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International Journal For Parasitology.... Aug 2023The preservation of the world's biodiversity for future generations has been a global objective for many years, with the establishment of the International Union for...
The preservation of the world's biodiversity for future generations has been a global objective for many years, with the establishment of the International Union for Conservation of Nature (IUCN) Red List of Threatened Species in 1964. However, the conservation of parasites is a more recent development and, due to the difficulty in obtaining data and studying some of the parasitic species, comes its own series of challenges. Using parasites of cyprinid hosts (one critically endangered, one endangered and three near threatened) collected from South Africa's Cape Fold freshwater ecoregion (CF) as a case study, this paper discusses the challenges and possible solutions for implementing a fish parasite conservation project. Novel data on the fish parasites (1819 metazoan parasite individuals, representing the Acanthocephala, Cestoda, Copepoda, Digenea, Monogenea and Nematoda) of the CF are provided from the five endemic hosts, (Peters, 1864), (Gilchrist et Thompson, 1913), (Barnard, 1938), (Barnard, 1938), and (Skelton, 1974). Conservation statuses for selected parasite taxa are also proposed based on the conservation statuses of the fish hosts, according to the Conservation Assessment Methodology for Animal Parasites (CAMAP).
PubMed: 37533698
DOI: 10.1016/j.ijppaw.2023.07.003 -
Scientific Reports Jun 2022Although parasite infection and pollution are common threats facing wild populations, the response of the gut microbiota to the joint impact of these stressors remains...
Although parasite infection and pollution are common threats facing wild populations, the response of the gut microbiota to the joint impact of these stressors remains largely understudied. Here, we experimentally investigated the effects of exposure to Polycyclic Aromatic Hydrocarbons (PAHs) and infection by a common acanthocephalan intestinal parasite (Pomphorhynchus sp.) on the gut microbial flora of a freshwater fish, the European chub (Squalius cephalus). Naturally infected or uninfected individuals were exposed to PAHs at environmentally realistic concentrations over a five-week period. Characterization of the gut bacterial community through 16S rRNA gene amplicon sequencing revealed that parasitic infection was a more structuring factor of bacterial diversity and composition than PAH exposure. Specifically, chub infected by Pomphorhynchus sp. harbored significantly less evenly represented gut bacterial communities than the uninfected ones. In addition, substantial changes in sequence abundance were observed within the main bacterial phyla, including the Firmicutes, Fusobacteriota, Actinobacteriota, and Proteobacteria. Again, these compositional changes correlated with host infection with Pomphorhynchus sp., confirming its pivotal role in gut microbial assemblage. Overall, these results highlight the importance of defining the parasitic status of individuals when conducting microbial ecotoxicological analyses at the digestive tract level, as this should lead to better understanding of microbiota modulations and help to identify microbial markers specifically associated with chemicals.
Topics: Acanthocephala; Animals; Bacteria; Cyprinidae; Dysbiosis; Gastrointestinal Microbiome; Polycyclic Aromatic Hydrocarbons; RNA, Ribosomal, 16S
PubMed: 35773378
DOI: 10.1038/s41598-022-15010-2 -
Parasite (Paris, France) 2022Sebkha Imlili (Atlantic Sahara) is a salt flat with over 160 permanent holes of hypersaline water generated in the Holocene and inhabited by euryhaline organisms that...
Sebkha Imlili (Atlantic Sahara) is a salt flat with over 160 permanent holes of hypersaline water generated in the Holocene and inhabited by euryhaline organisms that are considered to be relics of the past, including the cichlid fish Coptodon guineensis. We surveyed the fish parasites four times over one year, to i) identify the parasites, and ii) determine possible seasonality in infection patterns. Over 60% of the fish were infected by one to three helminths: an acanthocephalan in the intestine and two digenean metacercariae in the kidney, spleen, liver, muscle, and mesenteries. The acanthocephalan Acanthogyrus (Acanthosentis) cf. tilapiae was identified morphologically and molecularly; only one digenean (the heterophyid Pygidiopsis genata) could be identified molecularly. Both identified parasites were present throughout the sampling periods; the unidentified metacercariae were present only in summer and fall. Mean intensities, but not prevalence of infection by the acanthocephalan, reflected a biannual pattern of transmission. Infection accrued with fish size, possibly due to cannibalism. Because the water holes include only a few invertebrates, the intermediate hosts of these parasites can be inferred to be the gastropod Ecrobia ventrosa for the digeneans and either the copepod Cletocamtpus retrogressus or the ostracod Cyprideis torosa for the acanthocephalan. This ecosystem appears stable and provides a window into the past, as the acanthocephalan likely switched from freshwater tilapia to C. guineensis when the Sebkha formed. However, this is a vulnerable environment where the survival of these parasites depends on interactions maintained among only very few hosts.
Topics: Animals; Cichlids; Parasites; Ecosystem; Acanthocephala; Water; Metacercariae; Fish Diseases
PubMed: 36562431
DOI: 10.1051/parasite/2022064 -
Parasitology Dec 2020Acanthocephalans are parasites with complex lifecycles that are important components of aquatic systems and are often model species for parasite-mediated host...
Acanthocephalans are parasites with complex lifecycles that are important components of aquatic systems and are often model species for parasite-mediated host manipulation. Genetic characterization has recently resurrected Pomphorhynchus tereticollis as a distinct species from Pomphorhynchus laevis, with potential implications for fisheries management and host manipulation research. Morphological and molecular examinations of parasites from 7 English rivers across 9 fish species revealed that P. tereticollis was the only Pomphorhynchus parasite present in Britain, rather than P. laevis as previously recorded. Molecular analyses included two non-overlapping regions of the mitochondrial gene - cytochrome oxidase and generated 62 sequences for the shorter fragment (295 bp) and 74 for the larger fragment (583 bp). These were combined with 61 and 13 sequences respectively, from Genbank. A phylogenetic analysis using the two genetic regions and all the DNA sequences available for P. tereticollis identified two distinct genetic lineages in Britain. One lineage, possibly associated with cold water tolerant fish, potentially spread to the northern parts of Britain from the Baltic region via a northern route across the estuarine area of what is now the North Sea during the last Glaciation. The other lineage, associated with temperate freshwater fish, may have arrived later via the Rhine/Thames fluvial connection during the last glaciation or early Holocene when sea levels were low. These results raise important questions on this generalist parasite and its variously environmentally adapted hosts, and especially in relation to the consequences for parasite vicariance.
Topics: Acanthocephala; Animal Distribution; Animals; Climate; England; Fishes; Helminth Proteins; Host-Parasite Interactions; Larva; Phylogeny; Rivers; Salt Tolerance
PubMed: 32907651
DOI: 10.1017/S0031182020001663 -
Parasitology Research Jan 2022Macracanthorhynchus hirudinaceus is a zoonotic parasite affecting suids worldwide which are the definitive hosts for this helminth species. Macracanthorhynchus...
Macracanthorhynchus hirudinaceus is a zoonotic parasite affecting suids worldwide which are the definitive hosts for this helminth species. Macracanthorhynchus hirudinaceus is of significant economic and management concern due to its pathogenicity, causing intestinal obstruction and perforation in the definitive hosts. Current study is the preliminary investigation from Sardinia, Italy, reporting the pathomorphological findings and molecular characterization of M. hirudinaceus in the wild boars (Sus scrofa meridionalis). A total of 59 wild boars were examined showing acanthocephalan infection in 8 (13.6%) animals. In total, 49 parasites were collected with a mean intensity of 6.1. Comparatively higher infection levels were observed for males (16.7%) and young boars (14.3%); however, these epidemiological differences were statistically non-significant. Histopathological examination revealed the presence of a variable number of nodules (∼5 mm) in the intestine of M. hirudinaceus infested animals surrounded by a hyperemic-hemorrhagic halo. Several parasites were recovered from the intestinal lumen attached by the means of characteristic hooks showing necrosis in muscle layers. A moderate number of plump reactive fibroblasts and lesser numbers of fibrocytes were embedded with and at the borders of the inflammatory nodules in a moderate amount of homogeneous intensely eosinophilic fibrillary material rupturing the cell membrane. For molecular characterization, six isolated worms were amplified for the partial mitochondrial cox1 gene showing distinct interindividual variations. This first pathological and molecular description from southern Europe provided new knowledge about the diffusion of M. hirudinaceus in wild boars, furthering the research into the origin and transmission status of M. hirudinaceus in endemic localities.
Topics: Acanthocephala; Animals; Helminthiasis, Animal; Intestines; Male; Sus scrofa; Swine; Swine Diseases
PubMed: 34820718
DOI: 10.1007/s00436-021-07386-3 -
BMC Genomics Mar 2023Acanthocephala is a clade of obligate endoparasites whose mitochondrial genomes (mitogenomes) and evolution remain relatively poorly understood. Previous studies...
BACKGROUND
Acanthocephala is a clade of obligate endoparasites whose mitochondrial genomes (mitogenomes) and evolution remain relatively poorly understood. Previous studies reported that atp8 is lacking from acanthocephalan mitogenomes, and that tRNA genes often have nonstandard structures. Heterosentis pseudobagri (Arhythmacanthidae) is an acanthocephalan fish endoparasite for which no molecular data are currently available, and biological information is unavailable in the English language. Furthermore, there are currently no mitogenomes available for Arhythmacanthidae.
METHODS
We sequenced its mitogenome and transcriptome, and conducted comparative mitogenomic analyses with almost all available acanthocephalan mitogenomes.
RESULTS
The mitogenome had all genes encoded on the same strand and unique gene order in the dataset. Among the 12 protein-coding genes, several genes were highly divergent and annotated with difficulty. Moreover, several tRNA genes could not be identified automatically, so we had to identify them manually via a detailed comparison with orthologues. As common in acanthocephalans, some tRNAs lacked either the TWC arm or the DHU arm, but in several cases, we annotated tRNA genes only on the basis of the conserved narrow central segment comprising the anticodon, while the flanking 5' and 3' ends did not exhibit any resemblance to orthologues and they could not be folded into a tRNA secondary structure. We corroborated that these are not sequencing artefacts by assembling the mitogenome from transcriptomic data. Although this phenomenon was not observed in previous studies, our comparative analyses revealed the existence of highly divergent tRNAs in multiple acanthocephalan lineages.
CONCLUSIONS
These findings indicate either that multiple tRNA genes are non-functional or that (some) tRNA genes in (some) acanthocephalans might undergo extensive posttranscriptional tRNA processing which restores them to more conventional structures. It is necessary to sequence mitogenomes from yet unrepresented lineages and further explore the unusual patterns of tRNA evolution in Acanthocephala.
Topics: Animals; Acanthocephala; Genome, Mitochondrial; RNA, Transfer; Anticodon; Artifacts
PubMed: 36864372
DOI: 10.1186/s12864-023-09177-9 -
Systematic Parasitology Dec 2023Species of genus Polymorphus Lühe, 1911 (Polymorphidae) are acanthocephalans found in fish-eating birds and waterfowl. Although found in many parts of the world,...
Description and molecular data for a new acanthocephalan parasite, Polymorphus circi n. sp. (Polymorphidae) from the Australasian harrier (Circus approximans Peale) in New Zealand.
Species of genus Polymorphus Lühe, 1911 (Polymorphidae) are acanthocephalans found in fish-eating birds and waterfowl. Although found in many parts of the world, including Australia, no records exist from New Zealand. Because of the largely aquatic intermediate host, Polymorphus species are rarely found in terrestrial birds of prey. During a study of the helminths of the Australasian harrier Circus approximans Peale specimens of Polymorphus were recovered that were found to be new to science. Polymorphus circi n. sp. is formally described and genetic sequence data presented. Specimens were distinguished from all other species by a combination of characters, including their proboscis hook arrangement (20-22 rows of 11-13 hooks), as well as absence of sexual dimorphism, trunk size, proboscis shape and egg size. These acanthocephalans were found in birds from areas with the potential to support freshwater, brackish or marine amphipods, but as yet the actual intermediate hosts are unknown.
Topics: Animals; Parasites; New Zealand; Species Specificity; Acanthocephala; Birds
PubMed: 37874424
DOI: 10.1007/s11230-023-10120-5 -
Scientific Reports Oct 2021Nemertean worms belonging to the genus Carcinonemertes have been tied to the collapse of crab fisheries in the northeastern Pacific Ocean. A new species is described...
Nemertean worms belonging to the genus Carcinonemertes have been tied to the collapse of crab fisheries in the northeastern Pacific Ocean. A new species is described from egg masses of two commercial crabs, Cancer porteri and Romaleon setosum, inhabiting the central-north Chilean coast. This is the first species of Carcinonemertes described from the southeastern Pacific Ocean. Total body length of Carcinonemertes camanchaco sp. nov. ranged from 2.38 to 4.93 and from 4.29 to 8.92 mm, in males and females, respectively. Among others, traits that distinguish this new species from other previously described congeneric species include: presence of two gonad rows on each side of the intestine, a simple (not decorated) mucus sheath, and a relatively wide stylet basis. Maximum likelihood and Bayesian inference phylogenetic analyses distinguished this new species from all other species of Carcinonemertes with available cox1 sequences in GenBank. Prevalence and mean (± SD) intensity of C. camanchaco sp. nov. was 24% and 2.6 (± 2.07) worms per egg mass in C. porteri and 38.1% and 3.8 (± 2.4) worms per egg mass in R. setosum. The formal description of this new species represents the first step towards the understanding of this worm's impact on the health of crab fisheries in the southeastern Pacific Ocean.
Topics: Acanthocephala; Animals; Bayes Theorem; Body Size; Brachyura; Chile; DNA, Helminth; Female; Likelihood Functions; Male; Pacific Ocean; Phylogeny; Sequence Analysis, DNA
PubMed: 34642343
DOI: 10.1038/s41598-021-98650-0 -
Revista Brasileira de Parasitologia... 2020Specimens of Oncicola venezuelensis (Marteau, 1977) were recovered from fragments of intestinal tissue of a female Puma concolar (Linn, 1771) found dead in Petrópolis,...
Specimens of Oncicola venezuelensis (Marteau, 1977) were recovered from fragments of intestinal tissue of a female Puma concolar (Linn, 1771) found dead in Petrópolis, Rio de Janeiro in 2017. A total of 140 helminths were recovered. Five males and 5 females of the helminths were analyzed morphologically as well as 50 parasite eggs recovered in intestinal contents. Morphologically, these helminths were compatible with the genus Oncicola, because of the size and shape of the proboscis, the size and disposition of the lemnisci and the morphometry of the eggs, in which the external membrane of the shell was delicate and clear. From histopathology, the helminths were deeply embeded in the mucosa reaching up to the muscle layer. One specimen was also identified molecularly with universal primers that amplified the eukaryote region ITS1-5.8S-ITS2. The helminth showed 99% identity with the gene sequence of O. venezuelensis deposited in GenBank. It is important to emphasize, this parasite has been very little reported in the literature, which reinforces the importance of this report.
Topics: Acanthocephala; Animals; Brazil; DNA, Helminth; Female; Male; Puma
PubMed: 32667498
DOI: 10.1590/s1984-29612020046 -
Iranian Journal of Veterinary Research 2020is a parasite from the Acanthocephala phylum with worldwide distribution. parasites are found in pinnipeds as their definitive host.
BACKGROUND
is a parasite from the Acanthocephala phylum with worldwide distribution. parasites are found in pinnipeds as their definitive host.
AIMS
This study aimed to investigate the morphological and molecular characteristics of , and its histopathological effect on the intestinal tissue of .
METHODS
A severe infection was observed in the small intestine of a juvenile male Caspian seal (). The morphological descriptions were done using light microscopy, and scanning electron microscopy (SEM). The molecular diagnosis was performed using partial sequences of internal transcribed spacer 1 (ITS1) and 5.8S ribosomal RNA () gene.
RESULTS
According to the results, the specimens were identified as The histopathological inspection of intestinal tissue revealed lesions in epithelial cells, mucosa, submucosa and muscle layers, destruction of intestinal glands, and infiltration of inflammatory cells.
CONCLUSION
Presence of such a severe infection in one of the individual Caspian seals can suggest the possibility of morbidity among other seals in the landlocked Caspian Sea. Thus, further research on their parasite infections is required for understating the status of the Caspian seal population and conserving this endangered species.
PubMed: 33584844
DOI: No ID Found