Spore production by Lithophyllum incrustans (Corallinales, Rhodophyta) in the British Isles

Abstract

Spore production in Lithophyllum incrustans, a rock-encrusting coralline red alga, was studied at 12 sites around the coast of Britain. Two types of spore are produced from asexual plants, bispores and tetraspores. The percentage of sexual plants in populations increases from north to south of the country and is strongly correlated with tetraspore production. A study of two populations over the course of one year revealed a seasonality in spore production, with plants being fertile during the winter months. Sexual plants are also fertile over the winter months.