Tribute to R. G. Boutilier: The effect of size on the physiological and behavioural responses of oscar, Astronotus ocellatus, to hypoxia
The physiological and behavioural responses of two size groups of oscar (Astronotus ocellatus) to hypoxia were studied. The physiological responses were tested by measuring ṀO2 during decreasing environmental oxygen tensions. Larger oscars were better able to maintain oxygen consumption during a dec...
| Autor principal: | Sloman, Katherine A. |
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| Outros Autores: | Wood, Chris M., Scott, Graham R., Wood, Sylvia, Kajimura, Makiko, Johannsson, Ora E., Almeida-Val, Vera Maria Fonseca, Val, Adalberto Luis |
| Grau: | Artigo |
| Idioma: | English |
| Publicado em: |
Journal of Experimental Biology
2020
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| Acesso em linha: |
https://repositorio.inpa.gov.br/handle/1/15049 |
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oai:repositorio:1-15049 |
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oai:repositorio:1-15049 Tribute to R. G. Boutilier: The effect of size on the physiological and behavioural responses of oscar, Astronotus ocellatus, to hypoxia Sloman, Katherine A. Wood, Chris M. Scott, Graham R. Wood, Sylvia Kajimura, Makiko Johannsson, Ora E. Almeida-Val, Vera Maria Fonseca Val, Adalberto Luis Oxygen Water Animals Behavior, Animals Body Size Cichlid Environment Histology Oxygen Consumption Physiology Animal Behavior, Animals Body Size Cichlids Environment Oxygen Oxygen Consumption Water Astronotus Astronotus Ocellatus The physiological and behavioural responses of two size groups of oscar (Astronotus ocellatus) to hypoxia were studied. The physiological responses were tested by measuring ṀO2 during decreasing environmental oxygen tensions. Larger oscars were better able to maintain oxygen consumption during a decrease in PO2, regulating routine ṀO2 to a significantly lower PO2 threshold (50 mmHg) than smaller oscars (70 mmHg). Previous studies have also demonstrated a longer survival time of large oscars exposed to extreme hypoxia, coupled with a greater anaerobic enzymatic capability. Large oscars began aquatic surface respiration (ASR) at the oxygen tension at which the first significant decrease in ṀO2 was seen (50 mmHg). Interestingly, smaller oscars postponed ASR to around 22 mmHg, well beyond the PO2 at which they switched from oxyregulation to oxyconformation. Additionally, when given the choice between an hypoxic environment containing aquatic macrophyte shelter and an open normoxic environment, small fish showed a greater preference for the hypoxic environment. Thus shelter from predators appears particularly important for juveniles, who may accept a greater physiological compromise in exchange for safety. In response to hypoxia without available shelter, larger fish reduced their level of activity (with the exception of aggressive encounters) to aid metabolic suppression whereas smaller oscars increased their activity, with the potential benefit of finding oxygen-rich areas. 2020-05-07T14:02:12Z 2020-05-07T14:02:12Z 2006 Artigo https://repositorio.inpa.gov.br/handle/1/15049 10.1242/jeb.02090 en Volume 209, Número 7, Pags. 1197-1205 Attribution-NonCommercial-NoDerivs 3.0 Brazil http://creativecommons.org/licenses/by-nc-nd/3.0/br/ application/pdf Journal of Experimental Biology |
| institution |
Instituto Nacional de Pesquisas da Amazônia - Repositório Institucional |
| collection |
INPA-RI |
| language |
English |
| topic |
Oxygen Water Animals Behavior, Animals Body Size Cichlid Environment Histology Oxygen Consumption Physiology Animal Behavior, Animals Body Size Cichlids Environment Oxygen Oxygen Consumption Water Astronotus Astronotus Ocellatus |
| spellingShingle |
Oxygen Water Animals Behavior, Animals Body Size Cichlid Environment Histology Oxygen Consumption Physiology Animal Behavior, Animals Body Size Cichlids Environment Oxygen Oxygen Consumption Water Astronotus Astronotus Ocellatus Sloman, Katherine A. Tribute to R. G. Boutilier: The effect of size on the physiological and behavioural responses of oscar, Astronotus ocellatus, to hypoxia |
| topic_facet |
Oxygen Water Animals Behavior, Animals Body Size Cichlid Environment Histology Oxygen Consumption Physiology Animal Behavior, Animals Body Size Cichlids Environment Oxygen Oxygen Consumption Water Astronotus Astronotus Ocellatus |
| description |
The physiological and behavioural responses of two size groups of oscar (Astronotus ocellatus) to hypoxia were studied. The physiological responses were tested by measuring ṀO2 during decreasing environmental oxygen tensions. Larger oscars were better able to maintain oxygen consumption during a decrease in PO2, regulating routine ṀO2 to a significantly lower PO2 threshold (50 mmHg) than smaller oscars (70 mmHg). Previous studies have also demonstrated a longer survival time of large oscars exposed to extreme hypoxia, coupled with a greater anaerobic enzymatic capability. Large oscars began aquatic surface respiration (ASR) at the oxygen tension at which the first significant decrease in ṀO2 was seen (50 mmHg). Interestingly, smaller oscars postponed ASR to around 22 mmHg, well beyond the PO2 at which they switched from oxyregulation to oxyconformation. Additionally, when given the choice between an hypoxic environment containing aquatic macrophyte shelter and an open normoxic environment, small fish showed a greater preference for the hypoxic environment. Thus shelter from predators appears particularly important for juveniles, who may accept a greater physiological compromise in exchange for safety. In response to hypoxia without available shelter, larger fish reduced their level of activity (with the exception of aggressive encounters) to aid metabolic suppression whereas smaller oscars increased their activity, with the potential benefit of finding oxygen-rich areas. |
| format |
Artigo |
| author |
Sloman, Katherine A. |
| author2 |
Wood, Chris M. Scott, Graham R. Wood, Sylvia Kajimura, Makiko Johannsson, Ora E. Almeida-Val, Vera Maria Fonseca Val, Adalberto Luis |
| author2Str |
Wood, Chris M. Scott, Graham R. Wood, Sylvia Kajimura, Makiko Johannsson, Ora E. Almeida-Val, Vera Maria Fonseca Val, Adalberto Luis |
| title |
Tribute to R. G. Boutilier: The effect of size on the physiological and behavioural responses of oscar, Astronotus ocellatus, to hypoxia |
| title_short |
Tribute to R. G. Boutilier: The effect of size on the physiological and behavioural responses of oscar, Astronotus ocellatus, to hypoxia |
| title_full |
Tribute to R. G. Boutilier: The effect of size on the physiological and behavioural responses of oscar, Astronotus ocellatus, to hypoxia |
| title_fullStr |
Tribute to R. G. Boutilier: The effect of size on the physiological and behavioural responses of oscar, Astronotus ocellatus, to hypoxia |
| title_full_unstemmed |
Tribute to R. G. Boutilier: The effect of size on the physiological and behavioural responses of oscar, Astronotus ocellatus, to hypoxia |
| title_sort |
tribute to r. g. boutilier: the effect of size on the physiological and behavioural responses of oscar, astronotus ocellatus, to hypoxia |
| publisher |
Journal of Experimental Biology |
| publishDate |
2020 |
| url |
https://repositorio.inpa.gov.br/handle/1/15049 |
| _version_ |
1787144321953169408 |
| score |
11.755432 |