RESUMO
OBJECTIVES: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.
Assuntos
Doenças dos Peixes , Microscopia Eletrônica de Varredura , Filogenia , Trematódeos , Infecções por Trematódeos , Animais , Brasil , Doenças dos Peixes/parasitologia , Trematódeos/genética , Trematódeos/classificação , Trematódeos/isolamento & purificação , Trematódeos/ultraestrutura , Trematódeos/anatomia & histologia , Microscopia Eletrônica de Varredura/veterinária , Infecções por Trematódeos/veterinária , Infecções por Trematódeos/parasitologia , RNA Ribossômico 28S/genética , Peixes/parasitologia , DNA Ribossômico/genética , DNA de Helmintos/genéticaRESUMO
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, , 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.
Assuntos
Peixes-Gato , Doenças dos Peixes , Brânquias , Filogenia , Animais , Peixes-Gato/parasitologia , Peru , Doenças dos Peixes/parasitologia , Brânquias/parasitologia , Infecções por Trematódeos/veterinária , Infecções por Trematódeos/parasitologia , DNA Ribossômico/genética , Trematódeos/classificação , Trematódeos/genética , Trematódeos/anatomia & histologia , Trematódeos/isolamento & purificação , DNA de Helmintos/genética , RNA Ribossômico 28S/genética , Platelmintos/classificação , Platelmintos/genética , Platelmintos/anatomia & histologia , Platelmintos/isolamento & purificação , Análise de Sequência de DNARESUMO
OBJECTIVES: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.
Assuntos
Doenças dos Peixes , Microscopia Eletrônica de Varredura , Filogenia , Trematódeos , Infecções por Trematódeos , Animais , Brasil/epidemiologia , Doenças dos Peixes/parasitologia , Trematódeos/classificação , Trematódeos/genética , Trematódeos/ultraestrutura , Trematódeos/anatomia & histologia , Trematódeos/isolamento & purificação , Microscopia Eletrônica de Varredura/veterinária , Infecções por Trematódeos/parasitologia , Infecções por Trematódeos/veterinária , Infecções por Trematódeos/epidemiologia , Peixes/parasitologia , DNA de Helmintos/genética , RNA Ribossômico 28S/genéticaRESUMO
The present paper describes a new species of Dermadena (Digenea) parasitizing Pseudobalistes naufragium in Puerto Pizarro, northern Peru, using light and scanning electronic microscopy (SEM). Additionally, molecular analysis was also performed to determine the phylogenetic affinities of Dermadena within the Lepocreadiidae. The new species is differentiated from Dermadena spatiosa, Dermadena stirlingi and Dermadena lactophrysi by presenting a curved and well-developed external seminal vesicle. Also, SEM revealed numerous dome-shaped tegument protuberances forming glandular papillae with transversal wrinkles arranged roughly in concentric rows around the acetabular region, varying in size from large at the middle of the body to small at the margin. In the molecular phylogeny, the new species formed a well-supported clade with sequences of species from the Lepocreadiidae, confirming that it belongs to this family.
Assuntos
Tetraodontiformes , Trematódeos , Infecções por Trematódeos , Animais , Oceano Pacífico , Filogenia , América do Sul , Trematódeos/genética , Infecções por Trematódeos/veterináriaRESUMO
An annotated checklist of the helminth parasites associated with reptiles from Peru is provided, as the result of a compilation of parasitological papers published between 1963 and January 2022 and records of species deposited in national and international collections. The list provides data on hosts, developmental stage, sites of infection, geographical distribution in Peruvian territory, code of material deposited in helminthological collections, references and taxonomic notes. The database includes records of 106 different species of helminth parasites (82 nominal species and 24 taxa identified at the generic level), the majority in the adult stage. These helminth parasites come from 18 of the 25 official Peruvian regions. Nematodes have the highest richness in number of species (79 species), followed by trematodes (17 species) and cestodes (nine species). The acanthocephalans are represented by only one species. The parasites with the highest number of records were Physaloptera retusa Rudolphi, 1819 (11 hosts), Physalopteroides venancioi (Lent, Freitas & Proença, 1946) (nine hosts), Strongyluris oscari Travassos, 1923 (seven hosts), and Parapharyngodon scleratus Travassos, 1923 (five hosts), all of which are nematodes. The 106 taxa of helminth parasites have been reported infecting 55 species of reptiles in Peru, distributed in 34 genera and 14 families. The reptile species harbouring the highest number of helminth parasites are the yellow-footed tortoise Chelonoidis denticulatus (Linnaeus) with 18 species (three trematodes and 15 nematodes), followed by the Peru desert tegu Dicrodon guttulatum Duméril & Bibron (Teiidae) with 11 species (three cestodes and eight nematodes) and the yellow-spotted Amazon River turtle Podocnemis unifilis Troschel (Podocnemididae) with 10 species (five trematodes and five nematodes). Of the 524 species of reptiles reported in Peru, only 55 (>10%) are reported as hosts of helminths representing a small proportion considering the great variety of reptile hosts that inhabit the various tropical and subtropical geographical areas of Peru.
Assuntos
Cestoides , Infecções por Cestoides , Helmintos , Parasitos , Tartarugas , Animais , Lista de Checagem , Humanos , Peru , Répteis/parasitologia , VertebradosRESUMO
Nematode species of the genus Contracaecum Railliet & Henry, 1912 have been reported around the world in many species of fish-eating birds and seals. Here, Contracaecum jorgei n. sp. is morphologically described using light and scanning electron microscopy for adults and fourth-stage larvae (L4) found in the bird Nannopterum brasilianus and third-stage larvae (L3) found in the freshwater fish Hoplias argentinensis, both from the province of Córdoba, Argentina. Additionally, sequences of cytochrome c oxidase subunit II were obtained from these specimens and molecular phylogenetic analysis was used to determine its relationships within the genus. The present species is distinguished from other species by the number and disposition of cephalic papillae; shape and size of the interlabia; length of the spicules; and number and arrangement of papillae in the posterior end of the male. Furthermore, in the molecular analyses, sequences obtained from adult L4 and L3 specimens of C. jorgei n. sp. were similar and grouped, forming an independent lineage, thus confirming it as a distinct species. Thus, morphological characteristics associated with molecular data support the proposal of a new species.
Assuntos
Anisaquíase/veterinária , Anisakis/anatomia & histologia , Anisakis/classificação , Aves/parasitologia , Caraciformes/parasitologia , Larva/classificação , Animais , Anisaquíase/epidemiologia , Anisakis/isolamento & purificação , Doenças das Aves/epidemiologia , Doenças das Aves/parasitologia , Feminino , Doenças dos Peixes/epidemiologia , Doenças dos Peixes/parasitologia , Água Doce , Larva/anatomia & histologia , Larva/ultraestrutura , Masculino , Microscopia , Microscopia Eletrônica de Varredura , FilogeniaRESUMO
Metazoan parasite assemblages of Pagrus pagrus inhabiting the southwestern Atlantic were analysed with the aim of identifying the existence of different stocks and to comparatively assess the value of different parasite guilds as indicators of zoogeographical regions. A total of 186 fish was examined. Samples were obtained from three Brazilian and one Argentine localities, distributed in three different biogeographic districts of the Argentine Zoogeographical Province. Pagrus pagrus harboured 26 metazoan parasite species distributed in three guilds, ectoparasites (10 species), long-lived larval endoparasites and short-lived gastrointestinal endoparasites (eight species each). Prevalence and abundance values of the former two guilds allowed analysing them comparatively to assess their value as biological indicators of both host population structure and zoogeography. Results of analyses on long-lived parasites evidenced the existence of three stocks, one in the regions of Rio de Janeiro and Sao Paulo, other in southern Brazil (Rio Grande do Sul) and a third in northern Argentina (Mar del Plata), responding to the differential environmental conditions characteristic of three zoogeographical ecoregions. Ectoparasite assemblages exhibited significant differences between all pairs of samples, including those considered as a single stock according to data on persistent parasites. Assemblages of long-lived larval parasites are considered as better indicators for stock assessment purposes than ectoparasites, whose population parameters were variable temporally and heterogeneous at small spatial scales. The distributional variability of persistent parasites of P. pagrus along large scales provides valuable information to help defining robust biogeographical patterns, applicable to stock identification and fishery management of this species.
Assuntos
Doenças dos Peixes/parasitologia , Parasitos/classificação , Parasitos/isolamento & purificação , Perciformes/parasitologia , Infecções Protozoárias em Animais/epidemiologia , Animais , Argentina/epidemiologia , Brasil/epidemiologia , Doenças dos Peixes/epidemiologia , Peixes , Infecções Protozoárias em Animais/parasitologiaRESUMO
Cystidicoloides vaucheri collected in the stomach of the redtail catfish Phractocephalus hemioliopterus from River Acre, State of Acre, Brazil is redescribed, including the first description of males and the first genetic characterization based upon 18S and 28S genes of the rRNA. Newly collected females were biometrically smaller than those reported in the original description, but similar morphology shared by the two samples revealed that they belong to the same species. Scanning electron micrographs showed the accurate structure of the cephalic region, described here in detail. Furthermore, the morphology of males completed the specific diagnosis, strengthening the validity of the species. The three other congeners differ from C. vaucheri mainly as follows: in C. dlouhyi the area rugosa is absent, the cephalic structures in C. fischeri are completely distinct, and in both species the spicules have membranous outgrowths, absent in C. vaucheri. Despite the dubious generic assignment of C. izecksohni, it differs from C. vaucheri in several biometrical and morphological features. Because of data availability, only sequences of the 18S were used for phylogenetic reconstructions. Results showed that the genus Ascarophis and the families Cystidicolidae and Physalopteridae are not monophyletic. Cystidicoloides vaucheri formed an independent branch clustering with representatives of Cystidicolidae, confirming its validity. The inclusion of Salmonema and Spinitectus within Cystidicolidae should be reviewed, since they formed an assemblage with species from Rhabdochonidae. In fact, current classification of some taxa belonging to Habronematoidea, Physalopteroidea and Thelazioidea need to be re-evaluated, mainly based on molecular data from different genes.