Raquel de Oliveira Simões’s research while affiliated with Federal Rural University of Rio de Janeiro and other places

We describe a new species of the genus Alippistrongylus (Nematoda: Trichostrongylina) in the small intestine of Delomys dorsalis (Rodentia: Sigmodontinae) found in Itatiaia National Park (Parque Nacional do Itatiaia, PNI), state of Rio de Janeiro, Brazil. The new species can be distinguished between the other two species previously described by the following morphological characteristics: pattern of the rays from the caudal bursa rays in males and the spherical-shaped appendage in the female. Additionally, we provide molecular genetic data from the new species. The discovery of Alippistrongylus itatiaiaensis sp. n. expands our understanding of nematode diversity and underscores the importance of parasite studies in biodiversity conservation. Its occurrence in a preserved area like the PNI emphasises the role of such habitats in maintaining unique ecological interactions.

Este estudio proporciona una redescripción morfológica integral de Mastophorus muris Gmelin, 1790, un nematodo del orden Spirurida, basada en especímenes recolectados de Rattus norvegicus Berkenhout, 1769 en el municipio de Nova Iguaçu, Río de Janeiro, Brasil. Empleando microscopía óptica y electrónica de barrido, detallamos características morfológicas, incluidas características no reportadas previamente, como un par de papilas adcloacales y detalles de dientes del pseudolabio. Además, informamos de una nueva distribución geográfica para M. muris en Brasil. La baja prevalencia de M. muris observada en este estudio resalta el impacto potencial de los cambios antropogénicos en la distribución del parásito. Se necesitan investigaciones adicionales, incluidos análisis moleculares, para dilucidar la complejidad taxonómica y las relaciones huésped-parásito dentro del género Mastophorus.

An integrative taxonomic description of Aponurus laguncula (Lecithasteridae), a digenean parasitic species of Chaetodipterus faber (Acanthuriformes) from Brazilian Southeast, is provided. Morphological techniques, as whole mounted slides, histology and scanning electron microscopy, and molecular analyses supported that integrative description. Fifteen digenean specimens were stained in hydrochloric carmine and mounted on permanent slides. Two specimens were stained in hematoxylin and eosin following histological routine processing. Four parasites were dehydrated through a graded ethanol series, critical point dried with carbon dioxide and coated with gold to scanning electron microscopy analysis. Sequence of the large ribosomal subunit (28S rDNA) gene was generated and used to construct a phylogeny based on maximum likelihood and Bayesian inference analyses. Morphological description and morphometric data obtained in present study were in accordance with previous studies of the species. Use of another morphological techniques, as scanning electron microscopy and histology, corroborated the observed features of whole mounted slides. Also, they provided a better observation of previous reported characteristics and new features reporting, such as an elongated hermaphroditic duct, a smooth tegument and cells that compose the prostatic gland. The molecular sequence obtained in the present study formed a robust clade with available sequences of species of Aponurus. The integrative taxonomic approach successfully combined morphological observations, including both previously reported features and new descriptions from histological and electron microscopy analyses, with molecular data to identify these specimens as A. laguncula. Moreover, the detailed characterization of structures, such as the gonads in A. laguncula, that would be challenging to analyze using a single technique, was possible. Further molecular studies with less conserved genetic markers should be conducted to understand phylogenetic relationships between Aponurus species.

As part of a parasitological survey, several specimens of two new monopisthocotylean species, Neotetraonchus celsomanueli sp. nov. and N. peruvianus sp. nov. (Dactylogyridea, Dactylogyridae), were collected from the gill filaments of the Peruvian sea catfish Galeichthys peruvianus (Siluriformes, Ariidae) off Puerto Pizarro, Tumbes region, Peru. Neotetraonchus celsomanueli sp. nov. is characterised by an MCO with a T-shaped distal end and an accessory piece that is ribbed and expanded proximally with a worm-shaped termination. Neotetraonchus peruvianus sp. nov. is typified by its MCO, which has a sledgehammer-shaped distal end and an accessory piece with a claw-shaped distal end. Additionally, N. peruvianus sp. nov. is characterised by its jellyfish-shaped onchium. A partial 28S rDNA sequence was obtained from N. celsomanueli sp. nov., and a phylogenetic analysis was conducted. This analysis revealed the phylogenetic position of Neotetraonchus celsomanueli sp. nov. within a clade comprising monopisthocotylean parasites of diadromous and marine ariid catfishes, including Hamatopeduncularia spp., Chauhanellus spp., Thysanotohaptor Kritsky, Shameem, Kumari & Krishnaveni, 2012, and Neocalceostomoides spinivaginalis Lim, 1995. This finding brings the number of known Neotetraonchus species to seven and represents the first described Neotetraonchus species infecting marine catfishes from Peru.

The present work aims to expand the knowledge of the digenean species Prosogonotrema bilabiatum (Sclerodistomidae), a parasite of Chaetodipterus faber (Acanthuriformes) from Brazil, with an integrative taxonomic approach, using light microscopy, scanning electron microscopy, histology, and molecular biology. Forty-one digenean specimens were stained with hydrochloric carmine for morphological studies. Eleven parasites were dehydrated through a graded ethanol series, critical point dried with carbon dioxide, and coated with gold for scanning electron microscopy analysis. Four specimens were processed following histological routine and stained with hematoxylin and eosin and Gomori trichrome. DNA extracted was amplified using 28S partial primer D1–D3. Maximum likelihood and Bayesian inference were performed for phylogenetic analysis. Morphometric and morphological data of the specimens studied ranged in accordance as observed in previous descriptions of the species. Observations from scanning electron microscopy and histology corroborated with those observed in stained whole mounts. Molecular analysis showed that specimens of P. bilabiatum from Brazil clustered with another two sequences of this species from different hosts and localities, with a high node support value. The integrative taxonomic approach allowed to record and describe new characteristics of P. bilabiatum related to the tegument, the structure and the arrangement of its tissues. The use of molecular markers confirmed that specimens identified as P. bilabiatum from different hosts and localities are all conspecific. Further studies, mainly molecular with less conserved genetic markers, should be carried out to better understand the phylogenetic relationships of Prosogonotrema with Hemiuroidea.

A new species of nematode parasite of the genus Delicata (Molineidae: Anoplostrongylinae) is described from the small intestine of a road-killed Greater Naked-tailed Armadillo Cabassous tatouay (Cingulata: Chlamyphoridae) on the BR-040 highway in Rio de Janeiro state, Brazil. The genus Delicata includes 13 species of parasitizing armadillos and anteaters distributed in Brazil, Argentina, and Trinidad and Tobago. The present species is distinguished from almost all species of Delicata by the longest length of the body, except for D. khalili and D. appendiculata. However, these can be distinguished from each other by the length of the spicules. The species that closely resembles, Delicata tatouay n. sp. is D. speciosa, but it can be distinguished by a robust branch from rays 2 and 3, rays 4 larger, and rays 8 longer compared to those of the new species. The new species is the only one with a tail, characterized by a terminal spine with rattlesnake tail-like transversal striations.

Angiostrongylus cantonensis is a nematode parasite that resides in the pulmonary arteries of rodents, serving as its definitive hosts. The life cycle involves several species of non-marine gas-tropods as intermediate hosts, and the African giant snail Achatina fulica is considered one of the most important around the world. Experimental data concerning A. cantonensis infection in the African giant snail remains notably limited. This helminth causes eosinophilic meningitis or menin-goencephalitis in humans, representing an emergent zoonosis in Brazil. Understanding the host-parasite relationship through the application of new tools is crucial, given the complex interaction between zoonosis and the intricate mechanisms involving wild/human hosts, parasite adaptation, and dispersion. The objective of this study was to employ SEM as a novel methodology to understand the structural organization of the host tissue, particularly the granuloma formation. This sheds light on the complex balance between A. fulica and A. cantonensis. Nine three-month-old snails were randomly selected and exposed for 24 h to a concentration of 2000 L1/dose of A. cantonensis. A necropsy was performed 37 days after the infection, and the samples were examined using light and scanning electron microscopy (SEM). The histopathological results revealed third-stage larvae of A. cantonensis associated with granulomas distributed throughout the head-foot mass, mantle, and kidney. Scanning electron microscopy of the histological section surface showed that the granuloma is surrounded by a cluster of spherical particles, which are distributed in the region bordering the larvae. This reveal details of the nematode structure, demonstrating how this methodology can enhance our understanding of the role of granulomas in molluscan tissue. The structural characteristics of granuloma formation in A. fulica suggest it as an excellent invertebrate host for A. cantonensis. This relationship appears to provide protection to the parasite against the host's immune defense system while isolating the snail's tissue from potential exposure to nematode antigens.

Based on morphological and molecular data, Brotulella n. gen. is proposed to accommodate the dactylogyrid monogeneans Brotulella laurafernandae n. sp. (type species) and Brotulella luisahelenae n. sp. on the gill filaments of the Pacific bearded brotula Brotula clarkae Hubbs, 1944 (Ophidiiformes: Ophidiidae) from Puerto Pizarro in the Tumbes region (northern Peru). Species of the new genus are distinguished from all other dactylogyrids by the combination of the following features: (1) anchors with a stocking-shaped sheath associated with the distal end of superficial and deep roots, (2) tandem gonads, (3) a vas deferens looping left intestinal caecum, (4) a distally twisted male copulatory organ (MCO) with a delicate membranous accessory piece articulated to the shaft of the MCO, (5) a U-shaped ovary, (6) an almost sigmoid seminal vesicle, and (7) two prostatic reservoirs with thick muscular walls. A 28S ribosomal DNA-based phylogenetic analysis (Maximum likelihood and Bayesian inference) of sequences of two new species of Brotulella n. gen. from the Southeastern Pacific Ocean, along with sequences from closely related genera of the marine Dactylogyridae, supports the establishment of the new genus for the dactylogyrid parasites on the gills of the Pacific bearded brotula.

The nematode Angiostrongylus cantonensis has been reported worldwide. However, some basic questions remain unanswered about A. cantonensis in Ecuador: (1) Was the invasion of A. cantonensis in Ecuador unique, or did it occur in different waves? (2) Was this invasion as recent as historical records suggest? (3) Did this invasion come from other regions of South America or elsewhere? To address these issues, we assessed the genetic diversity of MT-CO1 gene sequences from isolates obtained in 11 of Ecuador’s 24 provinces. Our Bayesian inference phylogenetic tree recovered A. cantonensis as a well-supported monophyletic group. All 11 sequences from Ecuador were identical and identified as AC17a. The haplotype AC17a, found in Ecuador and the USA, formed a cluster with AC17b (USA), AC13 (Thailand), and AC12a-b (Cambodia). Notably, all the samples obtained in Ecuadorian provinces’ different geographic and climatic regions had no genetic difference. Despite the lack of genetic information on A. cantonensis in Latin America, except in Brazil, our finding differs from previous studies by its absence of gene diversity in Ecuador. We concluded that the invasion of A. cantonensis in Ecuador may have occurred: (1) as a one-time event, (2) recently, and (3) from Asia via the USA. Further research should include samples from countries neighboring Ecuador to delve deeper into this.

Citation: dos Santos, M.M.; Simões, R.d.O.; D'Andrea, P.S.; Verde, R.d.S.; Maldonado Júnior, A.; Argueta Cartagena, R.I.; Ubiali, D.G.; Luque, J.L. A New Species of Vampirolepis (Cestoda: Cyclophyllidea: Hymenolepididae) from the Bat Artibeus lituratus (Chiroptera: Phyllostomidae) in the Amazon Rainforest, Brazil. Diversity 2023, 15, 791. https://doi.org/10.3390/ d15060791 Academic Editors: Alexander B. Ruchin, Igor V. Chikhlyaev and Christoph Meyer Abstract: The Amazon biome has a great diversity of bat species. In the state of Acre, Brazil, there is an estimated occurrence of 64 bat species with the species of the genus Artibeus as one of the most abundant. Despite their abundance and widespread distribution within the biome, the helminth fauna from Amazonian bats is still poorly known. In this way, the objective of this study is to describe a new species of cestode from the genus Vampirolepis found in A. lituratus, collected at the Parque Estadual do Chandless, a natural preserved area, located in the Purus River Basin, Southwest Amazon, the state of Acre. The new species of Vampirolepis is distinguished from the others by the number and size of hooks, testes disposition, size of the cirrus sac, ovaries and internal and external seminal vesicles. Additionally, molecular study showed that this forms a paraphyletic clade with Vampirolepis elongatus.