GROWTH AND REPRODUCTIVE PHENOLOGY OF IRIDAEA CILIATA KÜTZING (RHODOPHYTA, GIGARTINALES) IN A SUBLITTORAL POPULATION

Abstract

Phenological and growth patterns of a subliltoral population of Iridaea ciliata (Rhodophyta, Gigartinales) in Punta de Parra, Concepción Bay, are described, for a study period of twenty months. A seasonal growth is documented with density, length and biomass máximum in summer autumm, and mínimum in winter. This cycle was correlated with several environmental factors, indicating that the amount of biomass between December and March was related to solar radiation and photoperiod. However the low quantity of biomass was associated with sand movement from and toward the beds of /. ciliata and with tides (water movement). Seasonal growth of /. ciliata was shown not to be affected by temperature or salinity. Throughout the year a smalc proportion of tetrasporic plants was observed. In the formation of new blades, regeneration from the vegetative activity of basal dises was remarkable, as was the burial in sand for 3 to 4 months each year.