ABSTRACT
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.
Subject(s)
Acanthocephala , Anura , Helminthiasis, Animal , Animals , Acanthocephala/isolation & purification , Acanthocephala/physiology , Acanthocephala/classification , Brazil , Anura/parasitology , Helminthiasis, Animal/parasitology , Skin/parasitologyABSTRACT
The aim of this study was to record Centrorhynchus sp. associated with the exotic species Aquarana catesbeiana (bullfrog) in southern Brazil and to present a checklist of vertebrate hosts in South America. Twenty-nine adults and juveniles of A. catesbeiana were collected in Capão do Leão, state of Rio Grande do Sul, Brazil, between October 2019 and December 2020. We found 275 specimens of Centrorhynchus sp. cystacanths in the stomach musculature and coelomic cavity of 55.1% of hosts (16). There was no significant differences in the prevalence and mean intensity of infection with cystacanths when compared males and females of A. catesbeiana. The prevalence was significantly higher in adults than in juveniles. The checklist presents 106 species of vertebrate hosts and 14 taxa of Centrorhynchus recorded in nine South American countries. Avian were the main definitive hosts of Centrorhynchus spp. and snakes Dipsadidae, anurans Hylidae and Leptodactylidae the main paratenic hosts in South America. This is the first record of Centrorhynchus cystacanths in A. catesbeiana in the South America. The study provides tools to help understand the parasitic relationships between species of Centrorhynchus and A. catesbeiana and other hosts in areas where bullfrog have been introduced.
Subject(s)
Acanthocephala , Anura , Checklist , Animals , Anura/parasitology , Female , Male , Brazil , Acanthocephala/classification , Acanthocephala/isolation & purification , South America , Prevalence , Helminthiasis, Animal/parasitology , Helminthiasis, Animal/epidemiology , Vertebrates/parasitology , Birds/parasitology , Snakes/parasitologyABSTRACT
Metal(loid) bioaccumulation in acanthocephalans (Dentitruncus truttae) and intestines of fish (Salmo trutta) from the Krka River, influenced by industrial and municipal wastewaters, was investigated in relation to exposure to metal(loid)s from fish gut content (GC), water, and sediment to estimate potentially available metal (loid)s responsible for toxic effects and cellular disturbances in biota. Sampling was performed in two seasons (spring and autumn) at the reference site (river source, KRS), downstream of the wastewater outlets (Town of Knin, KRK), and in the national park (KNP). Metal(loid) concentrations were measured by ICP-MS. The highest accumulation of As, Ba, Ca, Cu, Fe, Pb, Se and Zn was observed mainly in organisms from KRK, of Cd, Cs, Rb and Tl at KRS, and of Hg, Mn, Mo, Sr and V at KNP. Acanthocephalans showed significantly higher bioaccumulation than fish intestine, especially of toxic metals (Pb, Cd and Tl). Metal(loid) bioaccumulation in organisms partially coincided to exposure from water, sediments and food, while in GC almost all elements were elevated at KNP, reflecting the metal(loid) exposure from sediments. Seasonal differences in organisms and GC indicated higher metal (loid) accumulation in spring, which follows enhanced fish feeding rates. Higher number of acanthocephalans in the intestine influenced biodilution process and lower concentrations of metal(loid)s in fish, indicating positive effects of parasites to their host, as supported by high values of bioconcentration factors. Fish intestine and acanthocephalan D. truttae were confirmed as sensitive indicators of available metal fraction in conditions of generally low environmental exposure in karst ecosystem. Since metal(loid) accumulation depended on ecological, chemical and biological conditions, but also on the dietary habits, physiology of organisms and parasite infection, continuous monitoring is recommended to distinguish between the effects of these factors and environmental exposure when assessing dietary associated metal(loid) exposure in aquatic organisms.
Subject(s)
Acanthocephala , Intestines , Water Pollutants, Chemical , Animals , Acanthocephala/metabolism , Water Pollutants, Chemical/metabolism , Water Pollutants, Chemical/analysis , Intestines/parasitology , Environmental Monitoring , Metals/metabolism , Fish Diseases/parasitology , Fish Diseases/metabolism , Rivers/chemistry , Fishes/metabolism , Wastewater/parasitology , Wastewater/chemistry , BioaccumulationABSTRACT
Knowledge of parasite-host interactions is essential for understanding factors associated with the ecology and evolution of both groups. Some aspects, such as host size and phylogeny, as well as parasite specificity, are significant predictors that help unveil the parasite-host relationship. Thus, the goals of this study were: (1) to describe parasite diversity in regions of the Atlantic Forest; (2) to analyze which host characteristics can influence parasite richness of anuran's parasite component community; and (3) to investigate if the prevalence of parasite infection is related to specificity metrics (ecological and phylogenetic), number of infected hosts and parasite's abundance. We identified 49 parasite taxa, classified into three phyla: Nematoda, Acanthocephala, and Platyhelminthes. Supporting the existing literature, our findings corroborate the positive relationship between host size and parasite richness, further emphasizing the significance of this predictor. Parasite prevalence in the host community is related to the number of infected host species and parasite abundance, but not to phylogenetic and ecological specificity indices. This shows that parasite prevalence is strongly associated with infection opportunity, host sampling effort, and high parasite abundance.
Subject(s)
Anura , Biodiversity , Forests , Host-Parasite Interactions , Nematoda , Phylogeny , Animals , Anura/parasitology , Nematoda/classification , Brazil/epidemiology , Acanthocephala/classification , Acanthocephala/physiology , Acanthocephala/isolation & purification , Prevalence , Helminths/classification , Helminths/isolation & purification , Helminths/genetics , Host SpecificityABSTRACT
We inventoried all nine species of the 'Acanthephyra purpurea' complex, one of the most abundant and cosmopolitan group of mesopelagic shrimps. We used 119 specimens at hand and genetic data for 124 specimens from GenBank and BOLD. Phylogenetic analysis of four genes (COI, 16S, NaK, and enolase) showed that the 'Acanthephyra purpurea' complex is polyphyletic and encompasses two species groups, 'A. purpurea' (mostly Atlantic) and 'A. smithi' (Indo-West Pacific). The 'A. purpurea' species group consists of two major molecular clades A. pelagica and A. kingsleyi - A. purpurea - A. quadrispinosa. Molecular data suggest that hitherto accepted species A. acanthitelsonis, A. pelagica, and A. sica should be considered as synonyms. The Atlantic is inhabited by at least two cryptic genetic lineages of A. pelagica and A. quadrispinosa. Morphological analyses of qualitative and quantitative (900 measurements) characters resulted in a tabular key to species and in a finding of four evolutionary traits. Atlantic species showed various scenarios of diversification visible on mitochondrial gene level, nuclear gene level, and morphological level. We recorded and discussed similar phylogeographic trends in diversification and in distribution of genetic lineages within two different clades: A. pelagica and A. kingsleyi - A. purpurea - A. quadrispinosa.
Subject(s)
Acanthocephala , Decapoda , Animals , Phylogeny , DNA, Mitochondrial/genetics , Phylogeography , Biological Evolution , Acanthocephala/geneticsABSTRACT
Acanthocephalans are a group of obligate endoparasites that alternate between vertebrates and invertebrates to complete their life cycles. Occasionally, the same individual host acts as a definitive or paratenic host for different acanthocephalan species. In this study, acanthocephalans were sampled in marine fish in three localities of the Yucatán Peninsula; adults and cystacanths were recovered from the intestine and body cavity, respectively, of Haemulon plumierii from off the coast of Sisal, Yucatán. Ribosomal DNA sequences (small and large subunits) were used to test the phylogenetic position of the species of the genus Dollfusentis, whereas the mtDNA gene cox 1 was used for assessing species delimitation. The cox 1 analysis revealed an independent genetic lineage, which is recognized herein as a new species, Dollfusentis mayae n. sp. The new species is morphologically distinguished from the other six congeners by having a cylindrical proboscis armed with 22-25 longitudinal rows bearing 12 hooks each. The cystacanths were morphologically identified as Gorgorhynchus medius by having a cylindrical trunk covered with tiny irregular spines on the anterior region, and a cylindrical proboscis armed with 17-18 longitudinal rows of 21 hooks each; small and large subunit phylogenetic analyses yielded G. medius within the family Isthomosacanthidae, suggesting that Gorgorhynchus should be transferred to this family from Rhadinorhynchidae where it is currently allocated.
Subject(s)
Acanthocephala , Helminthiasis, Animal , Perciformes , Animals , Mexico , Phylogeny , Helminthiasis, Animal/parasitology , Fishes/parasitology , Perciformes/parasitologyABSTRACT
A new species of Moniliformis, M. tupaia n. sp. is described using integrated morphological methods (light and scanning electron microscopy) and molecular techniques (sequencing and analysing the nuclear 18S, ITS, 28S regions and mitochondrial cox1 and cox2 genes), based on specimens collected from the intestine of the northern tree shrew Tupaia belangeri chinensis Anderson (Scandentia: Tupaiidae) in China. Phylogenetic analyses show that M. tupaia n. sp. is a sister to M. moniliformis in the genus Moniliformis, and also challenge the systematic status of Nephridiacanthus major. Moniliformis tupaia n. sp. represents the third Moniliformis species reported from China.
Subject(s)
Acanthocephala , Phylogeny , Tupaia , Animals , Tupaia/parasitology , Tupaia/genetics , China , Acanthocephala/genetics , Acanthocephala/classification , Acanthocephala/anatomy & histology , Acanthocephala/ultrastructure , Helminthiasis, Animal/parasitology , Microscopy, Electron, Scanning/veterinary , DNA, Helminth/genetics , RNA, Ribosomal, 18S/genetics , Female , Male , RNA, Ribosomal, 28S/genetics , Intestines/parasitologyABSTRACT
Acanthocephaliasis is a zoonotic parasitic infection of vertebrates. The phylum Acanthocephala contains nearly 1500 acanthocephalan species. The Archiacanthocephala class is observed in terrestrial habitats and usually has a large, spineless trunk. Acanthocephalans are parasitic worms that use insects as intermediate hosts in their two-host life cycles. Insects, millipedes, and crustaceans in terrestrial areas serve as intermediate hosts and birds and mammals as definitive hosts. Acanthocephalans collected from the red fox (Vulpes vulpes) found dead on the road to Sarikamis-Kars in 1995 and stored in formaldehyde were kept in Ondokuz Mays University Faculty of Veterinary Medicine, Veterinary Parasitology Laboratory Museum until 2023 after our parasitological study found an infected red fox with Pachysentis sp. This study provides the anatomy of the acanthocephalans and the laboratory practice necessary for a good and reliable diagnosis. This study reports a new species, Pachysentis sp., of acanthocephalan (thorny-headed worm) found in red foxes for Türkiye. On the basis of relevant articles, we have created a key to Acanthocephala species occurring in mammals.
Subject(s)
Acanthocephala , Arthropods , Humans , Animals , Foxes , Turkey , ZoonosesABSTRACT
In Brazil, acanthocephalans parasitise anurans in several biomes. In the present study, we performed an analysis of acanthocephalan infections across 175 anuran individuals from the Cerrado biome, belonging to ten species: Boana raniceps, Pithecopus hypochondrialis, Scinax fuscomarginatus, Scinax x-signatus, Leptodactylus pustulatus, Leptodactylus macrosternum, Leptodactylus vastus, Physalaemus cuvieri, Adenomera hylaedactyla, and Elachistocleis piauiensis. We also verified the specificity of the parasites using the STD* index. Additionally, we conducted a survey of acanthocephalan infection in anurans in South America. The studied assemblage in the Brazilian Cerrado presented 57 parasitised hosts of 175 specimens (overall prevalence: 32.6%). In total, 437 acanthocephalans cystacanths were recorded, among which 286 presented the same morphotype but could not be identified, 148 belonged to the genus Centrorhynchus, and three belonged to Oncicola. Unidentified acanthocephalans had a higher prevalence in L. vastus (53.85%) and the highest intensity was in L. pustulatus (17±16). The highest prevalence of Centrorhynchus sp. was in the species S. fuscomarginatus (28.57%), while the highest intensity was observed in L. vastus (111). The taxon Oncicola sp. it had a prevalence of 3.23% and an intensity of 3 only in S. x-signatus. The highest specificity was recorded for Oncicola sp. (STD*= 1), whereas the lowest was found in Centrorhynchus sp. (STD*= 2.21). Finally, according to the survey for South America, we found ten records of acanthocephalan taxa parasitizing 58 species of anurans distributed in seven countries (Brazil with the most records).
Subject(s)
Acanthocephala , Humans , Animals , Brazil/epidemiology , Anura/parasitology , Ecosystem , PrevalenceABSTRACT
Between 2010 and 2023, a longitudinal study was undertaken to uncover the diversity of the parasite fauna of marine fishes in the Cat Ba Archipelago, a world biosphere reserve, in Vietnam. A total of 1,042 specimens representing 80 different fish species were collected and examined. Of these, 68 fish species, represented by 994 specimens (95.39%), were infected with parasites. A total of 162 parasitic species were discovered, including 54 trematodes, 37 monogeneans, 27 crustaceans, 15 myxozoans, 10 acanthocephalans, 10 nematodes, 7 cestodes, and 2 hirudineans. Over the course of the survey, twenty new species were described, including 7 acanthocephalans and 13 trematodes. Additionally, twenty species were recorded for the first time from the Cat Ba Archipelago and twenty-two species had new host records reported. The prevalence and mean intensity of parasite infection were found to be unaffected by season. These data on the parasitic fauna of Cat Ba Archipelago not only expand our knowledge of the diversity of Vietnam, but also provide strong baseline data for measuring future change resulting from environmental perturbations.
Subject(s)
Acanthocephala , Fish Diseases , Parasites , Trematoda , Animals , Vietnam/epidemiology , Longitudinal Studies , Species Specificity , Fishes/parasitology , Fish Diseases/epidemiology , Fish Diseases/parasitologyABSTRACT
Neorhadinorhynchus nudus (Harada, 1938) Yamaguti, 1939 (Cavisomidae) was morphologically described from the frigate tuna Auxis thazard (Lacépède) (Scombridae) in Nha Trang, Pacific south Vietnam. Females of N. nudus were fully described for the first time in the Pacific. Its original inadequate description as Rhadinorhynchus nudus (Harada, 1938) was corrected in material from Fiji Island, the Red Sea and Pacific Vietnam and errors in the text and line drawings of Harada were repeated in subsequent major publications where it underwent considerable nomenclature changes. New descriptive and biogeographical notes are included. We also provided here the molecular characterization of the nuclear gene (18S) and the mitochondrial cytochrome c oxidase subunit 1 (cox1) sequence data of N. nudus. Furthermore, to elucidate the phylogenetic relationship of N. nudus within the family Cavisomidae and with other isolates were performed incorporating nuclear (18S) and mitochondrial (cox1) sequence data using maximum likelihood (ML) and Bayesian inference (BI). The phylogenetic results showed that N. nudus has a relationship with other isolates of the same species and the median-joining network showed the pattern of haplotypes that reflected the structure of the populations.
Subject(s)
Acanthocephala , Animals , Female , Acanthocephala/genetics , Bayes Theorem , Phylogeny , Vietnam , Species Specificity , FishesABSTRACT
Acanthocephalans are dioecious parasites that gain sexual maturity in the alimentary canal of their definitive hosts (gnathostome vertebrates). This initial survey by light and transmission electron microscopy was conducted on the functional organization of the ovarian balls and uterine bell in mature females and on Saefftigen's pouch and the copulatory bursa in males. We studied these structures via the example of Centrorhynchus globocaudatus (Palaeacanthocephala) in Falco tinnunculus and Buteo buteo, from the Province of Ferrara (Northern Italy). Our study confirms that the ovarian balls have surface microvilli and consist of a multinucleate supporting syncytium and a cellular region with oogonial syncytium, single germ cells, zygotes, and shelled eggs. Germ cells are embedded in the supporting syncytium. The ultrastructural features of these components and data on fertilization, shell formation, and release from the ovarian ball, alongside insights into the likely egg sorting function of the uterine bell, are provided. We also present light and electron microscopy observations of Saefftigen's pouch and a suggestion regarding its hydrostatic functioning in the eversion of the copulatory bursa.
Subject(s)
Acanthocephala , Parasites , Raptors , Animals , Female , Male , Acanthocephala/ultrastructure , Microscopy, Electron , Zygote , Raptors/parasitologyABSTRACT
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.
Subject(s)
Acanthocephala , Parasites , Animals , Anura , Bufonidae , Argentina , LarvaABSTRACT
The Australasian harrier Circus approximans, a native of Australia, New Zealand and the South Pacific, is an opportunistic hunter of small prey, although a large part of its diet consists of carrion, mainly from roadkill. Besides a record of a single, unnamed species of capillariid nematode there have been no investigations into the parasites of Australasian harriers in New Zealand. In this study, a helminthological survey of sixty-five deceased harriers from southern New Zealand uncovered a gastrointestinal helminth fauna consisting of six parasite species. Porrocaecum circinum (Nematoda) was previously described only from fragmented females, and a redescription is presented here. Procyrnea fraseri n. sp. (Nematoda) is described, and distinguished from its congeners by its slender body shape and shorter spicules. Strigea falconis (Trematoda) is reported for the first time in New Zealand. Cladotaenia anomalis (Cestoda) and Polymorphus circi (Acanthocephala) were previously described as new species elsewhere. An unnamed species of capillariid appears to be mainly confined to North Island and is rare in South Island. Prevalence and intensity metrics are given, and DNA sequences provided to accompany new re/descriptions. Potential intermediate hosts are discussed, and the origins of the helminths and their potential for pathogenicity are considered.
Subject(s)
Acanthocephala , Cestoda , Helminths , Nematoda , Spirurida , Trematoda , Female , Animals , New Zealand , Nematoda/genetics , Helminths/genetics , Birds/parasitologyABSTRACT
The acanthocephalan Moniliformis saudi Amin, Heckmann, Mohammed, Evans, 2016 was originally described from the desert hedgehog, Paraechinus aethiopicus (Ehrenberg) in central Saudi Arabia. The distribution of P. aethiopicus extends to North Africa and west to Mauritania. Moniliformis saudi was recently found in the Algerian hedgehog Atelerix algirus (Lereboullet) in Malta. The distribution of A. algirus is restricted to the North African and east Iberian Mediterranean coast and associated islands. Both host species cohabit and share the same feeding grounds in northern Algeria where common infections appear to take place. The morphology of specimens from both acanthocephalan populations was similar, with minor variations mostly related to the relatively larger Maltese specimens especially the trunk and the male reproductive system. Taxonomic features like the cone-shaped anterior trunk, size and formula of proboscis and hooks, the receptacle, size and shape of eggs, anatomy of the apical proboscis sensory pores, and the stellate body wall giant nuclei were, however, practically identical. SEM and microscope images of specimens of the Maltese population emphasize their qualitative characteristics such as the degree of the extreme spiral muscle development and the development of the posterior nucleated pouches of the proboscis receptacle. Proboscis hooks of specimens from both the Maltese and the Saudi populations had similarly high levels (percent weights) of calcium, moderate levels of phosphorus, and minimal levels of sulfur, magnesium and sodium marking the diagnostic value of the Energy Dispersive x-ray analysis in species recognition. Newly generated partial sequences of the 18S ribosomal RNA and cytochrome C oxidase subunit 1 (Cox1) of the mitochondrial gene were generated from M. saudi from Malta. Moniliformis saudi from Malta, when compared with other available sequences of the same species isolates available in the GenBank database, formed a strongly supported clade with other congeners. The comparison of the molecular profiles of specimens from populations in Malta, Spain, and Saudi Arabia shows no or low genetic variation between them. Ultimately, we provide a morphological and molecular description of a new population of M. saudi from a new host species in a new geographical location, vastly exceeding the originally described ones from Saudi Arabia. A Cox 1 haplotype network inferred with 10 sequences revealed the presence of eight haplotypes, one of which was shared between the populations of Malta and Spain of M. saudi.
Subject(s)
Acanthocephala , Moniliformis , Animals , Male , Acanthocephala/genetics , Hedgehogs , Malta , Saudi Arabia , Species SpecificityABSTRACT
Acanthocephalans of the order Polymorphida mainly parasitic in birds and mammals, are of veterinary, medical and economic importance. However, the evolutionary relationships of its 3 families (Centrorhynchidae, Polymorphidae and Plagiorhynchidae) remain under debate. Additionally, some species of Polymorphida (i.e. Bolbosoma spp. and Corynosoma spp.) are recognized as zoonotic parasites, associated with human acanthocephaliasis, but the mitochondrial genomes for representatives of Bolbosoma and Corynosoma have not been reported so far. In the present study, the complete mitochondrial genomes B. nipponicum and C. villosum (Acanthocephala: Polymorphidae) are reported for the first time, which are 14 296 and 14 241 bp in length, respectively, and both contain 36 genes [including 12 PCGs, 22 tRNA genes and 2 rRNA genes] and 2 non-coding regions (NCR1 and NCR2). The gene arrangement of some tRNAs in the mitogenomes of B. nipponicum and C. villosum differs from that found in all other acanthocephalans, except Polymorphus minutus. Phylogenetic results based on concatenated amino acid (AA) sequences of the 12 protein-coding genes (PCGs) strongly supported that the family Polymorphidae is a sister to the Centrorhynchidae rather than the Plagiorhynchidae, and also confirmed the sister relationship of the genera Bolbosoma and Corynosoma in the Polymorphidae based on the mitogenomic data for the first time. Our present findings further clarified the phylogenetic relationships of the 3 families Plagiorhynchidae, Centrorhynchidae and Polymorphidae, enriched the mitogenome data of the phylum Acanthocephala (especially the order Polymorphida), and provided the resource of genetic data for diagnosing these 2 pathogenic parasites of human acanthocephaliasis.
Subject(s)
Acanthocephala , Genome, Mitochondrial , Parasites , Animals , Humans , Acanthocephala/genetics , Phylogeny , Parasites/genetics , Birds , MammalsABSTRACT
PURPOSE: The aim of this article is to describe a new and unusual species of Neoechinoprhynchus Stiles & Hassall, 1905 from the Arabian Gulf coast off Iraq. METHODS: Routine methods for examination of fish hosts and recovery of acanthocephalean parasites were followed. Parasites were cleaned, relaxed overnight in refrigerated water then fixed in cold 70% ethanol. Standard procedure for staining, dehydration, clearing in xylene and mounting in Canada balsam was followed. RESULTS: Neoechinorhynchus miniovalis n. sp. is described from five whole-mounted specimens collected from the mudskipper Boleophthalmus dussumieri Valenciennes (Oxudericidae) captured in Shatt Al-Basrah Canal, Iraq in 2008. It is distinguished from other species of Neoechinorhynchus Stiles and Hassall, 1905 by a combination of the following diagnostic characters: very small ellipsoid trunk with tapering posterior end and correspondingly small size organs; body wall with similar thickness dorso-ventrally; proboscis wider than long with long anterior hooks having prominent roots; hooks in second and third circles much smaller and rootless; receptacle 5-6 times as long as proboscis with a triangular cephalic ganglion at its base; no para-receptacle structure; lemnisci relatively long and equal, not reaching anterior testis; all male reproductive structures contiguous in posterior two-thirds of trunk; testes equatorial and much wider than long; anterior testis smaller than posterior testis; large syncytial cement gland with six giant nuclei; cement reservoir adjacent to anterior end of sperm vesicle adjacent to Saefftigen's pouch. No sexual dimorphism except that the trunk is more rounded in females than in males. The female reproductive system is about one-third as long as the trunk with the selective apparatus in two positions and uterine bell angulating ventrad. Female lemnisci are longer than in males. Comparisons with worldwide and North American-related species that have partially similar features are made. CONCLUSIONS: The finding of Neoechinorhynchus miniovalis n. sp. with unusual small body and wide ellipsoid shape acanthocephalan is considered the first acanthocephalan species belonging to Neoechinorhynchus reported from Palearctic region compared to similar seven species reported only from Neotropical (three species), Nearctic regions (two species), far east (one species) and oriental (one species).
Subject(s)
Acanthocephala , Fish Diseases , Helminthiasis, Animal , Animals , Fish Diseases/parasitology , Helminthiasis, Animal/parasitology , Acanthocephala/classification , Acanthocephala/anatomy & histology , Acanthocephala/isolation & purification , Male , Iraq , Female , Perciformes/parasitologyABSTRACT
Our hypothesis for this study was that annual and seasonal variations do not influence the structure of the component communities and the diversity of metazoan parasites of spinycheek sleeper (Eleotris pisonis) in the Amazon River, state of Amapá, Brazil. A total of 164 fish were collected between 2020 and 2021, from which 888 parasites were found. In 2020, five species of parasites were found (one Nematoda, one Digenea, one Acanthocephala, one Arachnida and one Crustacea); and in 2021, five species were also found (three Nematoda, one Digenea and one Crustacea). Larvae of Contracaecum sp. were the dominant taxon throughout the study. The parasite species richness and Brillouin diversity index were higher in 2021, without significant differences between seasonal periods. Some component communities of parasites showed differences between years and between seasonal periods. These facts do not support the hypothesis that such variables would not influence the component communities of the parasites. Lastly, this report provides the first records of Spirocamallanus inopinatus, Genarchella genarchella, Acari, Ergasilus sp., Neoechinorhynchus sp., larvae of Pseudoproleptus sp. and larvae of Contracaecum sp. in E. pisonis.
Subject(s)
Acanthocephala , Ascaridoidea , Copepoda , Fish Diseases , Parasites , Perciformes , Trematoda , Animals , Seasons , Brazil , Rivers/parasitology , Larva , Fish Diseases/epidemiology , Fish Diseases/parasitologyABSTRACT
The Isthmosacanthidae acanthocephalan species of the genus Serrasentis are parasites of marine teleosts and an elasmobranch. In this study, Serrasentis gibsoni n. sp. is described from the intestines of four flatfish species (Paralichthyidae), namely Ancyclopsetta quadrocellata, Cyclopsetta chittendeni, Syacium gunteri, and S. papillosum from 10 oceanic sites in the Gulf of Mexico (GoM). Twenty sequences of the 'barcoding' region of cytochrome C oxidase subunit I gene were obtained from 20 adults of Serrasentis gibsoni n. sp. Additionally, five sequences of the barcoding region were obtained from five adults of rhadinorhynchid Gorgorhynchus lepidus from C. chittendeni, S. papillosum and one species of Haemulidae, Haemulom aurolineatum, from five oceanic sites from the GoM. Two phylogenetic approaches were followed: Bayesian inference and maximum likelihood. In both phylogenetic reconstructions, the sequences of Serrasentis gibsoni n. sp. were recovered as a monophyletic group within the genus Serrasentis and placed as a sister group to G. lepidus. However, due to the lack of molecular data for species of the Isthmosacanthidae and Rhadinorhynchidea, these phylogenetic inferences must be taken with caution. Serrasentis gibsoni n. sp. is the first species of Serrasentis described from Paralichthyidae flatfish species from marine waters of the Americas and from the GoM. Based on the barcoding data set analyzed, Serrasentis gibsoni n. sp. appears to have high intraspecific genetic variation; thus, it is necessary to continue exploring the genetic diversity of this species to infer its intraspecific evolutionary patterns.
Subject(s)
Acanthocephala , Flatfishes , Animals , Acanthocephala/genetics , Flatfishes/genetics , Flatfishes/parasitology , Phylogeny , Gulf of Mexico , Bayes Theorem , MexicoABSTRACT
Of the total 47 species in the subgenus Acanthosentis, 43 have been reported from the freshwater fishes of Asia. Amin et al. (2017) provided a key to the 23 species of the genus Acanthogyrus reported from the Indian subcontinent. The present study reports two new species: Acanthogyrus bispinosa n. sp. and A. garciai n. sp. from Cirrhinus mrigala Hamilton and Labeo calbasu Hamilton, respectively, and two previously described species: A. golvani Gupta and Jain, 1980 and A. hereterospinus Khan and Bilqees, 1990 from L. rohita Hamilton and L. catla Hamilton, respectively. A. bispinosa n. sp. comprises 3 circles of 6 proboscis hooks each. Trunk spines in A. bispinosa n. sp are divided into two groups: anterior and posterior separated by unarmed region, which has not been previously reported in the subgenus. Anterior spines are present in 7-8 and 7-10 circles in females and males, respectively, whereas posterior spines are in 23-28 and 31-38 circles in males and females, respectively. A. garciai n. sp. comprises 3 circles of 6-8 hooks each and a single set of trunk spines is present in A. garciai n. sp., comprising 35-42 and 25-45 circles in males and females, respectively. All four species were also characterised based on the 18S, 28S, and ITS1-5.8S-ITS2 rRNA molecular markers. The Bayesian inference tree generated based on these markers showed distinct identities of all the species, with a significant molecular divergence, ranging from 3.2 to 53.6%.