.11 software was used for the calculations. Barcoding DNA was used to identify trematodes initially classified based on morphological characters to the genera Leucochloridium and Urogonimus. Cestodes Anonchotaenia globata were recorded for the first time in Poland. The Eurasian blue tit is a new host in Poland for three species of helminths: cestode Monosertum parinum and filarial nematodes, Cardiofilaria pavlovskyi, and Diplotriaena henryi. The Great tit is a new host in Poland for trematode Urogonimus macrostomus, cestode A. globata and M. parinum, and filarial nematode Diplotriaena obtusa. The nematode C. pavlovskyi was the species most frequently recorded in both host species. A high degree of similarity was found between the component communities and infracommunities of helminths in Eurasian blue tit and Great tit. The new information provided in this study has increased our knowledge of the transmission of helminths in Central Europe.

An unknown species of Leucochloridium (Trematoda: Leucochloridiidae) from northern Honshu, Japan.

Pulsating broodsacs of Leucochloridium sp. (Trematoda: Leucochloridiidae) were found from amber snails (Succinea lauta) in Iwate, the northern part of Honshu, Japan. A pattern with red-brown vertical stripes was characteristic of the broodsac. Very similar broodsacs were already detected from Okinawa Islands, the southern archipelago of Japan, and tentatively identified as Leucochloridium cf. passeri. A phylogenetic analysis based on DNA sequences of mitochondrial cytochrome c oxidase subunit 1 (cox1) showed that Leucochloridium sp. is different at species level from L. cf. passeri and that both species are related to Leucochloridium vogtianum from Europe. In this study the definitive identification of larval Leucochloridium sp. was impossible, but the resulting phylogeny confirmed that at least 4 species of Leucochloridium are distributed in Japan, depending on locality and climate. The DNA barcode generated in this study will be useful in detecting the adult stage of Leucochloridium sp. from birds.

Molecular identification of the broodsacs from Leucochloridium passeri (Digenea: Leucochloridiidae) with a review of Leucochloridium species records in Taiwan.

Leucochloridium spp. have been established in Taiwan since the 1930s, with five species listed: Leucochloridium turdi, Leucochloridium passeri, Leucochloridium muscularae, Leucochloridium sime, and Leucochloridium taiwanese listed until now. Because of the similar morphology among the adults of the Leucochloridiidae family, the taxonomic status of most of them should be reconsidered. Broodsacs are the most distinct characteristic shared by Leucochloridium flukes, and L. passeri is, by far, the only one whose broodsacs have been described. In this study, broodsacs collected from an infected Succinea sp. (amber snails) in Taiwan were morphologically compared to previous descriptions and sequenced using both nuclear and mitochondrial genetic markers for identification. Our samples resembled broodsacs of L. passeri previously described in northern Taiwan and those recently collected in Okinawa, Japan. The conspecific status of the broodsacs collected in Taiwan and Okinawa was supported by the identical DNA sequences identified in this study. Broodsacs have rarely been reported in tropical and subtropical regions, although some Leucochloridium spp. have been recorded. In such cases, genetic markers will be crucial to link Leucochloridium broodsacs in snails (intermediate host) with their corresponding adult stage in birds (definitive host).

Distribution records of three species of Leucochloridium (Trematoda: Leucochloridiidae) in Japan, with comments on their microtaxonomy and ecology.

Insectivorous birds serve as definitive hosts for trematodes of the genus Leucochloridium. The parasites exclusively use amber snails of the family Succineidae as intermediate hosts. A pulsating and colorful display of the larval broodsac in the snail's eyestalk seems to be a caterpillar mimic for attracting birds. A colored design of the broodsac is very useful for parasite identification. In Japan, characteristic broodsacs from amber snails have been recorded from 1980's, but their taxonomic discrimination from Asian, European, and North American species has not been achieved. In this study, old scientific records, sighting information on broodsacs from the general public, and direct molecular evidence by DNA barcoding clearly showed that at least three species of Leucochloridium are distributed in Japan. A vertical-striped broodsac found from Succinea sp. in Okinawa, the subtropical island of Japan, were treated as Leucochloridium sp., but being almost identical to that of Leucochloridium passeri in neighboring Taiwan. The European species of Leucochloridium perturbatum and Leucochloridium paradoxum were frequently detected from Succinea lauta in Hokkaido, the northernmost island of Japan. The former species was common in inland areas of Hokkaido, whereas the latter species was frequently seen in the coastal areas. A possible explanation for the parasite distribution pattern is that principal definitive hosts (migratory or resident birds) differ in each parasite. The conspecificity of Leucochloridium variae in North America and L. perturbatum in Europe and the Far East is also discussed.

Morphological and genetic characterization of green-banded broodsacs of Leucochloridium (Leucochloridiidae: Trematoda) sporocysts detected in Succinea lauta in Hokkaido, Japan.

Green-banded broodsacs of Leucochloridium sporocysts were obtained from land snails, Succinea lauta, collected in Esashi, Esashi District, Hokkaido, Japan. The broodsacs were similar to those of L. paradoxum, which have never been found on the Japanese archipelago. Here, we compare morphological and molecular genetic characteristics of the green-banded broodsacs to those of L. paradoxum. The broodsacs described in this study and those of L. paradoxum showed three equal parts; however, band characteristics of the second parts differed. Moreover, the sequences of nuclear 18S and 28S rRNA genes of the Leucochloridium flukes were not identical with those of L. paradoxum, and the sequences of the mitochondrial cytochrome c oxidase subunit 1 gene were paraphyletic to the species. These findings suggest that the broodsacs described in this study were distinct from those of L. paradoxum. In the future, genetic analyses on adult flukes from avian hosts should be performed, upon precise identification according to morphology, in order to clarify relationships between adult flukes and sporocysts of Leucochloridium species occurring in Japan.