The effect of hypoxia on locomotor performance and behaviour during escape in Liza aurata
Escape performance was investigated in the golden grey mullet Liza aurata exposed to various levels of oxygen: >85 (i.e. normoxia), 50, 20 and 10 % air saturation. Since the golden grey mullet performed aquatic surface respiration when air saturation approached 15–10 %, escape performance was tes...
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Published in | Journal of fish biology Vol. 67; no. 6; pp. 1711 - 1729 |
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Main Authors | , , |
Format | Journal Article |
Language | English |
Published |
Oxford, UK; Malden, USA
Blackwell Publishing Ltd/Inc
01.12.2005
Blackwell |
Subjects | |
Online Access | Get full text |
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Summary: | Escape performance was investigated in the golden grey mullet Liza aurata exposed to various levels of oxygen: >85 (i.e. normoxia), 50, 20 and 10 % air saturation. Since the golden grey mullet performed aquatic surface respiration when air saturation approached 15–10 %, escape performance was tested at 10 % air saturation with and without access to the surface (10 % S and 10 % C, respectively). Various locomotor and behavioural variables were measured, such as cumulative distance, maximum swimming speed, acceleration, responsiveness (per cent of responding fish), response latency and directionality. Golden grey mullet showed a decrease in responsiveness when the oxygen level was reduced to 10 % air saturation, whether the surface access was obstructed or not. Hypoxia did not have any effect on the response latency. Cumulative distance and maximum swimming speed over a fixed time were significantly different between normoxic conditions and 10 % C, while no differences were found in maximum acceleration. While the fish's ‘C‐bend’ was mainly directed away from the stimulus in normoxia, the proportion of away and towards ‘C‐bend’ was random when the oxygen was ≤20 % air saturation. This suggested an impairment of the left‐right discrimination at the initiation of the fast start. Hypoxia affected golden grey mullet escape performance mainly through an impairment of responsiveness and directionality, while locomotor performance was affected only in severe hypoxia when the surface was obstructed. The study showed that, in addition to forcing the fish to the surface as shown by previous studies, hypoxia may also reduce fish elusiveness facing a predator by directly impairing its escape performance. |
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Bibliography: | ark:/67375/WNG-B1TN9XV0-0 ArticleID:JFB884 istex:DCDEFBD40D9A5D1BA99FA23C3F1C4E2789964B44 ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 0022-1112 1095-8649 |
DOI: | 10.1111/j.1095-8649.2005.00884.x |