Mucilage sheaths of spores of red algae

Abstract
If newly released spores of red algae are placed in a suspension of Indian ink in sea water, a clear halo of mucilaginous material will be seen. A similar mucilage cover is also a well-known feature with certain phytoplankton organisms, in which cells of spiny appearance (e.g. freshwater desmids) assume a spherical form in Indian ink when the mucilage cover is also observed (Lund, 1959). The attachment of red algal spores is a process in which mucilage clearly plays some part (Suto, 1950; Nakazawa, 1958; Matsumoto, 1959; Boney, 1966; Linskens, 1966; Moorjani & Jones, 1972; Charters, Neushul & Coon, 1972; Chamberlain & Evans, 1973). Studies on the sinking rate and dispersal of red algal spores have been described (Suto, 1950; Boney, 1965, 1966; Coon, Neushul & Charters, 1972). There appears to be little information on the sizes of the spore mucilage sheaths, and on their likely significance in the planktonic phase of the spore's existence immediately after release. The present work gives the results of an investigation of the spore mucilage of fourteen species of red algae.