Differences in the early stages of development of gametophytes and tetrasporophytes of Chondracanthus chamissoi (CAg) Kutzing from Puerto Aldea, northern Chile
No Thumbnail Available
Date
1996
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
Gametophytes of Chondracanthus chamissoi are more abundant in the field than tetrasporophytes. This differential phase ratio is well known in the literature for other members of the Gigartinaceae and has been explained as the result of either stochastic events or differential reproductive or physiological capacities between the phases. The comparison of both phases of Chondracanthus chamissoi in their early stages of development under laboratory conditions were summarised. Despite the higher biomass of reproductive tetrasporophytes recorded in summer (the seasonal maxima), significantly more carpospores are released per gram than tetraspores. During the following processes of settlement and germination, tetraspores show higher average values mainly due to their persistence in time. These differences tend to disappear in winter when the capacity of spores to develop normally appears to be lower. On the other hand, sporophytic growth rates are higher than gametophytic growth rates for most conditions of day length, light intensity and temperature. With no other external factors considered, the higher abundance of gametophytes in the field appears to be a result of the higher capacities of tetraspores to settle and germinate after an extended period of time suspended in the water column.
Description
Keywords
phase ratio, Chondracanthus chamissoi, spore settlement, spore germination, tetrasporophytes, gametophytes, developmental stages, spore release, spore suspension