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Acta Parasitologica Mar 2022Studies of parasite communities and patterns in the Antarctic are an important knowledge base with the potential to track shifts in ecological relations and study the...
BACKGROUND
Studies of parasite communities and patterns in the Antarctic are an important knowledge base with the potential to track shifts in ecological relations and study the effects of climate change on host-parasite systems. Endemic Nototheniinae is the dominant fish group found in Antarctic marine habitats. Through their intermediate position within the food web, Nototheniinae link lower to higher trophic levels and thereby also form an important component of parasite life cycles. The study was set out to gain insight into the parasite fauna of Nototheniops larseni, N. nudifrons and Lepidonotothen squamifrons (Nototheniinae) from Elephant Island (Antarctica).
METHODS
Sampling was conducted at three locations around Elephant Island during the ANT-XXVIII/4 expedition of the research vessel Polarstern. The parasite fauna of three Nototheniine species was analysed, and findings were compared to previous parasitological and ecological research collated from a literature review.
RESULTS
All host species shared the parasites Neolebouria antarctica (Digenea), Corynosoma bullosum (Acanthocephala) and Pseudoterranova decipiens E (Nematoda). Other parasite taxa were exclusive to one host species in this study. Nototheniops nudifrons was infected by Ascarophis nototheniae (Nematoda), occasional infections of N. larseni with Echinorhynchus petrotschenkoi (Acanthocephala) and L. squamifrons with Elytrophalloides oatesi (Digenea) and larval tetraphyllidean Cestoda were detected.
CONCLUSION
All examined fish species' parasites were predominantly euryxenous regarding their fish hosts. The infection of Lepidonotothen squamifrons with Lepidapedon garrardi (Digenea) and Nototheniops larseni with Echinorhynchus petrotschenkoi represent new host records. Despite the challenges and limited opportunities for fishing in remote areas, future studies should continue sampling on a more regular basis and include a larger number of fish species and sampling sites within different habitats.
Topics: Animals; Antarctic Regions; Ascaridoidea; Fish Diseases; Host-Parasite Interactions; Parasites; Perciformes; Trematoda
PubMed: 34275092
DOI: 10.1007/s11686-021-00455-8 -
Parasite (Paris, France) 2023Although interest in Acanthocephala seems to have reached only a small community of researchers worldwide, we show in this opinion article that this group of parasites...
Although interest in Acanthocephala seems to have reached only a small community of researchers worldwide, we show in this opinion article that this group of parasites is composed of excellent model organisms for studying key questions in parasite molecular biology and cytogenetics, evolutionary ecology, and ecotoxicology. Their shared ancestry with free-living rotifers makes them an ideal group to explore the origins of the parasitic lifestyle and evolutionary drivers of host shifts and environmental transitions. They also provide useful features in the quest to decipher the proximate mechanisms of parasite-induced phenotypic alterations and better understand the evolution of behavioral manipulation. From an applied perspective, acanthocephalans' ability to accumulate contaminants offers useful opportunities to monitor the impacts - and evaluate the possible mitigation - of anthropogenic pollutants on aquatic fauna and develop the environmental parasitology framework. However, exploring these exciting research avenues will require connecting fragmentary knowledge by enlarging the taxonomic coverage of molecular and phenotypic data. In this opinion paper, we highlight the needs and opportunities of research on Acanthocephala in three main directions: (i) integrative taxonomy (including non-molecular tools) and phylogeny-based comparative analysis; (ii) ecology and evolution of life cycles, transmission strategies and host ranges; and (iii) environmental issues related to global changes, including ecotoxicology. In each section, the most promising ideas and developments are presented based on selected case studies, with the goal that the present and future generations of parasitologists further explore and increase knowledge of Acanthocephala.
Topics: Animals; Acanthocephala; Rotifera; Phylogeny; Parasites
PubMed: 37350678
DOI: 10.1051/parasite/2023026 -
Diseases of Aquatic Organisms Oct 2019Amphipods are commonly used test organisms in ecotoxicological studies. Nevertheless, their naturally occurring parasites have mostly been neglected in these... (Review)
Review
Amphipods are commonly used test organisms in ecotoxicological studies. Nevertheless, their naturally occurring parasites have mostly been neglected in these investigations, even though several groups of parasites can have a multitude of effects, e.g. on host survival, physiology, or behavior. In the present review, we summarize the knowledge on the effects of Microsporidia and Acanthocephala, 2 common and abundant groups of parasites in amphipods, on the outcome of ecotoxicological studies. Parasites can have significant effects on toxicological endpoints (e.g. mortality, biochemical markers) that are unexpected in some cases (e.g. down-regulation of heat shock protein 70 response in infected individuals). Therefore, parasites can bias the interpretation of results, for example if populations with different parasite profiles are compared, or if toxicological effects are masked by parasite effects. With the present review, we would like to encourage ecotoxicologists to consider parasites as an additional factor if field-collected test organisms are analyzed for biomarkers. Additionally, we suggest intensification of research activities on the effects of parasites in amphipods in connection with other stressors to disentangle parasite and pollution effects and to improve our understanding of parasite effects in this host taxon.
Topics: Acanthocephala; Amphipoda; Animals; Host-Parasite Interactions; Microsporidia; Parasites
PubMed: 31575839
DOI: 10.3354/dao03355 -
Current Research in Parasitology &... 2023Clearing infection is an essential step to address many issues in host-parasite interactions but is challenging when dealing with endoparasites of large size relative to...
Clearing infection is an essential step to address many issues in host-parasite interactions but is challenging when dealing with endoparasites of large size relative to that of their host. Here, we took advantage of the lethality, contactless and versatility of high-energy laser beam to achieve it, using thorny-headed worms (Acanthocephala) and their amphipod intermediate host as a model system. We show that laser-based de-parasitization can be achieved using 450 nm Blue Diode Laser targeting carotenoid pigments in the bird acanthocephalan . Using proboscis evagination failure and DNA degradation to establish parasite death, we found that 80% died from within-host exposure to 5 pulses of 50 ms duration, 1.4 W power. Survival of infected gammarids 11 days after laser treatment was 60%. Preliminary tests were also performed with Nanosecond-Green Laser targeting lipids in another acanthocephalan parasite. We discuss the efficiency and side-effect of laser treatment in this host-parasite system and highlight the perspectives that this technology more generally offers in parasitology.
PubMed: 37583436
DOI: 10.1016/j.crpvbd.2023.100135 -
Systematic Parasitology Oct 2023The acanthocephalan Macracanthorhynchus ingens (von Linstow 1879) (Acanthocephala: Archiacanthocephala) is a parasite that infects the gut of carnivores (racoons,...
A molecular and ecological study of Macracanthorhynchus ingens (von Linstow, 1879) (Acanthocephala: Archiacanthocephala), in its paratenic and definitive hosts in southeastern Mexico and the Eastern USA.
The acanthocephalan Macracanthorhynchus ingens (von Linstow 1879) (Acanthocephala: Archiacanthocephala) is a parasite that infects the gut of carnivores (racoons, coyotes, wolves, foxes, badgers, skunks, opossum, mink and bears) as an adult and the body cavity of lizards, snakes, and frogs as a cystacanth in the Americas. In this study, adults and cystacanths of M. ingens from southeastern Mexico and southern Florida, USA, were identified morphologically by having a cylindrical proboscis armed with 6 rows of hooks each with 6 hooks. Hologenophores were used to sequence the small (SSU) and large (LSU) subunits of ribosomal DNA and cytochrome c oxidase subunit 1 (cox 1) from mitochondrial DNA. Phylogenetic analysis of the new SSU and LSU sequences of M. ingens placed them in a clade with other sequences available in GenBank identified as M. ingens. The cox 1 tree showed that the nine new sequences and six previously published sequences of M. ingens from the USA form a clade with other sequences previously identified as M. ingens from GenBank. The intraspecific genetic divergence among isolates from the Americas ranged from 0 to 2%, and in combination with the phylogenetic trees confirmed that the isolates belonged to the same species. The cox 1 haplotype network inferred with 15 sequences revealed 10 haplotypes separated from each other by a few substitutions. Rio Grande Leopard Frogs and Vaillant´s Frogs harbored cystacanths with low prevalence, 28% and 37% respectively, in Mexico. Brown Basilisks, an invasive lizard in Florida, USA, had high values of prevalence, 92% and 93% in males and females, respectively. Females harbored more cystacanths than males (0-39 vs 0-21) for unknown reasons that may, however, be related to ecological differences.
Topics: Female; Male; Animals; Acanthocephala; Mexico; Phylogeny; Helminthiasis, Animal; Species Specificity
PubMed: 37338661
DOI: 10.1007/s11230-023-10104-5 -
Environmental Toxicology and Chemistry Sep 2023Parasites can affect their hosts in various ways, and this implies that parasites may act as additional biotic stressors in a multiple-stressor scenario, resembling...
Parasites can affect their hosts in various ways, and this implies that parasites may act as additional biotic stressors in a multiple-stressor scenario, resembling conditions often found in the field if, for example, pollutants and parasites occur simultaneously. Therefore, parasites represent important modulators of host reactions in ecotoxicological studies when measuring the response of organisms to stressors such as pollutants. In the present study, we introduce the most important groups of parasites occurring in organisms commonly used in ecotoxicological studies ranging from laboratory to field investigations. After briefly explaining their life cycles, we focus on parasite stages affecting selected ecotoxicologically relevant target species belonging to crustaceans, molluscs, and fish. We included ecotoxicological studies that consider the combination of effects of parasites and pollutants on the respective model organism with respect to aquatic host-parasite systems. We show that parasites from different taxonomic groups (e.g., Microsporidia, Monogenea, Trematoda, Cestoda, Acanthocephala, and Nematoda) clearly modulate the response to stressors in their hosts. The combined effects of environmental stressors and parasites can range from additive, antagonistic to synergistic. Our study points to potential drawbacks of ecotoxicological tests if parasite infections of test organisms, especially from the field, remain undetected and unaddressed. If these parasites are not detected and quantified, their physiological effects on the host cannot be separated from the ecotoxicological effects. This may render this type of ecotoxicological test erroneous. In laboratory tests, for example to determine effect or lethal concentrations, the presence of a parasite can also have a direct effect on the concentrations to be determined and thus on the subsequently determined security levels, such as predicted no-effect concentrations. Environ Toxicol Chem 2023;42:1946-1959. © 2023 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.
Topics: Animals; Parasites; Aquatic Organisms; Environmental Pollutants; Fishes; Nematoda; Water Pollutants, Chemical
PubMed: 37283208
DOI: 10.1002/etc.5689 -
Acta Parasitologica Jun 2022We aimed to describe the helminth fauna associated with two sympatric congeneric treefrogs species (Boana multifasciata and Boana raniceps) from a highland marsh in...
PURPOSE
We aimed to describe the helminth fauna associated with two sympatric congeneric treefrogs species (Boana multifasciata and Boana raniceps) from a highland marsh in northeastern Brazil. In addition, we investigate the body size influence on parasitological descriptors in these treefrogs, in which we expected that larger frogs would have greater abundance and richness helminths too, and no differences with respect to helminth composition once both hosts are exposed to similar environmental conditions.
METHODS
We collected anurans during the rainy season from 11 January to 09 February 2019, using visual and auditory searches in breeding environments. We analysed the presence of ectoparasites under an epidermis, oral cavity, and endoparasites present in the organs. Using a Linear mixed-effects model we tested the relationship between the host body size (length and weight) and helminths abundance and richness. In addition, we used the ANOSIM R test to investigate the differences between the hosts with respect to helminth composition.
RESULTS
We recorded 37 individuals (15 specimens of B. multifasciata and 22 of B. raniceps), in which 89.1% of them were infected by at least one helminth species. We found 355 helminths from 12 taxa parasitizing the two treefrogs, but just three parasite taxa were common to both species. All identified helminth species found in B. multifasciata are new records and four are new records for B. raniceps. In addition, we present the first record of Cosmocerca paraguayensis in Brazil. We found no support for the hypothesis that larger frogs tend to be more parasitized, at least for congeneric species, and sympatric hosts species have similar helminth composition. We also present a compilation of helminths occurring in treefrogs belonging to the Boana genus in South American, increasing our knowledge of the parasitic diversity of Neotropical anurans.
CONCLUSION
Our results suggest a lack of knowledge about helminth fauna associated with amphibians even for common and widely distributed species, such as Boana spp., and demonstrate the need to deepen our knowledge about host parasitic relationships, especially in the Neotropical region.
Topics: Animals; Anura; Brazil; Helminthiasis, Animal; Helminths; Wetlands
PubMed: 35000112
DOI: 10.1007/s11686-021-00497-y -
Acta Parasitologica Sep 2022Immature Southwellina hispida (Van Cleave, 1925) Witenberg, 1932 from the body cavity of the paratenic host Gillichthys mirabilis Cooper (Gobiidae) in California are...
Morphological and Molecular Description of Immature Southwellina hispida (Van Cleave, 1925) Witenberg, 1932 (Acanthocephala: Polymorphidae) from the Body Cavity of the Paratenic Host Gillichthys mirabilis Cooper (Gobiidae) in California, with Analyses of the Chemical Composition of Hooks and Spines.
PURPOSE
Immature Southwellina hispida (Van Cleave, 1925) Witenberg, 1932 from the body cavity of the paratenic host Gillichthys mirabilis Cooper (Gobiidae) in California are described.
METHODS
New Scanning Electron images and features of micropores, hook and spine Gallium cut sections and chemistry using Energy Dispersive X-ray analysis (EDXA), and molecular profile are provided for the first time. The 18S rDNA and mt Cox1 sequences were performed for molecular and phylogenetic study.
RESULTS
Our specimens were somewhat comparable to those reported from other paratenic hosts in Asia, Europe, and North and South America but varied in relative sizes of trunk and other structures, proboscis formula, and distribution of trunk spines. About 60 publications were reviewed of which one third included line drawings used for comparative morphometrics. In our specimens, the trunk measured 2.72-3.10 mm long by 0.92-1.07 mm wide and the proboscis 700-800 × 270-312 μm had 20-21 rows of 14-15 hooks each measuring 47-55 long by 12-15 μm wide at base anteriorly, 47-48 × 20-23 μm at middle bulge, and 43-50 × 13-20 μm basally. These measurements, among others were compared with measurements of juveniles from 13 other collections world-wide and intraspecific variability was noted especially in the shape of hook roots that were occasionally misinterpreted. EDXA showed hooks with high levels of Sulfur especially at the tip and edge of all hooks and low levels of Calcium and Phosphorus. Anterior spines had higher levels of Sodium but Gallium cut spine sections had higher levels of Calcium at middle and of Sulfur at base of spines. Micropores were variably distributed on the body wall and extended to the cortical layer of spines. Gene sequences of the 18S and the mitochondrial cytochrome c oxidase subunit 1 (cox 1) region were amplified for specimens of S. hispida. Molecular phylogenetic analysis inference from 18S rDNA and mt Cox1 gene sequences show a close relationship with previously reported myxozoan sequences available on GenBank database. Phylogenetic analysis positioned our S. hispida in a well-supported clade including other members of Polymorphidae.
CONCLUSION
The present study combined morphological, morphometric and molecular data to identify S. hispida.
Topics: Acanthocephala; Animals; Calcium; DNA, Ribosomal; Fish Diseases; Gallium; Helminthiasis, Animal; Microscopy, Electron, Scanning; Mirabilis; Perciformes; Phylogeny; Sulfur
PubMed: 35476262
DOI: 10.1007/s11686-022-00552-2 -
Parasitology Research Sep 2021The present paper describes Neoechinorhynchus (Neoechinorhynchus) cephali n. sp., an acanthocephalan parasite infecting the intestine of the flathead grey mullet Mugil...
Morphological and molecular characterization of Neoechinorhynchus (N.) cephali n. sp. (Acanthocephala: Neoechinorhynchidae) Stiles and Hassall 1905 infecting the flathead grey mullet Mugil cephalus (Linnaeus, 1758) from the southwest coast of India.
The present paper describes Neoechinorhynchus (Neoechinorhynchus) cephali n. sp., an acanthocephalan parasite infecting the intestine of the flathead grey mullet Mugil cephalus from the southwest coast of India. The parasite exhibited a prevalence of 7.40%, mean intensity of 18.5 and abundance of 18-19 worms/infected host. Morphologically, N. (N.) cephali n. sp. is sexually dimorphic, small, cylindrical, slightly curved and creamy white in colour. Females are larger than males, measured 8.87 × 0.88 mm and 5.65 × 0.66 mm, respectively. Proboscis is armed with three circles of six hooks each, which progressively decreases in size posteriorly. Hooks are backwardly curved and robust and tapering with a sharp, pointed tip, striations on the surface and a manubrium at its base. The body is aspinose, trunk surface with micropores and pits and proboscis surface with papilliform structures. The body wall is with five dorsal and two ventral hypodermal nuclei, along with lacunar canals connected by circular anastomoses. Lemnisci are subequal, small lemnisci are uninucleated, and large ones are binucleated. The cement gland is oval, with four giant nuclei; bursa is with many sensory cells. Eggs are elliptical, with concentric shells, and polar prolongation is absent. In the molecular and phylogenetic analyses based on the 18S ribosomal DNA region, the present species stands out with a high bootstrap value and is positioned as a sister branch of N. (N.) dimorphospinus. Based on the differences in morphology, morphometry and molecular and phylogenetic analyses, the present species of acanthocephalan infecting M. cephalus is considered as new, and the name Neoechinorhynchus (Neoechinorhynchus) cephali n. sp. is proposed.
Topics: Acanthocephala; Animals; Female; Fish Diseases; Helminthiasis, Animal; India; Male; Phylogeny; Smegmamorpha
PubMed: 34410496
DOI: 10.1007/s00436-021-07252-2 -
Biological Reviews of the Cambridge... Oct 2020Several parasite species have the ability to modify their host's phenotype to their own advantage thereby increasing the probability of transmission from one host to... (Meta-Analysis)
Meta-Analysis Review
Several parasite species have the ability to modify their host's phenotype to their own advantage thereby increasing the probability of transmission from one host to another. This phenomenon of host manipulation is interpreted as the expression of a parasite extended phenotype. Manipulative parasites generally affect multiple phenotypic traits in their hosts, although both the extent and adaptive significance of such multidimensionality in host manipulation is still poorly documented. To review the multidimensionality and magnitude of host manipulation, and to understand the causes of variation in trait value alteration, we performed a phylogenetically corrected meta-analysis, focusing on a model taxon: acanthocephalan parasites. Acanthocephala is a phylum of helminth parasites that use vertebrates as final hosts and invertebrates as intermediate hosts, and is one of the few parasite groups for which manipulation is predicted to be ancestral. We compiled 279 estimates of parasite-induced alterations in phenotypic trait value, from 81 studies and 13 acanthocephalan species, allocating a sign to effect size estimates according to the direction of alteration favouring parasite transmission, and grouped traits by category. Phylogenetic inertia accounted for a low proportion of variation in effect sizes. The overall average alteration of trait value was moderate and positive when considering the expected effect of alterations on trophic transmission success (signed effect sizes, after the onset of parasite infectivity to the final host). Variation in the alteration of trait value was affected by the category of phenotypic trait, with the largest alterations being reversed taxis/phobia and responses to stimuli, and increased vulnerability to predation, changes to reproductive traits (behavioural or physiological castration) and immunosuppression. Parasite transmission would thereby be facilitated mainly by changing mainly the choice of micro-habitat and the anti-predation behaviour of infected hosts, and by promoting energy-saving strategies in the host. In addition, infection with larval stages not yet infective to definitive hosts (acanthella) tends to induce opposite effects of comparable magnitude to infection with the infective stage (cystacanth), although this result should be considered with caution due to the low number of estimates with acanthella. This analysis raises important issues that should be considered in future studies investigating the adaptive significance of host manipulation, not only in acanthocephalans but also in other taxa. Specifically, the contribution of phenotypic traits to parasite transmission and the range of taxonomic diversity covered deserve thorough attention. In addition, the relationship between behaviour and immunity across parasite developmental stages and host-parasite systems (the neuropsychoimmune hypothesis of host manipulation), still awaits experimental evidence. Most of these issues apply more broadly to reported cases of host manipulation by other groups of parasites.
Topics: Acanthocephala; Amphipoda; Animals; Host-Parasite Interactions; Parasites; Phenotype; Phylogeny
PubMed: 32342653
DOI: 10.1111/brv.12606