Scaling relationships, individual variation and the influence of temperature on maximum swimming speed in early settled stages of the turbotScophthalmus maximus
✍ Scribed by S. Gibson; I. A. Johnston
- Publisher
- Springer-Verlag
- Year
- 1995
- Tongue
- English
- Weight
- 822 KB
- Volume
- 121
- Category
- Article
- ISSN
- 0025-3162
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✦ Synopsis
Escape-swimming speeds (Umax) were studied in settled turbot (Scophthalmus maximus L.) reared at 18 ~ Metamorphosis was complete at 4.0 cm total length (TL). Uma x scaled in proportion to TL ~ in fish of 0,88 to 8.00 cm TL at 18 ~ The scaling relationship for Um,• was similar for temperatures between 13 and 23 ~ and could be fitted by the model: Umax =28.4+10.9(temp-13/+ \ / 10.3 TL. Urea x was temperature-dependent, with a Qlo of 1.77 over the temperature range studied. Analysis of covariance showed that U~nax for farmed turbot was 14% lower than for wild fish filmed within 2 wk of capture; 3 mo after capture the average differences in escape performance were no longer significant, which suggests that the lower escape speeds of farmed fish are due to acclimation effects and not genetic stock differences. In order to assess the individual variability of Umax, 18 wild juvenile turbot [TL = 6.2 + 0.4 cm (Week 1) to 7.5 + 0.5 cm (Week 17); means + SD] were maintained in individual containers at 18 ~ Um~ ~ was determined weekly for 6 wk, standardised for fish length using the scaling relationship Umax = 1.46 TL ~ and individuals were ranked in order of performance. Temperature was reduced after 6 wk to 13 ~ resulting in a significant decline in Lima x from 104.0 _ 14.4 to 87.8 _ 12.5 cm s -1 (means + SD). After 3 wk at 13 ~ Urn, x had increased to a level not significantly different from that at 18 ~ Kendall's coefficient of concordance showed that repeatability of ranking of the experimental Urea x of individuals was maintained over a 13 wk period and through temperature change. The results demonstrate that escape-swimming speeds in juvenile turbot are repeatable, individually variable, and can be modified in response to temperature acclimation.