CONTROL OF GAMETE RELEASE IN FUCOID ALGAE: SENSING HYDRODYNAMIC CONDITIONS VIA CARBON ACQUISITION
- ISSN: 0012-9658
- DOI: 10.1890/0012-9658(1998)079[1725:COGRIF]2.0.CO;2
We investigated the environmental factors providing signals for gamete release in fucoid algae, with a particular focus on the inhibitory effect of water motion. The release of gametes by Fucus distichus occurred in still water under high light and was associated with the depletion of dissolved inorganic carbon (DIC) in tide pools isolated from the ocean during daytime low tides. Diurnal patterns of gamete release that lasted for 2–3 d, as in natural populations, were found in receptacles cultured in a 12 h light:12 h dark photoperiod under calm conditions or in a simulated tidal regime. Constant light disrupted the diurnal component of release, however, suggesting that an endogenous circadian periodicity was absent. The effects of increased [DIC] on cultured receptacles under calm conditions were similar to the inhibitory effects of high water motion; both conditions reduced release in several species from both tide pool and intertidal habitats. Bicarbonate concentration, rather than carbon dioxide, or c...