Reproductive strategies of Laurencia perforata (Bory) Montagne (Ceramiales, Rhodomelaceae) in the Canary Islands

Abstract

Laurencia perforata (Bory) Montagne was originally described from the Canary Islands. It is a red alga characterized by its creeping thallus, with arcuate sub-erect branches attached to the rocky substrate or to other branches by small terminal secondary holdfasts. The sequential development of the holdfasts and their ecological role in the asexual reproduction of the plant are described. After meeting another branch of the substrate, the tips of arcuate branches begin to develop rhizoidal proliferations. In later stages these proliferations form discoidal secondary holdfasts, from which new axes may arise. This vegetative propagation process is rather common in natural populations. In the present paper, tetrasporangia of L. perforata are described for the first time. Tetrasporangia occur in right-angle disposition and are cut off abaxially. These characteristics together with those of the cortical cells confirms earlier suggestions on the taxonomic position of this species in the subgenus Chondrophycus.