The culture of benthic marine algae in the laboratory and the field

Abstract

1. Growth and development of algae from spores has been observed in the laboratory (Menai Bridge) and under field conditions at Ravenspoint (West coast of Anglesey). Attempts were made to culture all main components of the sub-littoral flora. Spore material was obtained from spores allowed to settle onto plastic slides in the laboratory sea water system and from spores settled on slides stationed in the field. 2. Attention was given to the summer annual species and, in particular, to those members of the Nemalionales (Rhodophyceae) which have incompletely known life histories. In these plants, the tetrasporic phase during which reduction division normally takes place, has so far been undetected in the field. The plants are represented by the cystocarpic phase of the life cycle only. 3. The fate of the carpospores of these species were of particular interest. The spores of the annual species were cultivated under a number of regimes of irradiation and temperature. Sporelings from laboratory culture were transferred to the field in November, 2 months after settlement. Both in laboratory and field, the form of development of the cultures were similar until May of the following year. Then the field cultures developed structures which may represent the tetrasporangia of the alternate phase. These structures failed to develop in the laboratory cultures after 3 years. 4. The results of these experiments illustrate that care must be taken in interpreting results of laboratory cultures of algae, in particular in regard to their life histories. © 1970 Biologischen Anstalt Helgoland.