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1.
Braz. j. biol ; 82: e232805, 2022. tab, graf
Artigo em Inglês | LILACS-Express | LILACS | ID: biblio-1153457

RESUMO

Abstract One of the biological indicators most used to determine the health of a fluvial ecosystem are the benthic macroinvertebrates. The presence of recurrent species in a wide gradient of latitudes, dominates the biogeographic pattern of the benthic macroinvertebrates in Chilean fresh waters, nevertheless the knowledge on the communitarian ecology of these in the Chilean rivers continues to be scarce. Null models became a powerful statistical tool for describing the ecological mechanisms that drive the structure of an ecological community and the underlying patterns of diversity. The objective of this study was to determine the community structure of benthic invertebrates in the Allipén River by describing their composition, richness and abundance of species through richness models and null models based on presence/absence. The results reveal a high family richness and low diversity, three phyla, five classes, 11 orders and 28 families were identified in the study area during the four seasons of the year. The Arthropoda phylum was the most representative in abundance and richness. Regarding to richness, Trichoptera (7 families) and Diptera (6 families) followed by Ephemeroptera (3 families) were the orders that showed the greatest diversity of families, however, a low diversity with a H'≤ 1.5 nit was registered in the study area. We demonstrated through the null models, the randomization in the species associations corresponding to the three analyzed sites. The information provided here contributes to the understanding of the ecological patterns of the invertebrate communities in the Allipén River, establishing the basis for more complex ecological studies.


Resumo Um dos indicadores biológicos mais utilizados para determinar a saúde de um ecossistema fluvial são os macroinvertebrados bentônicos. A presença de espécies recorrentes em um amplo gradiente de latitudes domina o padrão biogeográfico dos macroinvertebrados bentônicos nas águas doces do Chile; no entanto, o conhecimento sobre a ecologia comunitária destes nos rios chilenos continua escasso. Os modelos nulos se tornaram uma poderosa ferramenta estatística para descrever os mecanismos ecológicos que orientam a estrutura de uma comunidade ecológica e os padrões subjacentes da diversidade. O objetivo deste estudo foi determinar a estrutura da comunidade de invertebrados bentônicos no rio Allipén, descrevendo sua composição, riqueza e abundância de espécies através de modelos de riqueza e modelos nulos baseados na presença / ausência. Os resultados revelam alta riqueza de espécies e baixa diversidade, sendo identificados três filos, cinco classes, 11 ordens e 28 famílias na área de estudo durante as quatro estações do ano. O filo de Arthropoda foi o mais representativo em abundância e riqueza. Em relação à riqueza, Trichoptera (7) e Diptera (6) seguidos por Ephemeroptera (3) foram as ordens que mostraram a maior diversidade de famílias, no entanto, uma baixa diversidade com H'≤ 1,5 nit foi registrada na área de estudo. Demonstramos através dos modelos nulos, a randomização nas associações de espécies correspondentes aos três locais analisados. As informações aqui fornecidas contribuem para a compreensão dos padrões ecológicos das comunidades de invertebrados no rio Allipén, estabelecendo a base para estudos ecológicos mais complexos.

2.
Braz. j. biol ; 81(3): 642-649, July-Sept. 2021. tab, graf
Artigo em Inglês | LILACS-Express | LILACS | ID: biblio-1153397

RESUMO

Abstract The zooplankton communities often exhibit daily vertical migrations to avoid natural ultraviolet radiation and/or fish predation. However there is no information on this topic in Chilean North Patagonian lakes up to date. Therefore, this study deals with a first characterization of plankton crustacean daily vertical migration in two temperate, oligotrophic lakes (Villarrica and Panguipulli lakes, 39°S) in Southern Chile. Zooplankton were collected at different depths intervals (0-10m, 10-20 m, 20-30m, 30-40m) at early morning, middle day, evening and night in the studied site. The results revealed that zooplankton species (Daphnia pulex, Ceriodaphnia dubia, Neobosmina chilensis, Mesocyclops araucanus, and Tropocyclops prasinus) are abundant in surface zones at night, early morning and evening, whereas at middle day the zooplankton abundances are high at deep zones. The results agree with observations for Argentinean and North American lakes where these daily migration patterns in crustacean zooplankton species were reported due mainly natural ultraviolet radiation exposure, whereas for northern hemisphere lakes the vertical migration is due to combined effect of natural ultraviolet radiation and fish predation exposure.


Resumo As comunidades zooplanctônicas frequentemente exibem migrações verticais diárias para evitar a radiação ultravioleta natural e/ou a predação de peixes. No entanto, não há informações sobre esse tema em lagos chilenos no norte da Patagônia até a presente data. Portanto, este estudo trata de uma primeira caracterização da migração vertical diária de crustáceo planctônico em dois lagos temperados e oligotróficos (lagos Villarrica e Panguipulli, 39º S) no sul do Chile. O zooplâncton foi coletado em diferentes profundidades (0-10 m, 10-20 m, 20-30 m e 30-40 m) no início da manhã, ao meio-dia, à tarde e à noite no local estudado. Os resultados revelaram que as espécies de zooplâncton (Daphnia pulex, Ceriodaphnia dubia, Neobosmina chilensis, Mesocyclops araucanus e Tropocyclops prasinus) são abundantes nas zonas de superfície à noite, de manhã cedo e à tarde, enquanto, ao meio-dia, as abundâncias do zooplâncton são altas nas zonas de profundidade. Os resultados expostos corroboram as observações para outros lagos argentinos e da América do Norte, onde foram reportados esses padrões de migração diária em espécies crustáceas de zooplâncton por causa, principalmente, da exposição à radiação ultravioleta natural, enquanto, para lagos do hemisfério norte, a migração vertical se dá em razão do efeito combinado da radiação ultravioleta natural e exposição à predação.

3.
Braz. j. biol ; 81(3): 797-805, July-Sept. 2021. tab
Artigo em Inglês | LILACS-Express | LILACS | ID: biblio-1153410

RESUMO

Abstract The Patagonian blenny (Eleginops maclovinus) is species endemic to South America with physiological characteristics that would facilitate its incorporation into Chilean aquaculture. However, there is currently no specific artificial food that can be used to raise E. maclovinus. In light of this problem, this study describes the proximal composition and fatty acid profile of the crab Hemigrapsus crenulatus, one of the main foods of E. maclovinus. The purpose of the study is to serve as basic information for the development of a specific artificial diet for juveniles of this fish species. The proximal analysis of the complete body of H. crenulatus indicates that it is mainly composed of ash (35.9%), proteins (32.2%), glucides (19.8%) and minor lipids (3.6%). The fatty acid profile is 40.7% PUFAs, 29.7% MUFAs and 29.5% SAFAs, and the most abundant acids are Eicosapentaenoic (18.8%), Oleic (6.8%) and Palmitic (16.6%), respectively. H. crenulatus has highest level of proteins, lipids and PUFAs among the species of the Brachyura infraorder.


Resumo O "blenny da patagônia" (Eleginops maclovinus) é uma espécie endêmica da América do Sul, com características fisiológicas que facilitariam sua incorporação na aquicultura chilena. No entanto, atualmente não há alimento artificial específico que possa ser usado para criar E. maclovinus. Diante desse problema, este estudo descreve a composição proximal e o perfil de ácidos graxos do caranguejo Hemigrapsus crenulatus, um dos principais alimentos de E. maclovinus. O objetivo do estudo é servir como informação básica para o desenvolvimento de uma dieta artificial específica para espécies juvenis desse peixe. A análise proximal do corpo completo de H. crenulatus indica que ele é composto, principalmente, de cinzas (35,9%), proteínas (32,2%), glicídios (19,8%) e lipídios menores (3,6%). O perfil de ácidos graxos é 40,7% PUFA, 29,7% MUFA e 29,5% SAFA, e os ácidos mais abundantes são eicosapentaenoico (18,8%), oleico (6,8%) e palmítico (16,6%), respectivamente. H. crenulatus possui o mais alto nível de proteínas, lipídios e PUFAs entre as espécies da infraordem de Brachyura.

4.
Braz. j. biol ; 81(2): 335-342, Jan.-May 2021. graf
Artigo em Inglês | LILACS-Express | LILACS | ID: biblio-1153364

RESUMO

Abstract The species of Pugilina cochlidium (Linnaeus, 1758) and P. erecta (Vermeij & Raben, 2009) has been studied in the present study. The female can be differentiated from the male by the absence of the cephalic penis and a complicated genital aparatus visible through the mantle skirt in both the sexes. In other aspects of the external features of female are quite to males. In both species the digestive system was similar with few differences in structure between each other. It consists of buccal mass, proboscis, salivary glands, accessory salivary glands, oesophagus, stomach, intestine, rectum and anus. The nervous system in both P. cochlidium and P. erecta is constituted by six ganglia which forms the circumoesophgeal ganglionic ring. Among the neogastropods there is a similarity in the organization of the reproductive systems. The female reproductive system is more complicated than that of male. The sexes are separated in these two species. The gross morphology of the reproductive system of P. cochlidium and P. erecta was almost similar. The present study aims to describe the digestive system, nervous system and reproductive system of two gastropods species P. cochlidium and P. erecta.


Resumo As espécies de Pugilina cochlidium (Linnaeus, 1758) e P. erecta (Vermeij & Raben, 2009) foram tomadas no presente estudo. A fêmea pode ser diferenciada do macho pela ausência do pênis cefálico e um complicado complexo genital visível através da saia do manto em ambos os sexos. Em outros aspectos das características externas da fêmea são bastante semelhantes aos dos machos. Em ambas as espécies, o sistema digestivo era semelhante, com poucas diferenças de estrutura entre si. Consiste em massa bucal, probóscide, glândulas salivares, glândulas salivares acessórias, esôfago, estômago, intestino, reto e ânus. O sistema nervoso em P. cochlidium e P. erecta é constituído por seis gânglios que formam um anel ganglionar circunoesofágico. Entre os neogastrópodes, há uma semelhança na organização dos sistemas reprodutivos. O sistema reprodutivo feminino é mais complicado que o masculino. Os sexos são separados nessas duas espécies. A morfologia macroscópica do sistema reprodutivo de P. cochlidium e P. erecta foi quase similar. O presente estudo tem como objetivo descrever o sistema digestivo, sistema nervoso e sistema reprodutivo de duas espécies, P. cochlidium e P. erecta.

5.
Braz J Biol ; 82: e232805, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33787712

RESUMO

One of the biological indicators most used to determine the health of a fluvial ecosystem are the benthic macroinvertebrates. The presence of recurrent species in a wide gradient of latitudes, dominates the biogeographic pattern of the benthic macroinvertebrates in Chilean fresh waters, nevertheless the knowledge on the communitarian ecology of these in the Chilean rivers continues to be scarce. Null models became a powerful statistical tool for describing the ecological mechanisms that drive the structure of an ecological community and the underlying patterns of diversity. The objective of this study was to determine the community structure of benthic invertebrates in the Allipén River by describing their composition, richness and abundance of species through richness models and null models based on presence/absence. The results reveal a high family richness and low diversity, three phyla, five classes, 11 orders and 28 families were identified in the study area during the four seasons of the year. The Arthropoda phylum was the most representative in abundance and richness. Regarding to richness, Trichoptera (7 families) and Diptera (6 families) followed by Ephemeroptera (3 families) were the orders that showed the greatest diversity of families, however, a low diversity with a H'≤ 1.5 nit was registered in the study area. We demonstrated through the null models, the randomization in the species associations corresponding to the three analyzed sites. The information provided here contributes to the understanding of the ecological patterns of the invertebrate communities in the Allipén River, establishing the basis for more complex ecological studies.


Assuntos
Ecossistema , Rios , Animais , Chile , Monitoramento Ambiental , Água Doce , Humanos , Invertebrados
6.
Braz J Biol ; 2020 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-33146252

RESUMO

The species of Pugilina cochlidium (Linnaeus, 1758) and P. erecta (Vermeij & Raben, 2009) has been studied in the present study. The female can be differentiated from the male by the absence of the cephalic penis and a complicated genital aparatus visible through the mantle skirt in both the sexes. In other aspects of the external features of female are quite to males. In both species the digestive system was similar with few differences in structure between each other. It consists of buccal mass, proboscis, salivary glands, accessory salivary glands, oesophagus, stomach, intestine, rectum and anus. The nervous system in both P. cochlidium and P. erecta is constituted by six ganglia which forms the circumoesophgeal ganglionic ring. Among the neogastropods there is a similarity in the organization of the reproductive systems. The female reproductive system is more complicated than that of male. The sexes are separated in these two species. The gross morphology of the reproductive system of P. cochlidium and P. erecta was almost similar. The present study aims to describe the digestive system, nervous system and reproductive system of two gastropods species P. cochlidium and P. erecta.

7.
Braz J Biol ; 2020 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-33111927

RESUMO

The zooplankton communities often exhibit daily vertical migrations to avoid natural ultraviolet radiation and/or fish predation. However there is no information on this topic in Chilean North Patagonian lakes up to date. Therefore, this study deals with a first characterization of plankton crustacean daily vertical migration in two temperate, oligotrophic lakes (Villarrica and Panguipulli lakes, 39°S) in Southern Chile. Zooplankton were collected at different depths intervals (0-10m, 10-20 m, 20-30m, 30-40m) at early morning, middle day, evening and night in the studied site. The results revealed that zooplankton species (Daphnia pulex, Ceriodaphnia dubia, Neobosmina chilensis, Mesocyclops araucanus, and Tropocyclops prasinus) are abundant in surface zones at night, early morning and evening, whereas at middle day the zooplankton abundances are high at deep zones. The results agree with observations for Argentinean and North American lakes where these daily migration patterns in crustacean zooplankton species were reported due mainly natural ultraviolet radiation exposure, whereas for northern hemisphere lakes the vertical migration is due to combined effect of natural ultraviolet radiation and fish predation exposure.

8.
Braz J Biol ; 81(3): 797-805, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33605301

RESUMO

The Patagonian blenny (Eleginops maclovinus) is species endemic to South America with physiological characteristics that would facilitate its incorporation into Chilean aquaculture. However, there is currently no specific artificial food that can be used to raise E. maclovinus. In light of this problem, this study describes the proximal composition and fatty acid profile of the crab Hemigrapsus crenulatus, one of the main foods of E. maclovinus. The purpose of the study is to serve as basic information for the development of a specific artificial diet for juveniles of this fish species. The proximal analysis of the complete body of H. crenulatus indicates that it is mainly composed of ash (35.9%), proteins (32.2%), glucides (19.8%) and minor lipids (3.6%). The fatty acid profile is 40.7% PUFAs, 29.7% MUFAs and 29.5% SAFAs, and the most abundant acids are Eicosapentaenoic (18.8%), Oleic (6.8%) and Palmitic (16.6%), respectively. H. crenulatus has highest level of proteins, lipids and PUFAs among the species of the Brachyura infraorder.


Assuntos
Braquiúros , Perciformes , Animais , Aquicultura , Chile , Ácidos Graxos
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