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1.
Int J Parasitol Parasites Wildl ; 22: 229-233, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-38023346

RESUMEN

Specimens of the sandhopper Orchestoidea tuberculata (Amphipoda; Talitridae) collected from sandy beaches in south-central Chile, were found to be parasitized by juvenile mermithids, constituting the first record of a mermithid infecting a marine amphipod in Chile. A morphological description of juveniles is provided. Sequence analyses based on mitochondrial COI and nuclear 18S rDNA of the mermithids showed extremely low genetic variation. Phylogenetic analyses indicate that the mermithid is more closely related to Hexamermis agrotis, which parasitize Coleoptera, than to Thaumamermis zealandica, which parasitizes New Zealand confamilial talitrid amphipods.

2.
Parasite ; 30: 42, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37855712

RESUMEN

Profilicollis rancoensis n. sp. is the tenth species of Profilicollis Meyer, 1931 which includes 9 other species mostly known from marine decapod crabs and shore birds. Cystacanths of P. rancoensis are described from the dominant freshwater crab Aegla abtao in Ranco Lake, Chile and are morphologically distinguished from cystacanths of the 9 other species based on a combination of 4 characters. These are body size, number of proboscis hook rows, number of hooks per row, and length of the largest anterior 2-4 hooks. Male and female cystacanths of P. rancoensis are 2.10-3.33 mm long having an ovoid proboscis with 14 rows of 6-7 hooks per row, with the largest anterior 2-4 hooks being 105-110 micrometers long; the anterior trunk has many small spines in 70-80 concentric rings, each with 50-60 spines around them; hook roots are simple, directed posteriorly, about as long as the blades anteriorly with unremarkable anterior manubria; the cephalic ganglion are in mid-receptacle just anterior to the level of the anterior trunk; the lemnisci are long and slender; the testes are in the anterior trunk, posterior trunk, or one in each; the primordia of 2 tubular cement glands are evident; strong bundles of fibers link the anterior and posterior trunk; and the posterior trunk has a corrugated surface cuticula. Molecular analysis (COI and 18S) sequences coincided with the morphology and support its taxonomy. The phylogenetic profile revealed that P. rancoensis n. sp. fell into the Profilicollis clade. Both sequences showed low genetic variation, and three different haplotypes were found. The new species was more closely related to P. botulus (Van Cleave, 1916) Witenberg, 1932 than to other Profilicollis species.


Title: Révision du concept de Profilicollis Meyer, 1931 avec la description de Profilicollis rancoensis n. sp. (Acanthocephala, Polymorphidae) du crabe d'eau douce Aegla abtao Schmitt, 1942 (Decapoda, Anomura) au Chili, avec une clé des espèces congénères. Abstract: Profilicollis rancoensis n. sp. est la dixième espèce de Profilicollis Meyer, 1931 qui comprend neuf autres espèces principalement connues de crabes décapodes marins et d'oiseaux de rivage. Les cystacanthes de P. rancoensis sont décrits chez le crabe d'eau douce dominant Aegla abtao dans le lac Ranco, au Chili et se distinguent morphologiquement des cystacanthes des neuf autres espèces sur la base d'une combinaison de quatre caractères. Il s'agit de la taille du corps, du nombre de rangées de crochets du proboscis, du nombre de crochets par rangée et de la longueur des 2 à 4 crochets antérieurs les plus grands. Les cystacanthes mâles et femelles de P. rancoensis mesurent de 2,10 à 3,33 mm de long et ont une trompe ovoïde avec 14 rangées de 6 à 7 crochets par rangée, les 2 à 4 crochets antérieurs les plus grands mesurant 105 à 110 micromètres de long ; le tronc antérieur a de nombreuses petites épines en 70-80 anneaux concentriques chacun avec 50-60 épines ; les racines des crochets sont simples, dirigées vers l'arrière, à peu près aussi longues que les lames vers l'avant avec une manubrie antérieure sans particularité ; les ganglions céphaliques sont au milieu du réceptacle juste en avant du niveau du tronc antérieur ; les lemnisques sont longs et minces ; les testicules sont dans le tronc antérieur, le tronc postérieur ou un dans chacun ; les ébauches des 2 glandes cémentaires tubulaires sont évidentes ; de solides faisceaux de fibres relient le tronc antérieur et postérieur ; le tronc postérieur a une cuticule à surface ondulée. Les séquences d'analyse moléculaire (COI et 18S) coïncidaient avec la morphologie et confirmaient sa taxonomie. Le profil phylogénétique a révélé que P. rancoensis n. sp. appartient au clade Profilicollis. Les deux séquences ont montré une faible variation génétique et trois haplotypes différents ont été trouvés. La nouvelle espèce était plus proche de P. botulus (Van Cleave, 1916) Witenberg, 1932 que des autres espèces de Profilicollis.


Asunto(s)
Acantocéfalos , Anomuros , Helmintiasis Animal , Animales , Femenino , Masculino , Filogenia , Chile , Lagos
3.
Green Chem ; 25(2): 746-754, 2023 Jan 21.
Artículo en Inglés | MEDLINE | ID: mdl-37637778

RESUMEN

Both metal-catalyzed and organocatalytic transfer hydrogenation reactions are widely employed for the reduction of C=O and C=N bonds. However, selective transfer hydrogenation reactions of C=C bonds remain challenging. Therefore, the chemoselective transfer hydrogenation of olefins under mild conditions and in the absence of metal catalysts, using readily available and inexpensive reducing agents (i.e. primary and secondary alcohols), will mark a significant advancement towards the development of green transfer hydrogenation strategies. Described herein is an unconventional catalyst-free transfer hydrogenation reaction of activated alkenes using isopropanol as an eco-friendly reductant and solvent. The reaction gives convenient synthetic access to a wide range of substituted malonic acid half oxyesters (SMAHOs) in moderate to good yields. Mechanistic investigations point towards an unprecedented hydrogen bond-assisted transfer hydrogenation process.

4.
Acta Crystallogr C Struct Chem ; 79(Pt 4): 158-163, 2023 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-36946886

RESUMEN

An asymmetric bis(silyl) niobocene hydride complex, namely, bis(η5-cyclopentadienyl)(fluorodimethylsilyl)hydrido(iododimethylsilyl)niobium, [Nb(C5H5)2(C2H6FSi)(C2H6ISi)H] or Cp2NbH(SiIMe2)(SiFMe2), has been studied to determine the effect of the silyl ligand on the position of the hydride attached to the Nb atom. It has been shown that when a Group 17 atom is substituted onto one of the silyl ligands, there is a greater interaction between the hydride and this ligand, as demonstrated by a shorter Si...H distance. In the present work, we have investigated the effect when the silyl ligands are substituted by different Group 17 atoms. We present here the structure and DFT calculations of Cp2NbH(SiIMe2)(SiFMe2), showing that the position of the hydride is located between the two silyl ligands. The results from our investigation show that the hydride is closer to the silyl ligand that is substituted by fluorine.

5.
Parasite ; 29: 9, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35191831

RESUMEN

The morphology of cystacanths and adults of Profilicollis altmani (Perry, 1942) Van Cleave, 1947 (Polymorphidae) were studied from the Pacific mole crab Emerita analoga (Stimpson) (Crustacea, Hippidae) and Belcher's gull Larus belcheri (Vigors) (Aves, Laridae), respectively, in Peru. Comparative morphometrics with accounts of other populations of P. altmani from elsewhere off the Pacific and Atlantic coasts of North and South America revealed marked intraspecific population variations. We report scanning electron micrographs (SEM) of new features, not before noted or captured in line drawings by earlier observers. We further present microscope images that reveal internal details not previously reported or possible to see with SEM. Energy dispersive X-ray analysis (EDXA) revealed unusual patterns in the chemistry of proboscis hooks especially the high sulfur and diminished phosphorous and calcium in hook tips and low sulfur and high levels of phosphorous and calcium at mid hooks. The size and shape of all hooks of the cystacanths are reported for the first time. Histopathological studies in L. belcheri from Peru are also included. Cystacanths of P. altmani from California were also analyzed for molecular patterns and compared with other sequences reported from other locations. The molecular data and the analysis of our new sequences of cytochrome oxidase I (COI) showed that haplotypes of P. altmani had low genetic variation; the species is not geographically structured, and within its clade no monophyletic group is formed.


TITLE: Évaluation comparative de la morphologie de Profilicollis altmani (Acanthocephala, Polymorphidae) de crustacés et d'oiseaux de rivage au Pérou, en particulier l'analyse élémentaire des crochet (EDXA), l'imagerie SEM, l'histopathologie et le profil moléculaire. ABSTRACT: La morphologie des cystacanthes et des adultes de Profilicollis altmani (Perry, 1942) Van Cleave, 1947 (Polymorphidae) a été étudiée, respectivement, à partir du crustacé Emerita analoga (Stimpson) (Crustacea, Hippidae) et du Goéland Siméon Larus belcheri (Vigors) (Aves, Laridae), au Pérou. La morphométrie comparative avec des données d'autres populations de P. altmani d'autres localités au large des côtes du Pacifique et de l'Atlantique de l'Amérique du Nord et du Sud a révélé des variations intraspécifiques marquées des populations. Nous rapportons des nouvelles observations de microscopie électronique à balayage, non notées auparavant ou non capturées dans des dessins au trait par des observateurs antérieurs. Nous présentons en outre des images au microscope qui révèlent des détails internes qui n'ont pas été signalés auparavant ni possibles à voir avec MET. L'analyse aux rayons X à dispersion d'énergie (EDXA) a révélé des modèles inhabituels dans la chimie des crochets de la trompe, en particulier la teneur élevée en soufre et une diminution du phosphore et du calcium dans les pointes des crochets et des niveaux faibles en soufre et en phosphore et en calcium au milieu des crochets. La taille et la forme de tous les crochets des cystacanthes sont décrites pour la première fois. Des études histopathologiques sur L. belcheri du Pérou sont également incluses. Les cystacanthes de P. altmani de Californie ont également été analysés pour les modèles moléculaires et comparés à d'autres séquences rapportées d'autres endroits. Les données moléculaires et l'analyse de nos nouvelles séquences de cytochrome oxydase I (COI) ont montré que les haplotypes de P. altmani avaient une faible variation génétique. L'espèce n'est pas structurée géographiquement, et au sein de son clade aucun groupe monophylétique n'est formé.


Asunto(s)
Acantocéfalos , Anomuros , Helmintiasis Animal , Animales , Aves , Electrones , Perú , Rayos X
6.
Acta Parasitol ; 67(1): 369-379, 2022 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-34618302

RESUMEN

PURPOSE: The molecular profile of specimens of Mediorhynchus gallinarum (Bhalero, 1937) collected from chickens, Gallus gallus L. in Indonesia was analysed. The aim of this study was to assess the phylogenetic position of species of Mediorhynchus within the order Giganthorhynchida. METHODS: We used one mitochondrial gene (cytochrome oxidase 1) and one nuclear gene (18S ribosomal RNA) to infer phylogenetic relationships of class Archiacanthocephala. RESULTS: The COI and 18S rDNA genes sequences showed that M. gallinarum had low genetic variation and that this species is sister to Mediorhynchus africanus Amin, Evans, Heckmann, El-Naggar, 2013. The phylogenetic relationships of the Class Archiacanthocephala showed that it is not resolved but, however, were mostly congruent using both genes. A review of host-parasite life cycles and geographic distributions of Archiacanthocephala indicates that mainly small mammals and birds are definitive hosts, while termites, cockroaches, and millipedes are intermediate hosts. CONCLUSIONS: While the intermediate hosts have wide geographic distributions, the narrow distribution of the definitive hosts limit the access of archiacanthocephalans to a wider range of prospective hosts. Additional analyses, to increase taxonomic and character sampling will improve the development of a robust phylogeny and provide more stable classification. The results presented here contribute to better understanding of the ecological and evolutionary relationships that allow the host-parasite co-existence within the class Archiacanthocephala.


Asunto(s)
Acantocéfalos , Pollos , Acantocéfalos/genética , Animales , ADN Ribosómico/genética , Estadios del Ciclo de Vida , Mamíferos , Filogenia , Estudios Prospectivos , ARN Ribosómico 18S/genética
7.
J Parasitol ; 107(4): 547-553, 2021 07 01.
Artículo en Inglés | MEDLINE | ID: mdl-34270759

RESUMEN

The scarce information on the helminth fauna in otariids from the Southeastern Pacific comes mainly from stranded individuals or killed for that purpose. In this study, we compared the abundance and composition of enteroparasitic assemblages of Otaria flavescens using coprological techniques. Three sampling localities from north to south spanning 2,200 km off the Chilean coast were considered (Iquique, Viña del Mar, and Talcahuano). In all, 60 fecal samples were collected, and eggs belonging to 5 taxa were found in 91.6% of the samples. They were the anisakid nematodes Contracaecum and Pseudoterranova, the cestode Adenocephalus (syn. Diphyllobothrium), the trematode Ogmogaster, and the acanthocephalan Corynosoma. Samples from southern Chile (Talcahuano) showed the highest prevalence. Adenocephalus eggs had the highest prevalence and abundance in Iquique and Talcahuano, whereas Ogmogaster was the less prevalent and abundant in all sampling localities. Corynosoma eggs had similar prevalence and abundance among sampling localities, and Pseudoterranova eggs were absent in Iquique and with median prevalence values in Viña del Mar and Talcahuano. Thus, the composition of parasite egg assemblages was different between sampling localities. These differences between sampling localities may help to explain differential records of some zoonotic parasitoses such as pseudoterranovosis and diphyllobothriosis in Peru and Chile, where consumption of raw or marinated fish (ceviche) is common. For example, the lower diversity of parasite egg assemblages in the northern Chilean coast may be due to the absence or lower abundance of first intermediate/paratenic hosts of Pseudoterranova.


Asunto(s)
Infecciones por Ascaridida/veterinaria , Ascaridoidea/aislamiento & purificación , Heces/parasitología , Parasitosis Intestinales/veterinaria , Leones Marinos/parasitología , Zoonosis/parasitología , Animales , Infecciones por Ascaridida/epidemiología , Infecciones por Ascaridida/parasitología , Ascaridoidea/clasificación , Chile , Femenino , Parasitosis Intestinales/epidemiología , Parasitosis Intestinales/parasitología , Óvulo/clasificación , Océano Pacífico , Perú , Factores de Riesgo , Zoonosis/epidemiología
8.
Parasite ; 26: 73, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31855174

RESUMEN

Heterosentis holospinus Amin, Heckmann & Ha, 2011 (Arhythmacanthidae) was first described from the striped eel catfish, Plotosus lineatus (Plotosidae) in Halong Bay, Vietnam. New morphological information, scanning electron microscope images, molecular analysis, and Energy Dispersive X-ray analysis (EDXA) of hooks of specimens of H. holospinus from a new collection from the common ponyfish, Leiognathus equulus (Leiognathidae), in Quang Binh, Gulf of Tonkin, Vietnam are reported here for the first time. Additional details of the anterior trunk cone, proboscis hooks, wholly spined trunk, duck-bill-like spines with micropores, and micropore distribution, are described. The unique metal composition of hooks (EDXA) demonstrated a considerably higher level of calcium and phosphorus but lower level of sulfur at the hook basal arch than at the hook tip and edge. An analysis of our new sequences of cytochrome oxidase 1 (COI) showed that H. holospinus had low genetic variation and two haplotypes.


TITLE: Mise à jour morphologique et caractérisation moléculaire d'Heterosentis holospinus Amin, Heckmann & Ha, 2011 (Acanthocephala, Arhythmacanthidae) de l'Océan Pacifique au large du Vietnam. ABSTRACT: Heterosentis holospinus Amin, Heckmann & Ha, 2011 (Arhythmacanthidae) a été décrit pour la première fois chez le poisson-chat Plotosus lineatus (Plotosidae) dans la baie d'Halong, au Vietnam. Des nouvelles informations morphologiques, des images au microscope électronique à balayage, une analyse moléculaire et une analyse par rayons X à dispersion d'énergie (EDXA) des crochets de spécimens d'H. holospinus provenant d'une nouvelle récolte de Leiognathus equulus (Leiognathidae), à Quang Binh, golfe du Tonkin, Vietnam sont données pour la première fois. Des détails supplémentaires sur le cône antérieur du tronc, les crochets du proboscis, le tronc entièrement épineux, les épines en forme de bec de canard avec des micropores et la distribution des micropores sont décrits. La composition métallique unique des crochets (EDXA) a démontré une teneur en calcium et en phosphore considérablement plus élevée, mais une teneur en soufre plus faible au niveau de l'arcade basale du crochet qu'à la pointe et au bord du crochet. Une analyse de nos nouvelles séquences de cytochrome oxydase 1 (COI) a montré qu'H. holospinus présentait une faible variation génétique et deux haplotypes.


Asunto(s)
Acantocéfalos/anatomía & histología , Acantocéfalos/clasificación , Peces/parasitología , Helmintiasis Animal/parasitología , Animales , Complejo I de Transporte de Electrón/genética , Femenino , Enfermedades de los Peces/parasitología , Variación Genética , Haplotipos , Masculino , Microscopía Electrónica de Rastreo , Océano Pacífico , Vietnam
9.
Zootaxa ; 4555(2): 296-300, 2019 Feb 12.
Artículo en Inglés | MEDLINE | ID: mdl-30790968

RESUMEN

During almost two centuries, two available specific epithets have competed for the southern sea lions of the genus Otaria Péron, 1816 (Fig. 1), which is classically regarded as monotypic (but see below). The species distributes more or less continuously along the Atlantic coast from southern Brazil south to Cape Horn and along the Pacific from northern Peru to the west South American Pacific coast . While some researchers have argued that the correct name for this species is Phoca flavescens Shaw, 1800 (e.g., Cabrera, 1940, Rice, 1977; Rodriguez Bastida, 1993; Teta et al., 2018), others have used P. byronia de Blainville, 1820 (e.g., Allen, 1905; Hamilton, 1934; King, 1978, Oliva, 1988; Berta Churchill, 2012). This controversy originates from the fact that the diagnosis of the type of flavescens, the oldest epithet and as such the one that has priority, would not match the phenotypic features of the genus Otaria. This view, which favors the usage of byronia for populations of southern sea lions, was strongly defended by Oliva (1988:768), who argued that "…(1) the total length of the holotype [of flavescens]; (2) the size of the external ear; and (3) the color and length of the specimen's fur do not correspond to any developmental stage of the species." However, Rodríguez and Bastida (1993:378) discussed these same features reaching a very different conclusion, by indicating that "Shaw's holotype, collected in the Strait of Magellan, could only have been a newborn pup of Otaria or Arctocephalus australis; its body size (circa 62 cm) could correspond to either species, but the uniform yellowish color is found exclusively in some molted pups of the Southern sea lion. Ear length, though not matching well with the described body length, lies within the recorded range of Otaria, but outside that for Arctocephalus australis."


Asunto(s)
Lobos Marinos , Leones Marinos , Animales , Brasil , Perú
10.
J Parasitol ; 105(1): 19-24, 2019 02.
Artículo en Inglés | MEDLINE | ID: mdl-30807722

RESUMEN

The relationship between a parasite and its host will have an energy cost for the host at some point; however, this basic hypothesis has seldom been evaluated. Using Emerita analoga as a model species, we investigated the aerobic metabolism, ammonia excretion rate, and locomotor performance patterns of crabs both uninfected and infected with the acanthocephalan Profilicollis altmani. Our results show that infected Emerita had a lower metabolic rate compared to uninfected ones. Whether or not this decrease is a result of the pathology of the parasite infection or due to manipulation of the host by the parasite is still unknown. We discuss the importance of using anaerobic and aerobic metabolism and more-complex scenarios in order to understand the effects on host fitness and not only on the immediate response of the host.


Asunto(s)
Acantocéfalos/fisiología , Anomuros/metabolismo , Anomuros/parasitología , Amoníaco/metabolismo , Animales , Metabolismo Basal , Locomoción , Consumo de Oxígeno
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