Identification of ‘articuliths’ in a unique algal bed formation from Brazil and description of Jania cabista sp. nov. (Corallinales, Rhodophyta)

Abstract

ABSTRACT A unique algal bed formation, composed largely of free-living geniculate coralline algae (articuliths), was recorded within the subtidal zone of Arraial do Cabo Bay, Brazil. The importance of these articuliths was shown by previous ecological surveys, which, using morpho-anatomical analyses, identified these algal specimens as belonging to Amphiroa beauvoisii, Jania adhaerens and J. capillacea. Cryptic diversity was recently found in Brazilian corallines and prompted the reassessment of the species diversity of the Arraial do Cabo Bay algal bed. Here we identified the species of geniculate coralline algae commonly associated with the subtidal beds of Arraial do Cabo Bay using a combination of molecular (psbA) and morpho-anatomical analyses, and compared them to closely related species described for Brazil and elsewhere. Two species belonging to the genera Amphiroa and Jania were identified as the major components of these algal beds. Our analyses suggest that these specimens belong to Amphiroa cf. exilis and to a new species of Jania, Jania cabista sp. nov.