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1.
Sci Rep ; 12(1): 9667, 2022 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-35690629

RESUMO

Anisakids are widespread marine parasites of medical, veterinary and economic relevance. They infect marine natural hosts but humans can accidentally acquire the fish-borne zoonosis anisakiasis by ingesting infected raw fishes or mollusks. Among the several species described, Anisakis pegreffii is one of the main etiological agent of the disease, in particular in the Mediterranean area. Despite the growing evidence of miRNAs involvement in host-parasite interplay, and the emerging role of exosomal microvesicles in shuttling them between different cell types (and sometime across species), no information on miRNAs from any Anisakis species is presently available. In this study we isolated extracellular vesicles (EVs) released by Anisakis pegreffii infective third-stage larvae (L3) and analyzed by RNA-seq small RNAs from both L3 and EVs. We showed by nanoparticle tracking analysis that L3 release in culture medium particles of size compatible with the one of extracellular vesicles. A catalogue of 156 miRNAs from A. pegreffii was compiled by sequence comparison to evolutionary close species and miRNA prediction software. Using differential expression analysis, we identified a small number of highly abundant miRNAs in larvae and extracellular vesicles fractions whose potential biological relevance may deserve future investigation. Finally, A. pegreffii miRNAs were compared to those described in other parasitic helminths and predicted targets among human genes were searched, suggesting their potential involvement during infection.


Assuntos
Anisakis , Vesículas Extracelulares , Doenças dos Peixes , MicroRNAs , Parasitos , Animais , Anisakis/genética , Vesículas Extracelulares/genética , Doenças dos Peixes/genética , Doenças dos Peixes/parasitologia , Peixes/genética , Peixes/parasitologia , Larva/genética , MicroRNAs/genética , Parasitos/genética
2.
Parasitol Res ; 121(7): 1937-1949, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35589866

RESUMO

Fish parasite communities can be directly influenced by characteristics of host species. However, little is known about the host-parasite relationships in commercially important fish of the southeastern Atlantic. To address this knowledge gap, a comparative analysis of the parasite communities of three sympatric Clupeiformes was conducted. Cetengraulis edentulus (Engraulidae), Opisthonema oglinum (Clupeidae) and Sardinella brasiliensis (Clupeidae) were collected from an estuarine lagoon near Rio de Janeiro, Brazil. Prevalence, abundance and aggregation were estimated for infrapopulations; richness, diversity, evenness and dominance for infracommunities. The three component communities were compared using both quantitative and qualitative components. Canonical discriminant analysis was used to determine if a host population could be characterised by the component community of its parasites. Multivariate models revealed that host species, a proxy for diet and phylogenetic relationships, was the main factor influencing the composition of parasite infracommunities. Diet was found to be the main factor shaping the communities of endoparasites, in which digeneans were dominant and best indicator of host population. Ectoparasites (copepods, isopods and monogeneans) displayed strong host-specificity with some species restricted to a single host population. The similarity of the component communities of the two clupeid populations demonstrated the influence of host phylogeny. Parasite infracommunities exhibited low diversity and high dominance, with many taxa restricted to a single host species (specialists) and few occurring in more than one (generalists). Host phylogeny and by extension, diet, morphology and coevolution with parasites appear to be important factors in determining the host-parasite relationships of clupeiform fish in the southeastern Atlantic.


Assuntos
Doenças dos Peixes , Parasitos , Animais , Brasil/epidemiologia , Doenças dos Peixes/epidemiologia , Doenças dos Peixes/parasitologia , Peixes/parasitologia , Interações Hospedeiro-Parasita , Parasitos/genética , Filogenia
3.
Syst Parasitol ; 99(4): 491-523, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35553301

RESUMO

In 2014-2015 and 2019-2021, teleost fishes off Galindez Island (Antarctic Peninsula) were examined for trematodes. Combined morphological and molecular analyses revealed the presence of eight trematode species of four families (Hemiuridae, Lecithasteridae, Opecoelidae, Lepidapedidae) from five fish species. Only adult trematodes were found and all of them are Antarctic endemics with their congeners occurring on other continents. The hemiuroids, Elytrophalloides oatesi (Leiper & Atkinson, 1914), Genolinea bowersi (Leiper & Atkinson, 1914), and Lecithaster macrocotyle Szidat & Graefe, 1967 belong to the most common Antarctic species and together with Lepidapedon garrardi (Leiper & Atkinson, 1914) and Neolebouria georgiensis Gibson, 1976 they were recorded as the least host-specific parasites. The originally sub-Antarctic Neolepidapedon macquariensis Zdzitowiecki, 1993 is a new record for the Antarctic Peninsula and Parachaenichthys charcoti (Vaillant), is a new host record. Neolebouria terranovaensis Zdzitowiecki, Pisano & Vacchi, 1993 is considered a synonym of N. georgiensis because of identical morphology and dimensions. The currently known phylogenetic relationships within the studied families are supported, including the polyphyly of Macvicaria Gibson & Bray, 1982 with the future need to accommodate its Antarctic species in a new genus. The validity of M. georgiana (Kovaleva & Gaevskaja, 1974) and M. magellanica Laskowski, Jezewski & Zdzitowiecki, 2013 needs to be confirmed by further analyses. Genetic sequence data are still scarce from Antarctica, and more studies applying integrative taxonomic approaches and large-scale parasitological examinations of benthic invertebrates are needed to match sequences of larval stages to those of well-characterised adults and to elucidate trematode life-cycles.


Assuntos
Trematódeos , Animais , Regiões Antárticas , Peixes/parasitologia , Ilhas , Filogenia , Especificidade da Espécie
4.
Syst Parasitol ; 99(4): 403-417, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35553302

RESUMO

A new cryptogonimid trematode, Siphoderina hustoni n. sp., is reported, collected off Lizard Island, Queensland, Australia, from the Maori snapper Lutjanus rivulatus (Cuvier). The new species is moderately distinctive within the genus. It is larger and more elongate than most other species of Siphoderina Manter, 1934, has the shortest forebody of any, a relatively large ventral sucker, a long post-testicular zone, and is perhaps most recognisable for the substantial space in the midbody between the ventral sucker and ovary devoid of uterine coils and vitelline follicles, the former being restricted to largely posterior to the ovary and the latter distributed from the level of the anterior testis to the level of the ovary. In phylogenetic analyses of 28S ribosomal DNA, the new species resolved with the other nine species of Siphoderina for which sequence data are available, all of which are from Queensland waters and from lutjanid and haemulid fishes. Molecular barcode data were also generated, for the ITS2 ribosomal DNA and cox1 mitochondrial DNA markers. The new species is the first cryptogonimid known from L. rivulatus and the first metazoan parasite reported from that fish in Australian waters.


Assuntos
Doenças dos Peixes , Trematódeos , Infecções por Trematódeos , Animais , Austrália , DNA Ribossômico/genética , Feminino , Doenças dos Peixes/parasitologia , Peixes/parasitologia , Humanos , Masculino , Filogenia , Especificidade da Espécie , Trematódeos/genética , Infecções por Trematódeos/parasitologia
5.
Syst Parasitol ; 99(4): 477-489, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35583766

RESUMO

The family Pennellidae comprises ecto- and mesoparasitic copepods on marine fishes. Although a preliminary scheme of phylogenetic relationships of pennellids based on morphological characters exists, it is difficult to objectively define character states because of their highly modified bodies and reduced appendages. This molecule-based study analysed phylogenetic relationships among seven genera and 12 species of pennellids, using 18S and 28S ribosomal DNA sequences in order to infer evolutionary trends within the family. Our molecular analysis recovered three clades (Clade-I, Peniculus; Clade-II, Haemobaphes-Lernaeocera-Phrixocephalus-Exopenna-Lernaeenicus radiatus; and Clade-III, Pennella-Lernaeenicus spp.). This result was congruent with some of the morphology-based phylogenetic relationships previously proposed but did not support a sister group comprising Exopenna, Phrixocephalus and Pennella. The second and third offshoots after the divergence of Clade-I species are characterized by reduced body tagmosis and changes in lifestyle from ectoparasites to mesoparasites. In some gill parasites of Clade-II, their sigmoid-shaped bodies and coiled egg strings have likely evolved in adaptation to the limited available space within the gill cavities of the hosts. Phrixocephalus is an eye parasite in Clade-II, which also has coiled egg strings, may have descended from an ancestral gill parasite. All species of Clade-III are characterized by the possession of a head region with processes deeply embedded into the host tissues and functioning as an anchor.


Assuntos
Copépodes , Animais , Evolução Biológica , Peixes/parasitologia , Filogenia , Especificidade da Espécie
6.
Parasite ; 29: 28, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35588271

RESUMO

Cyclocotyla bellones Otto, 1823 (Monogenea, Diclidophoridae) is one of the few monogenean species reported as hyperparasitic: the worms dwell on cymothoid isopods, themselves parasites of the buccal cavity of fishes. We present here observations based on newly collected monogenean specimens from Ceratothoa parallela (Otto, 1828), an isopod parasite of Boops boops off Algeria and also investigated its diet to address whether Cy. bellones is indeed a hyperparasite, i.e., whether it feeds on the isopod. We also compared the body shape of various monogeneans belonging to the same family as Cy. bellones, the Diclidophoridae, including Choricotyle cf. chrysophryi Van Beneden & Hesse, 1863, collected from Pagellus acarne off Algeria. No morphological character of the anterior organs suggested any special adaptation in Cy. bellones to the perforation of the crustacean cuticle. The wall of the oesophagus and of the intestine of Cy. bellones was lined with a dark pigment similar to what is usually observed in haematophagous polyopisthocotyleans, and which is derived from ingested fish blood. We noticed that an anterior elongate stem exists only in diclidophorids dwelling on parasitic isopods and never in those attached to the gills. We hypothesize that the anterior stem of the body of Cy. bellones is an anatomical adaptation for the monogenean to feed on the fish while dwelling on the isopod. We thus consider that Cy. bellones is an epibiont of the parasitic crustacean, as it uses it merely as an attachment substrate, and is not a true hyperparasite.


Title: Vraiment un hyperparasite, ou simplement un épibionte sur un parasite ? Le cas de Cyclocotyla bellones (Monogenea, Diclidophoridae). Abstract: Cyclocotyla bellones Otto, 1823 (Monogenea, Diclidophoridae) est l'une des rares espèces de monogènes signalées comme hyperparasites : les vers vivent sur des isopodes cymothoïdes, eux-mêmes parasites de la cavité buccale des poissons. Nous présentons ici des observations basées sur des spécimens de monogènes nouvellement collectés de Ceratothoa parallela (Otto, 1828), un isopode parasite de Boops boops au large de l'Algérie et avons également étudié son régime alimentaire pour déterminer si Cy. bellones est bien un hyperparasite (c'est-à-dire, se nourrit-il de l'isopode ?). Nous avons également comparé la morphologie de divers monogènes appartenant à la même famille que Cy. bellones, les Diclidophoridae, dont Choricotyle cf. chrysophryi Van Beneden & Hesse, 1863, collecté sur Pagellus acarne au large de l'Algérie. Aucun caractère morphologique des organes antérieurs ne suggérait d'adaptation particulière à la perforation de la cuticule des crustacés chez Cy. bellones. La paroi de l'œsophage et de l'intestin de Cy. bellones était tapissée d'un pigment foncé semblable à ce que l'on observe habituellement chez les Polyopisthocotylea hématophages, et qui est issu du sang de poisson ingéré. Nous avons remarqué qu'une partie allongée antérieure n'existe que chez les Diclidophoridae vivant sur des isopodes parasites et jamais chez ceux attachés aux branchies. Nous émettons l'hypothèse que la partie antérieure du corps de Cy. bellones est une adaptation anatomique permettant au monogène de se nourrir du poisson tout en vivant sur l'isopode. Nous considérons donc que Cy. bellones est un épibionte du crustacé parasite, puisqu'il ne l'utilise que comme substrat pour son attachement, et n'est pas un véritable hyperparasite.


Assuntos
Doenças dos Peixes , Parasitos , Perciformes , Trematódeos , Animais , Doenças dos Peixes/parasitologia , Peixes/parasitologia , Brânquias/parasitologia , Perciformes/parasitologia , Trematódeos/anatomia & histologia
7.
Parasitology ; 149(8): 1065-1077, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35443901

RESUMO

In the Anisakidae family, there are nematodes, most of which are parasitic for important commercial fish species. Both public health risks and socio-economic problems are attributed to these parasites. Despite these concerns, knowledge of the metabolism of these parasites remains unknown. Therefore, the main objective of this study was to investigate the receptors of drugs and oxidative metabolic status of two Anisakidae species, Pseudoterranova decipiens (s. s.) and Contracaecum osculatum (s. s.), under the influence of anthelminthic drugs, ivermectin (IVM) and pyrantel (PYR), at different concentrations: 1.56, 3.125 and 6.25 µg mL−1 of culture medium for 3, 6, 9, 12 and 72 h. The mRNA expressions of the γ-aminobutyric acid receptor, acetylcholine receptor subunits, adenosine triphosphate-binding cassette transporters and antioxidative enzymes were determined. The total antioxidant capacity and glutathione S-transferase activity were also examined. To the best of the authors' knowledge, this is the first time that IVM and PYR have been tested against these parasitic nematodes.


Assuntos
Ascaridoidea , Doenças dos Peixes , Animais , Ascaridoidea/genética , Doenças dos Peixes/parasitologia , Peixes/parasitologia
8.
Parasit Vectors ; 15(1): 149, 2022 Apr 27.
Artigo em Inglês | MEDLINE | ID: mdl-35477556

RESUMO

BACKGROUND: Diplozoidae are monogenean (Monogenea: Polyopisthocotylea) fish parasites characterised by a unique life history: two larvae permanently fuse into an X-shaped "Siamese" organism. Taxonomy and phylogeny of Diplozoidae and Polyopisthocotylea remain unresolved due to the unavailability of molecular markers with sufficiently high resolution. Mitogenomes may be a suitable candidate, but there are currently only 12 available for the Polyopisthocotylea (three for Diplozoidae). The only available study of diplozoid mitogenomes found unique base composition patterns and elevated evolution rates in comparison with other Monogenean mitogenomes. METHODS: To further explore their evolution and generate molecular data for evolutionary studies, we sequenced the complete mitogenomes of two Diplozoidae species, Paradiplozoon homoion and Paradiplozoon yarkandense, and conducted a number of comparative mitogenomic analyses with other polyopisthocotyleans. RESULTS: We found further evidence that mitogenomes of Diplozoidae evolve at a unique, elevated rate, which was reflected in their exceptionally long branches, large sizes, unique base composition, skews, and very low gene sequence similarity levels between the two newly sequenced species. They also exhibited remarkably large overlaps between some genes. Phylogenetic analysis of Polyopisthocotylea resolved all major taxa as monophyletic, and Mazocraeidea was split into two major clades: (Diplozoidae) + (all four remaining families: Diclidophoridae, Chauhaneidae, Mazocraeidae and Microcotylidae). It also provided further confirmation that the genus Paradiplozoon is paraphyletic and requires a taxonomic revision, so the two species may have to be renamed Indodiplozoon homoion and Diplozoon yarkandense comb. nov. CONCLUSIONS: Although our findings indicate that mitogenomes may be a promising tool for resolving the phylogeny of Polyopisthocotylea, elevated evolutionary rates of Diplozoidae may cause phylogenetic artefacts, so future studies should pay caution to this problem. Furthermore, as the reason for their elevated evolution remains unknown, Diplozoidae are a remarkably interesting lineage for other types of evolutionary mitogenomic studies.


Assuntos
Genoma Mitocondrial , Trematódeos , Animais , Composição de Bases , Peixes/parasitologia , Humanos , Filogenia , Trematódeos/genética
9.
Rev Med Suisse ; 18(776): 634-638, 2022 Apr 06.
Artigo em Francês | MEDLINE | ID: mdl-35385613

RESUMO

Anisakis simplex is a parasitic worm. It infects marine mammals that feed on fish and cephalopods, its intermediary hosts. Human disease is caused by accidental ingestion of Anisakis larvae. Upon consumption of contaminated fish, cuttlefish or squid, human may develop two distinct clinical pictures: Anisakiasis is provoked by living larvae penetrating the digestive mucosa. Allergy is caused by IgE-mediate hypersensitivity to living or dead larvae in a previously sensitized individual. Anisakiasis may manifests with violent epi gastric pain, acute abdomen or eosinophilic gastroenteritis. The larvae may be visualized by endoscopy or histology. The main Anisakis allergens are not denaturated by heat or cold and resist to digestion. Allergy diagnosis relies on careful history and detection of specific IgE.


Anisakis simplex est un ver parasite (helminthe) du groupe des nématodes. Il infeste les mammifères marins se nourrissant de poissons et de céphalopodes, ses hôtes intermédiaires. Chez l'homme, l'ingestion de poissons, de calamars ou de seiches contaminés est responsable de 2 tableaux cliniques. L'anisakiase est provoquée par la pénétration de la muqueuse digestive par des larves vivantes. L'allergie est une réaction IgE (immunoglobuline E) médiée aux parasites morts ou vivants chez une personne préalablement sensibilisée. L'anisakiase occasionne des épigastralgies, un abdomen aigu ou de manière plus sournoise une gastroentérite à éosinophiles. Les larves sont visualisables par endoscopie ou à l'histologie. Les principaux allergènes d'Anisakis résistent à la cuisson et à la digestion. Le diagnostic d'allergie se base sur l'anamnèse et la détection d'IgE spécifiques.


Assuntos
Anisaquíase , Anisakis , Hipersensibilidade , Animais , Anisaquíase/diagnóstico , Anisaquíase/epidemiologia , Anisaquíase/parasitologia , Peixes/parasitologia , Humanos , Imunoglobulina E , Larva , Mamíferos , Alimentos Marinhos/efeitos adversos , Alimentos Marinhos/parasitologia
10.
Int J Food Microbiol ; 367: 109591, 2022 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-35231680

RESUMO

Anisakidae, mainly represented by the species Anisakis simplex and Pseudoterranova decipiens, are one of the most commonly zoonotic nematodes present in marine fish species. Apart from public health risks directly linked to the parasite itself, little is known on the effects of the migrating nematodes on the hygienic quality of the fish fillet due to bacteria it carries. In the present study, the cultivated bacterial community on and in individual P. decipiens larvae deriving from codfish is reported. Four isolation media were included and evaluated to increase the bacterial diversity isolated, and identification of the bacterial growth was performed by a combination of Matrix-Assisted Laser Desorption Ionization Time-Of-Flight mass spectrometry and 16S rRNA gene sequencing. Results revealed that the microbiota of P. decipiens larvae comprises both potential spoilage bacteria and human opportunistic pathogens, and that a combined isolation on the general isolation medium tryptone soy agar and a medium supplemented with artificial seawater resulted in the highest bacterial recovery in terms of diversity and enumeration. Dissimilarity analysis also revealed similar, though unique, bacterial communities between nematodes originating from the same fish suggesting that anisakid microbiota compositions are reflections of the microbial assemblages in the fish host as an individual, and that the gut microbiome is diverse within gadoid fish species originating from the same geographical habitat. Future research should, based on the results in the present study, further elaborate on the comparison of the bacterial communities of both the larva and the codfish from which it was isolated, and, explore the extrapolation potential towards other fish and nematode species. Also, the actual degree of risk beyond the simple presence of the parasite due to carriage of opportunistic bacteria should be examined, as well as the nematode's true effect on spoilage.


Assuntos
Anisakis , Doenças dos Peixes , Gadus morhua , Microbiota , Parasitos , Animais , Bactérias/genética , Doenças dos Peixes/parasitologia , Peixes/parasitologia , Gadus morhua/genética , Gadus morhua/parasitologia , Larva , Parasitos/genética , RNA Ribossômico 16S/genética
11.
Rev Bras Parasitol Vet ; 31(1): e020421, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35293430

RESUMO

Betta rubra is an ornamental freshwater fish endemic to northern Sumatra, Indonesia. The B. rubra population has decreased in recent decades, and is classified as an endangered species in the IUCN Red List. This study aims to report for the first time infection by L. cyprinacea in B. rubra harvested from the Aceh Besar region of Indonesia. The fish samples were obtained from the Cot Bira tributaries, Aceh Besar District, Indonesia from January to December 2020. The results showed that the parasite infected 6 out of 499 samples in August and September, with a prevalence and intensity rate of 1% and 2 parasites/fish, respectively. The eyes and pectoral fins were the common infection sites. Despite B. rubra is not an optimal host (small size) for the parasite, this parasite might serve as additional threatening factors for the endangered B. rubra fish population.


Assuntos
Copépodes , Acetona/análogos & derivados , Animais , Peixes/parasitologia , Água Doce , Hidrazonas , Indonésia/epidemiologia
12.
J Helminthol ; 96: e24, 2022 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-35343406

RESUMO

The heterogeneous landscape of Nicaragua harbours a large diversity of freshwater fishes. The great Nicaraguan lakes, Managua and Nicaragua, and several adjacent crater lakes harbour numerous endemic fish species. However, information about their parasite fauna is still fragmentary. Here, we surveyed the great Nicaraguan lakes and four crater lakes and provide data for 17 metazoan parasite taxa infecting seven fish host species. We also gathered all the published records from the literature on the parasites reported from Nicaraguan freshwater fishes, as well as those for Costa Rica and Panama to discuss the region of Lower Central America as a whole. With this information we built a parasite-host and a host-parasite checklist. With data from near 50% of the native and endemic freshwater fishes in Nicaragua, the parasite fauna comprises 101 taxa in 51 fish species allocated in 11 families. Cichlids are the most diverse group of fishes in this region and have been the most extensively surveyed for their metazoan parasites. Helminths are the best-represented groups of metazoan parasites, with 42 trematodes, five cestodes, 24 monogeneans, two acanthocephalans, 20 nematodes and one hirudinean. Additionally, freshwater fishes are parasitized by copepods, branchiurans and oribatid mites. Even though the inventory is not yet complete, the patterns of diversity uncovered revealed promising information about the origin, biogeography and evolutionary history of the Nicaraguan freshwater fish parasite fauna. More studies are necessary to complete our knowledge about the diversity, host association and distribution of metazoan parasites in Nicaragua and other Central American countries.


Assuntos
Doenças dos Peixes , Parasitos , Animais , Biodiversidade , Doenças dos Peixes/parasitologia , Peixes/parasitologia , Água Doce , Humanos , Nicarágua , Parasitos/genética
13.
Parasitology ; 149(2): 239-252, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-35234594

RESUMO

Trematode taxonomy is mainly based on the morphological traits of adults. The identification of metacercariae is challenging because such traits are not developed in larval forms, and they even may show some level of morphological variability. Studies testing the potential correspondence between morphological differences and genetic variation of parasites are still lacking. The metacercariae of Posthodiplostomum minimum are probably the diplostomids more widely distributed in North and Middle American freshwater fish, and their intraspecific morphological variability has been attributed to the effect exerted by the host. Here, we tested the hypothesis whether they represent a single species, or a species complex by assessing the genetic divergence and phylogenetic relationships of metacercariae sampled from several host species in a wide geographical range across Middle America. The internal transcribed spacers (ITS1-5.8S-ITS2), and the mitochondrial COI gene were sequenced for 124 and 55 metacercariae, respectively. Phylogenetic analysis inferred from ITS sequences uncovered six well-supported monophyletic lineages. The six lineages show no correspondence to any Posthodiplostomum species for which sequences are available thus far in GenBank. Lineages exhibit some degree of host specificity; Lineages I, II, IV and V are primarily parasites of cyprinodontiforms of the families Poeciliidae, Goodeidae, Profundulidae and Fundulidae. In poeciliids there are at least four candidate species of Posthodiplostomum, some of them occurring in sympatry; instead, Lineages II and VI are exclusively parasites of cichlids. This study contributes to our understanding of the diversity of larval forms of diplostomids and provides an opportunity to further study their life cycles.


Assuntos
Doenças dos Peixes , Trematódeos , Infecções por Trematódeos , Animais , Doenças dos Peixes/parasitologia , Peixes/parasitologia , Água Doce , Variação Genética , Humanos , Metacercárias/anatomia & histologia , Filogenia , Infecções por Trematódeos/parasitologia , Infecções por Trematódeos/veterinária
14.
Parasitology ; 149(2): 234-238, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-35234596

RESUMO

The transmission of adult parasites from prey to predatory hosts has been demonstrated for some acanthocephalan and one cestode species. Derogenes lacustris (Digenea: Hemiuroidea: Derogenidae) is a generalist parasite that infects, as an adult, the stomach of native and introduced freshwater fishes in Andean Patagonia. In the present work, the post-cyclic transmission of D. lacustris from native Galaxias maculatus (Galaxiidae) to introduced Oncorhynchus mykiss (Salmonidae) was proved experimentally. The observed transmission rate for this experimental infection was 19%. The body length of D. lacustris on day 14 post-infection was significantly greater than before transmission. The number of eggs also increased significantly after transmission, showing that D. lacustris can survive, grow and continue with egg production for at least 2 weeks in predatory salmonids. This study provides the first experimental evidence of post-cyclic transmission of trematodes and the results suggest that post-cyclic parasitism enables this species to broaden its range of hosts and distribution ranges in Argentinean Patagonia.


Assuntos
Doenças dos Peixes , Oncorhynchus mykiss , Osmeriformes , Trematódeos , Animais , Argentina/epidemiologia , Doenças dos Peixes/parasitologia , Peixes/parasitologia , Água Doce , Osmeriformes/parasitologia
15.
Int J Parasitol ; 52(7): 469-474, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35358502

RESUMO

In recent years, several authors have warned that the number of trained experts in parasite taxonomy and systematics is declining rapidly, and that the whole field is at risk. However, to date there has been no quantitative analysis to support these claims. Here, we provide the first such assessment, focusing on helminths parasitic in fish as an example, and using a representative dataset comprising over 2000 helminth species described in the past two decades. Based on standard indices of inequality, we demonstrate that a small group of highly prolific taxonomists are associated with the vast majority of new species descriptions, indicating that the research output in parasite discovery is concentrated in the hands of a small number of individuals. This situation has not improved over time. Furthermore, there has been no turnover over time, i.e., no replacement of the most prolific taxonomists: the individual researchers ranking among the most prolific describers of new parasite helminth species in the past decade were generally also the most prolific in the decade before that. Finally, based on the year in which these most prolific taxonomists published their first species description, we estimate that a large proportion of them are in the latter stages of their career. Inequalities in research output are the norm across scientific disciplines. However, persistent inequality in the number of species description per author, coupled with the same individuals ranking as most prolific over time and a majority of them in late career, all combine to support earlier claims that parasite taxonomy may well face a crisis in the form of an impending loss of taxonomic expertise.


Assuntos
Helmintos , Parasitos , Animais , Biodiversidade , Peixes/parasitologia
16.
J Anim Ecol ; 91(5): 996-1009, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35332535

RESUMO

Although parasites are ubiquitous in marine ecosystems, predicting the abundance of parasites present within marine ecosystems has proven challenging due to the unknown effects of multiple interacting environmental gradients and stressors. Furthermore, parasites often are considered as a uniform group within ecosystems despite their significant diversity. We aim to determine the potential importance of multiple predictors of parasite abundance in coral reef ecosystems, including reef area, island area, human population density, chlorophyll-a, host diversity, coral cover, host abundance and island isolation. Using a model selection approach within a database of more than 1,200 individual fish hosts and their parasites from 11 islands within the Pacific Line Islands archipelago, we reveal that geographic gradients, including island area and island isolation, emerged as the best predictors of parasite abundance. Life history moderated the relationship; parasites with complex life cycles increased in abundance with increasing island isolation, while parasites with direct life cycles decreased with increasing isolation. Direct life cycle parasites increased in abundance with increasing island area, although complex life cycle parasite abundance was not associated with island area. This novel analysis of a unique dataset indicates that parasite abundance in marine systems cannot be predicted precisely without accounting for the independent and interactive effects of each parasite's life history and environmental conditions.


Assuntos
Parasitos , Animais , Recifes de Corais , Ecossistema , Peixes/parasitologia , Interações Hospedeiro-Parasita , Estágios do Ciclo de Vida
17.
Fish Shellfish Immunol ; 121: 516-534, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-35123696

RESUMO

Rodlet cells (RCs) are the enigmatic and distinctive pear-shaped cells had found in many tissues of marine and freshwater teleosts. They have a distinctive fibrous capsule or the cell cortex that envelopes conspicuous inclusions called rodlets, basally situated nucleus, and poorly developed mitochondria. The contraction of the cell cortex results in the expulsion of the cell contents through an apical opening. One hundred and thirty years since rodlet cells were first reported, many questions remain about their origin and a function. This review will present new evidence regarding the relationship between RCs and metazoan parasites, and a protozoan infecting organs of different fish species, and update the state of knowledge about the origin, structure and the function of these intriguing fish cells.


Assuntos
Peixes/parasitologia , Parasitos , Animais , Peixes/imunologia
18.
Acta Parasitol ; 67(2): 835-841, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35138573

RESUMO

PURPOSE: It has been suggested that the removal of infected viscera on board is responsible for the high prevalence of anisakid larvae present in wild fish species. The aim of this work is to assess the re-infection capacity of anisakid larvae in European seabasses, a natural host species for the parasite by feeding with pieces of parasitised hake liver under controlled experimental conditions. METHODS: To prove this potential link between manipulation and re-infestation, 50 farmed seabasses free of anisakid nematodes were fed with fresh hake liver pieces naturally infested with anisakid larvae. RESULTS: After digestion periods from 4 to 21 days, the seabasses showed a prevalence of Anisakis of 6%, and a low retention rate of 0.11 larvae/seabass after four days' digestion, and 0.0021 after 21 day digestion. Two nematodes were found in the intestine and in the visceral cavity, and 13 Anisakis were found partially digested in the stomach of one same individual after 4 day digestion. Results showed that only a small number of Anisakis ingested with the viscera were able to reinfect the seabasses, as most of the larvae seemed to be quickly digested or defecated. CONCLUSION: it seems that the availability of larvae that could re-enter the life cycle and re-infect a fish after the removal and discarding the infected viscera on board could be much less important than commonly believed.


Assuntos
Anisaquíase , Anisakis , Doenças dos Peixes , Gadiformes , Perciformes , Animais , Anisaquíase/epidemiologia , Anisaquíase/parasitologia , Anisaquíase/veterinária , Doenças dos Peixes/epidemiologia , Doenças dos Peixes/parasitologia , Peixes/parasitologia , Larva , Vísceras
19.
J Fish Biol ; 100(5): 1187-1194, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35184281

RESUMO

Eggs of acipenseriform fish infected with the parasite Polypodium hydriforme become enlarged during later stages of development. This study examined if the increase in size is due to the increase in nutrients or water in the infected eggs and if the polypodium eggs affect the nutrient levels of the neighbouring eggs in the ovary. Infected and uninfected eggs were collected from parasitized Paddlefish, Polyodon spathula, hosts and unparasitized individuals. Levels of water, protein, carbohydrates, lipids and amino acids were determined for each egg. Although there were nutritional differences between eggs infected with P. hydriforme and uninfected eggs there was no indication that there was an increase in resource allocation to the infected eggs. The amount of water was much higher in infected eggs, suggesting the size increase was due to a greater influx of water. Levels of free amino acids were much higher in infected eggs and we hypothesize they could be used to increase the solute concentration to increase the influx of water, a mechanism that is also used by marine teleosts.


Assuntos
Cnidários , Polypodium , Aminoácidos , Animais , Feminino , Peixes/parasitologia , Água
20.
Parasitol Res ; 121(3): 867-875, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35088135

RESUMO

Sphaeromyxa azevedoi n. sp. is described from the gall bladder of the goby Gobioides grahamae (Gobiidae) captured on the Paracauari River in Salvaterra, on Marajó Island, northern Brazil. A total of 50 G. grahamae specimens were analysed, and 15 (30%) were parasitised by the plasmodia and myxospore of Sphaeromyxa azevedoi n. sp. Large plasmodia were observed floating in the bile. These plasmodia were flat, rounded, oval or elongated, and of varying sizes. The mature myxospores, found singly or in pairs, were 27.1 ± 2.7 (20.5-30.1) µm Length and 3.8 ± 0.2 (3.5-4.4) µm Width in the valvular view. The myxospore has two polar capsules of equal size, 8.1 ± 0.6 (7.4-9.4) µm in length and 2.9 ± 0.2 (2.3-3.3) µm in width. A polar tubule was observed in each capsule, arranged perpendicularly to the principal axis, with three or four coils. The histological analysis showed that the plasmodia and myxospore are located in the lumen of the gall bladder, arranged in pairs, and the epithelium of the gall bladder presented multifocal necrosis. The SSU rDNA of Sphaeromyxa azevedoi n. sp. clusters in the 'balbianii' group of the Sphaeromyxa clade. The morphological characteristics and molecular phylogeny of Sphaeromyxa azevedoi n. sp. support its classification as a new species of the genus Sphaeromyxa, which represents an important advancement in the understanding of the diversity of the myxozoan parasite fauna of Brazilian fishes, especially considering that the new species may be detrimental to the host, a commercially important Brazilian fish species.


Assuntos
Doenças dos Peixes , Myxozoa , Doenças Parasitárias em Animais , Perciformes , Animais , DNA Ribossômico/genética , Doenças dos Peixes/parasitologia , Peixes/parasitologia , Vesícula Biliar/parasitologia , Doenças Parasitárias em Animais/parasitologia , Perciformes/parasitologia , Filogenia
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