Codiophyllum mexicanum sp. nov. (Halymeniaceae, Rhodophyta), first record of a stalked red alga associated with sponges in the western Atlantic

Abstract

ABSTRACTThe species of the family Halymeniaceae are characterised by their multiaxial thallus and sexual reproduction, involving carpogonial branches and auxiliary cells borne in filamentous ampullae and tetrasporangia decussately or cruciately divided. Most species of the genera Thamnoclonium, Spongophloea, Codiophyllum and Carpopeltis belong to the group of red algae associated with sponges that, so far, have been recorded only in the Indian and Pacific Oceans. In a survey along the Campeche coast of Mexico, however, we found numerous specimens of a stalked red alga associated with a sponge. On the basis of molecular rbcL sequences and morphological features, these specimens proved to be a species of Codiophyllum. Given its independent phylogenetic position within the genus, morphological differences with C. flabelliforme and C. natalense (the other two known species), such as almost cylindrical, non-extended or flabellate axes, the lateral branching pattern, flattened specialised proliferations, and its geographic distribution, we described it as the new species C. mexicanum, the first stalked red alga associated with sponges described and recorded for the western Atlantic.