Reproductive sensitivity to elevated water temperatures in female Atlantic salmon is heightened at certain stages of vitellogenesis
In order to compare the effects on reproductive performance of short-term or prolonged exposure to elevated temperatures during vitellogenesis, female Atlantic salmon Salmo salar were held at a water temperature of 22C for periods of 4 or 6 weeks during the austral summer and autumn. Plasma levels o...
| Published in: | Journal of Fish Biology |
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| Main Authors: | , , |
| Format: | Article in Journal/Newspaper |
| Language: | English |
| Published: |
Wiley-Blackwell Publishing Ltd
2007
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| Subjects: | |
| Online Access: | https://doi.org/10.1111/j.1095-8649.2006.01295.x http://ecite.utas.edu.au/49430 |
| Summary: | In order to compare the effects on reproductive performance of short-term or prolonged exposure to elevated temperatures during vitellogenesis, female Atlantic salmon Salmo salar were held at a water temperature of 22C for periods of 4 or 6 weeks during the austral summer and autumn. Plasma levels of 17-oestradiol (E2), testosterone (T) and vitellogenin (Vtg) were monitored and reproductive success was compared to that in groups of fish maintained at 14 or 22C for 12 weeks from mid-January. Significant endocrine effects were observed within as few as 3 days of the commencement of exposure to 22C, when plasma levels of E2 (c. 0.5 ng ml -1) and Vtg (c. 1.4 mg ml-1) were approximately half those observed in fish maintained at 14C (c. 1.0 ng ml-1 and 2.7 mg ml-1 respectively). The fertility and survival to the eyed stage of ova from fish held at 14C exceeded 85 and 70% respectively, whereas ova from fish held at 22C for 6 or 12 weeks exhibited significantly reduced fertility (<70 and <45% respectively) and survival (c. 40 and 13% respectively). In spite of significant endocrine effects at all stages, a 4 week exposure to 22C only generated significant reductions in egg fertility (<65%) and survival (c. 30%) when it occurred between mid-February and mid-March. Together, these data confirm that high temperature spikes can affect reproductive success as strongly as more prolonged exposures, and indicate that there is a critical period of reproductive sensitivity to elevated temperature in late February and early March in this stock of Atlantic salmon. 2007 The Fisheries Society of the British Isles. |
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