First report of Reticulocaulis mucosissimus (Naccariaceae, Rhodophyta) for the Atlantic Ocean

Abstract

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.