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Parasitology Aug 2021Parasite infracommunities tend to be stochastic in nature, although environmental characteristics such as the type of water source in streams and host traits can have an...
Parasite infracommunities tend to be stochastic in nature, although environmental characteristics such as the type of water source in streams and host traits can have an effect on the biotic assemblages and by extension the parasite fauna. We examined the effect of water source and the rate of adult fish migration on the metazoan parasite infracommunities of conspecific juvenile brown trout, Salmo trutta L. among streams flowing into Lake Lucerne (Switzerland). Juvenile (1 to 2-year old) fish harboured higher parasite species richness in groundwater-fed than in surface water-fed streams, whereas the rate of fish migration did not affect infracommunity richness. Heteroxenous species were more common in groundwater-fed streams with high and medium rates of trout migration, whereas infracommunities in surface water-fed streams and streams with low rates of fish migration were dominated by one monoxenous parasite or lacked infections. Similarity in the parasite infracommunity composition of juvenile trout across streams was explained by the interaction between type of water source and adult migration rates. Our conclusions support that similarity in the parasite composition of resident freshwater conspecifics can be predicted by the local environmental settings and host migratory behaviour, whereas parasite richness is mainly influenced by the environmental characteristics.
Topics: Acanthocephala; Animal Migration; Animals; Biodiversity; Cestoda; Cestode Infections; Helminthiasis, Animal; Helminths; Prevalence; Rivers; Switzerland; Trematoda; Trematode Infections; Trout
PubMed: 34027845
DOI: 10.1017/S0031182021000780 -
Proceedings. Biological Sciences Mar 2021Parasitic worms (i.e. helminths) commonly infect multiple hosts in succession before reproducing. At each life cycle step, worms may fail to infect the next host, and...
Parasitic worms (i.e. helminths) commonly infect multiple hosts in succession before reproducing. At each life cycle step, worms may fail to infect the next host, and this risk accumulates as life cycles include more successive hosts. Risk accumulation can be minimized by having high establishment success in the next host, but comparisons of establishment probabilities across parasite life stages are lacking. We compiled recovery rates (i.e. the proportion of parasites recovered from an administered dose) from experimental infections with acanthocephalans, cestodes and nematodes. Our data covered 127 helminth species and 16 913 exposed hosts. Recovery rates increased with life cycle progression (11%, 29% and 46% in first, second and third hosts, respectively), because larger worm larvae had higher recovery, both within and across life stages. Recovery declined in bigger hosts but less than it increased with worm size. Higher doses were used in systems with lower recovery, suggesting that high doses are chosen when few worms are expected to establish infection. Our results indicate that growing in the small and short-lived hosts at the start of a complex life cycle, though dangerous, may substantially improve parasites' chances of completing their life cycles.
Topics: Acanthocephala; Animals; Helminths; Host-Parasite Interactions; Life Cycle Stages; Nematoda
PubMed: 33726588
DOI: 10.1098/rspb.2021.0142 -
Folia Parasitologica Apr 2023Strange oceanographic events such as El Niño and La Niña may have indirect effects on the local transmission processes of intestinal parasites due to the reduction or...
Strange oceanographic events such as El Niño and La Niña may have indirect effects on the local transmission processes of intestinal parasites due to the reduction or increase in populations of potential intermediate or definitive hosts. A total of 713 individuals of Lutjanus inermis (Peters) were collected over an 8-year period (October 2015 to July 2022) from Acapulco Bay, Mexico. Parasite communities in L. inermis were quantified and analysed to determine if they experienced interannual variations in species composition and structure as a result of local biotic and abiotic factors influenced by oceanographic events, such as El Niño-Southern Oscillation (ENSO), or La Niña, the cool phase of the ENSO climate pattern. Twenty-six taxa of metazoan parasites were recovered and identified: two Monogenea, eight Digenea, two Acanthocephala, four Nematoda, one Cestoda, seven Copepoda, and two Isopoda. Species richness at the component community level (8 to 17 species) was similar to reported richness in other species of Lutjanus Bloch. Parasite communities of L. inermis exhibited high inter-annual variation in the abundance of component species of parasite. However, the species richness and diversity were fairly stable over time. Climatic episodes of El Niño and La Niña probably generated notable changes in the structure of local food webs, thus indirectly influencing the transmission rates of intestinal parasite species. Changes in species composition and community structure of parasites possibly were due to variations in feeding behaviour during the events and differences in the host body size.
Topics: Humans; Animals; Parasites; Perciformes; Nematoda; El Nino-Southern Oscillation; Acanthocephala
PubMed: 37265202
DOI: 10.14411/fp.2023.010 -
Revista Brasileira de Parasitologia... 2023Parasites are important components of ecosystems and may contribute to the ecological aspects of their hosts and indicate the integrity of their environment. To identify...
Parasites are important components of ecosystems and may contribute to the ecological aspects of their hosts and indicate the integrity of their environment. To identify the gastrointestinal helminths of the South American fur seal, Arctocephalus australis, 52 animals found dead on the Rio Grande do Sul coast, Southern Brazil, were necropsied. All studied animals were parasitized, and 104,670 specimens of helminths from three phyla and 14 taxa were collected. Adult specimens represented five of the identified species: Contracaecum ogmorhini, Adenocephalus pacificus, Stephanoprora uruguayense, Ascocotyle (Phagicola) longa, and Corynosoma australe; and one of the identified genera: Strongyloides sp. Immature forms represented the other eight taxa: Anisakidae gen. sp., Anisakis sp., Pseudoterranova sp., Contracaecum sp., Tetrabothriidae gen. sp., Cestoda gen. sp., Corynosoma cetaceum, and Bolbosoma turbinella. The acanthocephalan C. australe was the most prevalent and abundant parasite, whereas Strongyloides sp. had the highest intensity. This is the first record of the nematode Anisakis sp., digenean S. uruguayense, and acanthocephalan B. turbinella in this host. Trophic generalist species such as A. australis can be good indicators of the composition of the helminth fauna of their ecosystems, indicating the presence of zoonotic parasites transmitted by the consumption of fish.
Topics: Animals; Fur Seals; Ecosystem; Helminths; Acanthocephala; Brazil
PubMed: 36820736
DOI: 10.1590/S1984-29612023012 -
Folia Parasitologica Jun 2021Morphological characteristics of the acanthocephalan Polymorphus minutus (Goeze, 1782), which was collected from the duck Anas platyrhynchos Linnaeus in the Czech...
Morphological characteristics of the acanthocephalan Polymorphus minutus (Goeze, 1782), which was collected from the duck Anas platyrhynchos Linnaeus in the Czech Republic, are described. The mitochondrial (mt) genome of P. minutus was sequenced, with a total length of 14,149 bp, comprising 36 genes including 12 protein coding genes (PCGs), 22 transfer RNA (tRNA) genes and two ribosomal RNA genes (rrnL and rrnS). This genome is similar to the mt genomes of other syndermatan species. All these genes were encoded on the same DNA strand and in the same orientation. The overall nucleotide composition of the P. minutus mt genome was 38.2% T, 27.3% G, 26.2% A, and 8.3% C. The amino acid sequences of 12 PCGs for mt genomes of 28 platyzoans, including P. minutus, were used for phylogenetic analysis, and the resulting topology recovers P. minutus as sister to Southwellina hispida (Van Cleave, 1925), and the two taxa form a sister clade to Centrorhynchus aluconis (Müller, 1780) and Plagiorhynchus transversus (Rudolphi, 1819), which are all species in the Palaeacanthocephala, thus supporting the monophyly of this class.
Topics: Acanthocephala; Animals; Bird Diseases; Czech Republic; Ducks; Female; Genome, Helminth; Genome, Mitochondrial; Helminthiasis, Animal; Male; Phylogeny
PubMed: 34152291
DOI: 10.14411/fp.2021.015 -
Folia Parasitologica Jan 2022Specimens of Neoechinorhynchus (Neoechinorhynchus) poonchensis sp. n. are described from Schizothorax richardsonii (Gray) in the Poonch River, Jammu and Kashmir....
The morphological and molecular description of Neoechinorhynchus (Neoechinorhynchus) poonchensis sp. n. from Schizothorax richardsonii (Gray) in Poonch, Jammu and Kashmir, India.
Specimens of Neoechinorhynchus (Neoechinorhynchus) poonchensis sp. n. are described from Schizothorax richardsonii (Gray) in the Poonch River, Jammu and Kashmir. Specimens are thick-walled with dissimilar dorsal and ventral para-receptacle structures, anteriorly manubriated hooks, two giant nuclei in each lemniscus and many subcutaneousy. The lemnisci barely overlap the larger anterior testis, the cement gland has eight giant nuclei, and the seminal vesicle is large with thin walls. The vagina is unremarkable but the long uterus is made up of four specialised regions. Neoechinorhynchus rigidus (Van Cleave, 1928), resembles N. poonchensis sp. n. It is distinguished from N. poonchensis sp. n. by having smaller trunk, proboscis, and male reproductive structures, equal testes, unequal lemnisci with three giant nuclei each, and much larger anterior proboscis hook (130 μm in males) than that originally described by Van Cleave (1928) (70 μm in a female). Anterior hook length alone is sufficient to conclude that the N. rigidus of Datta (1937) is not the same species as the N. rigidus of Van Cleave (1928). Van Cleave's (1928) species remains valid and that of Datta (1937) is considered a different species named Neoechinorhynchus pseudorigidus sp. n., herein. Micropores of N. poonchensis sp. n. have variable distribution in different trunk regions and the Energy Dispersive X-ray analysis demonstrated higher levels of sulfur and lower levels of calcium and phosphorus. Sequences of the 18S rDNA gene from nuclear DNA, and cytochrome c oxidase subunit I (cox1) from mitochondrial DNA of N. poonchensis sp. n. were amplified and aligned with other sequences available on GenBank. Maximum likelihood (ML) and Bayesian inference (BI) analyses inferred for 18S rDNA and cox1 showed that N. poonchensis sp. n. was nested in a separate clade.
Topics: Acanthocephala; Animals; Bayes Theorem; Cyprinidae; Female; Fish Diseases; Helminthiasis, Animal; Male
PubMed: 35098927
DOI: 10.14411/fp.2022.001 -
Helminthologia Mar 2022The gray snapper is a commercially important fish species along its distribution range in the western Atlantic Ocean. However, despite its importance, there is still...
The gray snapper is a commercially important fish species along its distribution range in the western Atlantic Ocean. However, despite its importance, there is still little knowledge about its parasitic fauna for the Mexican coasts of the Gulf of Mexico. The aims of this research were to generate a list of the parasitic fauna present in juvenile gray snapper from a coastal lagoon located in southeastern Mexico, to evaluate the infection levels of parasites and to determine the relationship between the abundance of parasites and the fish size and condition factor. Samples of (12 - 29.2 mm) were obtained in two periods of the year (dry and rainy seasons) to examine the intra-annual variability of its parasitic fauna. A total of 17 parasite species were recorded belonging to six taxonomic groups (Myxozoa, Monogenea, Digenea, Cestoda, Nematoda and Acanthocephala). The highest levels of infection (abundance, prevalence and intensity of infection) were found for the monogeneans and . There were no significant correlations between the total abundance of parasites and the fish condition and size (total length) in not any of the two seasons studied, suggesting that the body size and the biological condition index of the host did not directly influence the abundance of parasites in early life stages of . Moreover, the species of parasites found that could be zoonotic for humans through the consumption of raw or inadequately cooked fish were the nematodes sp. type 1, sp. type 2, and sp. The presence of the monogeneans and was also highlighted because these ectoparasite species are known to cause harm to fish under culture systems. All the parasite species found in this study, except nematodes, were new records of geographic distribution.
PubMed: 35601767
DOI: 10.2478/helm-2022-0003 -
Parasitology Dec 2022In recent years, treating host–parasite associations as bipartite interaction networks has proven a powerful tool to identify structural patterns and their likely...
In recent years, treating host–parasite associations as bipartite interaction networks has proven a powerful tool to identify structural patterns and their likely causes in communities of fish and their parasites. Network analysis allows for both community-level properties to be computed and investigated, and species-level roles to be determined. Here, using data from 31 host–parasite interaction networks from local fish communities around the world, we test for latitudinal trends at whole-network level, and taxonomic patterns at individual parasite species level. We found that while controlling for network size (number of species per network), network modularity, or the tendency for the network to be subdivided into groups of species that interact mostly with each other, decreased with increasing latitude. This suggests that tropical fish–parasite networks may be more stable than those from temperate regions in the event of community perturbations, such as species extinction. At the species level, after accounting for the effect of host specificity, we observed no difference in the centrality of parasite species within networks between parasites with different transmission modes. However, species in some taxa, namely branchiurans, acanthocephalans and larval trematodes, generally had higher centrality values than other parasite taxa. Because species with a central position often serve as module connectors, these 3 taxa may play a key role in whole-network cohesion. Our results highlight the usefulness of network analysis to reveal the aspects of fish–parasite community interactions that would otherwise remain hidden and advance our understanding of their evolution.
Topics: Animals; Parasites; Host-Parasite Interactions; Fish Diseases; Fishes; Acanthocephala
PubMed: 35768403
DOI: 10.1017/S0031182022000944 -
Annals of Parasitology 2023Acanthocephalans are grouped in a single phylum, having a cosmopolitan distribution and subdivided into several genera. Although species of this parasite genus have...
Acanthocephalans are grouped in a single phylum, having a cosmopolitan distribution and subdivided into several genera. Although species of this parasite genus have birds and mammals as definitive hosts, they have been reported in amphibians and reptiles, and have been noted as paratenic hosts. In this study we report the record of Rhinella major as a new paratenic host for the Centrorhynchus sp. from an urban area of the Brazilian Amazon. In this study, for the morphometric measurements to take place, the parasitic specimens found were fixed and preserved in an alcoholic liquid medium and the identification of the parasites found were confirmed by specialized literature. The parasitological statistical parameters followed the proposed ecological concepts, calculating the parasite prevalence, intensity, average intensity and average abundance indices with confidence intervals. In the present study, two morphotypes of Acontochephala were found parasitizing R. major. In this study we report the record of R. major as a new paratenic host for the Centrorhynchus sp.
Topics: Animals; Anura; Brazil; Acanthocephala; Birds; Reptiles; Mammals
PubMed: 38164747
DOI: 10.17420/ap6902.512 -
Revista Brasileira de Parasitologia... 2021As the second-largest Neotropical carnivore, cougars (Puma concolor) are especially important for maintenance of the biodiversity and ecosystem health. Five wild adult...
As the second-largest Neotropical carnivore, cougars (Puma concolor) are especially important for maintenance of the biodiversity and ecosystem health. Five wild adult cougars (Puma concolor), found roadkilled in highways in the Northeastern region of São Paulo, were evaluated in search for parasites. Ten species representing nine families were identified. The most prevalent helminths were Uncinaria bidens, Lagochilascaris major, Spirometra sp., and Oncicola canis, followed by Cylicospirura subaequalis, Toxascaris leonina, Taenia omissa, Echinococcus sp., Filaroides sp. and Oncicola oncicola. It is important to note that some helminths found in this study, such as L. major, Spirometra sp., O. oncicola, O. canis, Echinococcus sp., T. leonina, C. subaequalis, and Filaroides sp. are known to affect domestic carnivores, which may indicate interaction between wild and domestic hosts. This study represents a new host record for four of the species found in cougars, U. bidens, L. major, O. canis, and Filaroides sp., and new locality records for U. bidens, T. leonina, C. subaequalis, and Filaroides sp.
Topics: Acanthocephala; Animals; Brazil; Ecosystem; Helminths; Puma
PubMed: 33787736
DOI: 10.1590/S1984-29612021008