The finding of Reticulocaulis mucosissimus in the Canary Islands represents the
first record in the Atlantic Ocean of Reticulocaulis, a marine red algal genus very rarely
reported and previously known only from the central Pacific (Hawaii) and the northwestern
Indian Ocean (Oman and Yemen). The vegetative and reproductive morphology of a
female gametophyte from La Palma (Canary Islands) is described in detail. The Canarian
plant exhibits the distinctive characters of R. mucosissimus, although the range of
morphological variation is extended for certain features like the occurrence of sinusoidal
apices, the early appearance of both periaxial cells, and the slightly longer carpogonial
branches. The infrequent sublittoral occurrence of ephemeral gametophytes and
undersampling of subtidal habitats can explain the disjunct distribution presently exhibited
by R. mucosissimus.
