FROND REGROWTH FROM BASAL DISK IN IRIDAEA-LAMINARIOIDES (RHODOPHYTA, GIGARTINALES) AT MEHUIN, SOUTHERN CHILE

Red algae of the family Gigartinaceae, including the genus Iridaea, have recently become of commercial importance as a primary source of carrageenans in the phycocolloid industry. This has led to excessive harvesting without any management plan. In southern Chile, I. laminarioides Bory has been of considerable interest not just because of its commercial value but also because of the interest in it for biological research. This study describes the formation of the erect frond from the crustose basal disc. This process allows survival of the population and maintains its competitive dominance in the rocky intertidal zone. Experimental pruning evaluated the optimum extent and frequency of pruning. Frond formation is a continuous process exhibiting a seasonal pattern; however, no significant differences in frond regrowth were found in pruning carried out at different seasons. Pruning frequency appeared to be a limiting factor affecting the regenerative ability of the basal disc. There was no evidence of any differences between the isomorphic phases in response to pruning. In all cases reproductive stages were reached after 6 mo.