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Dissotichus eleginoides has a discontinuous circumpolar geographic distribution restricted to mountains and platforms, mainly in Subantarctic and Antarctic waters of the southern hemisphere, including the Southeast Pacific, Atlantic and Indian oceans and in areas surrounding the peninsular platforms of subantarctic islands. The aim of this work was to determine and characterize the gastrointestinal parasitic and microbial fauna of specimens of D. eleginoides captured in waters of the south-central zone of Chile. The magnitude of parasitism in D. eleginoides captured in waters of the south-central zone of Chile is variable, and the parasite richness is different from that reported in specimens from subantarctic environments. Next-generation sequencing (NGS) of the microbial community associated to intestine showed a high diversity, where Proteobacteria, Firmicutes, and Bacteriodetes were the dominant phyla. However, both parasitic and microbial structures can vary between fish from different geographic regions.
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An amendment to this paper has been published and can be accessed via a link at the top of the paper.
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Antarctic and Subantarctic lakes are unique ecosystems with relatively simple food webs, which are likely to be strongly affected by climate warming. While Antarctic freshwater invertebrates are adapted to extreme environmental conditions, little is known about the factors determining their current distribution and to what extent this is explained by biogeography or climate. We explored the distribution of freshwater crustaceans (one of the most abundant and diverse group of organisms in Antarctic and Subantarctic lakes) across four biogeographic provinces (Continental Antarctic, CA; Maritime Antarctic, MA; Subantarctic islands, SA; and Southern Cool Temperate, SCT) based on the literature, predicting that species distribution would be determined by biogeography, spatial autocorrelation among regions (in relation to dispersal) and climate. We found that variation in species composition was largely explained by the joint effect of spatial autocorrelation and climate, with little effect of biogeography - only regions within the SA province had a clearly distinct species composition. This highlights a plausible main influence of crustacean dispersal - mainly through migratory seabirds - and suggests that some regions will be more affected by climate warming than others, possibly in relation to the existence of nearby sources of colonists.
Assuntos
Crustáceos , Distribuição Animal , Animais , Regiões Antárticas , Clima , Crustáceos/fisiologia , Ecossistema , Lagos/análiseRESUMO
The Chilean Patagonia has numerous kinds of inland water ecosystems such as lakes, ponds, wetlands and rivers that have been poorly studied due to access difficulties. This study was carried out in Aysen region, in southern Chile, and it included different kinds of water bodies such as rivers, streams, ponds, lagoons and lakes distributed along an altitudinal gradient at 46° S. It was found a low species number, essentially cladocerans, copepods and amphipods. A null model was applied in order to determine the existence of regulator factors of species associations, and the results revealed that they are not random. The patterns would be influenced by geographical and limnological characteristics of the studied sites. Our results would agree with regional studies on habitat heterogeneity such as in Torres del Paine National Park and other zones in Tierra del Fuego island.
Assuntos
Altitude , Crustáceos/classificação , Ecossistema , Animais , Chile , Monitoramento AmbientalRESUMO
The Chilean Patagonia has numerous kinds of inland water ecosystems such as lakes, ponds, wetlands and rivers that have been poorly studied due to access difficulties. This study was carried out in Aysen region, in southern Chile, and it included different kinds of water bodies such as rivers, streams, ponds, lagoons and lakes distributed along an altitudinal gradient at 46° S. It was found a low species number, essentially cladocerans, copepods and amphipods. A null model was applied in order to determine the existence of regulator factors of species associations, and the results revealed that they are not random. The patterns would be influenced by geographical and limnological characteristics of the studied sites. Our results would agree with regional studies on habitat heterogeneity such as in Torres del Paine National Park and other zones in Tierra del Fuego island.
A Patagônia chilena apresenta numerosos tipos de ecossistemas aquáticos, como lagos, lagoas, pântanos e rios, os quais tem sido pouco estudados devido a dificuldades de acesso. Este estudo foi feito na região de Aysén, no sul do Chile, e inclui diferentes tipos de corpos d'água, tais como rios, córregos, lagos, lagoas e lagos distribuídos ao longo de um gradiente de altitude a 46° S. Constatou-se baixo número de espécies que inclui, essencialmente, cladóceros, copépodos e anfípodos. Um modelo nulo foi aplicado para determinar a existência de fatores reguladores das associações de espécies os resultados indicam que estes não são aleatórios. Os padrões poderiam ser influenciados pelas características geográficas e limnológicas do locais estudados. Os resultados expostos concordariam com estudos regionais sobre com habitats heterogeneidade como Torres del Paine Parque Nacional e outras zonas na ilha de Tierra del Fuego.
Assuntos
Animais , Altitude , Crustáceos/classificação , Ecossistema , Chile , Monitoramento AmbientalRESUMO
The Chilean Patagonia has numerous kinds of inland water ecosystems such as lakes, ponds, wetlands and rivers that have been poorly studied due to access difficulties. This study was carried out in Aysen region, in southern Chile, and it included different kinds of water bodies such as rivers, streams, ponds, lagoons and lakes distributed along an altitudinal gradient at 46° S. It was found a low species number, essentially cladocerans, copepods and amphipods. A null model was applied in order to determine the existence of regulator factors of species associations, and the results revealed that they are not random. The patterns would be influenced by geographical and limnological characteristics of the studied sites. Our results would agree with regional studies on habitat heterogeneity such as in Torres del Paine National Park and other zones in Tierra del Fuego island.(AU)
A Patagônia chilena apresenta numerosos tipos de ecossistemas aquáticos, como lagos, lagoas, pântanos e rios, os quais tem sido pouco estudados devido a dificuldades de acesso. Este estudo foi feito na região de Aysén, no sul do Chile, e inclui diferentes tipos de corpos d'água, tais como rios, córregos, lagos, lagoas e lagos distribuídos ao longo de um gradiente de altitude a 46° S. Constatou-se baixo número de espécies que inclui, essencialmente, cladóceros, copépodos e anfípodos. Um modelo nulo foi aplicado para determinar a existência de fatores reguladores das associações de espécies os resultados indicam que estes não são aleatórios. Os padrões poderiam ser influenciados pelas características geográficas e limnológicas do locais estudados. Os resultados expostos concordariam com estudos regionais sobre com habitats heterogeneidade como Torres del Paine Parque Nacional e outras zonas na ilha de Tierra del Fuego.(AU)
Assuntos
Animais , Altitude , Crustáceos/classificação , Ecossistema , Chile , Monitoramento AmbientalRESUMO
This paper describes the frequency and number of Sphyrion laevigatum in the skin of Genypterus blacodes, an important economic resource in Chile. The analysis of a spatial distribution model indicated that the parasites tended to cluster. Variations in the number of parasites per host could be described by a negative binomial distribution. The maximum number of parasites observed per host was two.
Assuntos
Copépodes/fisiologia , Doenças dos Peixes/parasitologia , Peixes/parasitologia , Animais , Distribuição BinomialRESUMO
This paper describes the frequency and number of Sphyrion laevigatum in the skin of Genypterus blacodes, an important economic resource in Chile. The analysis of a spatial distribution model indicated that the parasites tended to cluster. Variations in the number of parasites per host could be described by a negative binomial distribution. The maximum number of parasites observed per host was two.
Este artigo descreve a frequência e o número de Sphyrion laevigatum da pele de Genypterus blacodes, o qual é um importante recurso econômico no Chile. A análise baseada em modelos de distribuição espacial, demonstrou que os parasitos tendem a ficar agrupados. A variação numérica de parasitas por hospedeiro pode ser descrita por distribuição binomial negativa. O número máximo observado de parasitas por hospedeiro foi dois.
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Nematodes of the genus Anisakis have marine fishes as intermediate hosts. One of these hosts is Thyrsites atun, an important fishery resource in Chile between 38 and 41° S. This paper describes the frequency and number of Anisakis nematodes in the internal organs of Thyrsites atun. An analysis based on spatial distribution models showed that the parasites tend to be clustered. The variation in the number of parasites per host could be described by the negative binomial distribution. The maximum observed number of parasites was nine parasites per host. The environmental and zoonotic aspects of the study are also discussed.