Aquatic Sciences Meeting, Albuquerque 2001
| SS15 Biomechanics: Making the Connection Between Physics and Biology at the Organismal Level (Disciplinary Connections) |
| Date: Wednesday, February 14, 2001, Time: 9:45:00 AM |
| Location: Mesilla |
| Serrao, E, A, Center for Marine Sciences, UCTRA, Univ Algarve, Gambelas, 8000-810 Faro, Portugal, eserrao@ualg.pt |
| Pearson, G, A, Center for Marine Sciences, UCTRA, Univ Algarve, Gambelas, 8000-810 Faro, Portugal, gpearson@ualg.pt |
| SWEPT AWAY? RELEASING GAMETES UNDER OPTIMAL HYDRODYNAMIC CONDITIONS FOR SUCCESSFUL FERTILIZATION. |
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| Simulations of external fertilization on exposed shores predict that large proportions of eggs are never fertilized due to gamete dilution by water motion. This prediction is based on the assumption that gametes are released under hydrodynamic conditions that quickly dilute gametes. We examined 1) whether fucoid algae might achieve high fertilization by restricting gamete release to calm intervals, and 2) mechanisms that might mediate this response. Peaks of gamete release by subtidal populations of Fucus vesiculosus occur only on calm days, and Fucus distichus living in tide pools releases gametes during day-time low tides, when water motion is minimal. Experiments confirmed that water motion inhibits gamete release by several species of fucoid algae. Photosynthesis is required for gamete release and manipulation of dissolved inorganic carbon (DIC) overcame the effects of water motion, indicating that gamete release is triggered by DIC depletion in the unstirred boundary layer during periods of low water motion in the light. In conclusion, species from exposed habitats can synchronize gamete release with environmental conditions that favor successful fertilization. |
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