Dra. Tellier, Florence

Phyllophorella was recently described from two localities on the central coast of Peru (12°S), based on the endemic species Phyllophora (Ph.) peruviana. The genus currently accommodates three species, Phyllophorella (P.) peruviana, P. humboldtiana and P. limaensis. Recent field surveys for Phyllophorella on the central coast of Peru led to the discovery of collections outside the originally reported ranges. Morphological, anatomical, and genetic characterization of the specimens confirms range extensions for P. peruviana to 9° S and 15° S, and P. humboldtiana to 12° S and 15° S. A combined phylogenetic analysis of rbcL and COI-5P gene sequences supports the taxonomic status of these two species and reasserts the genus as monophyletic. Anatomically, the two species differ in nemathecial structure. Phyllophorella peruviana displays dome-shaped and well-defined circular nemathecia, whereas in P. humboldtiana they are irregular and diffuse in form. Mature cystocarps were observed for the first time in Phyllophorella, in P. humboldtiana from Lima and Ica, Peru. Phyllophorella, as well as the other genera classified to the family Phyllophoraceae, have a procarpic sexual system, with a carpogonial branch of three cells; the cystocarp develops a thickened cortex, is immersed in the medulla, and lacks a pericarp and an ostiole. This study demonstrates that field work, together with morphological, developmental, and genetic analyses, are useful methods for improving our understanding of seaweed distributions and systematics.

The red seaweed Chondracanthus chamissoi shows high morphological variability. Initially, three species were identified based on the width of the main axis of their blades. Later, all of them were included in a single species with two morphological groups. Recently, quantitative studies demonstrated the existence of two forms in C. chamissoi: f. lessonii and f. chauvinii. It was also shown that these two forms occur in sympatry, growing side by side. These forms were not associated with either a life cycle phase or the sex of the blades. This study aimed to determine whether the two forms could represent different species. We evaluated the forms' taxonomic position using COI and rbcL markers, including samples from three localities in southern Chile. All specimens shared a single rbcL haplotype, whereas the two COI haplotypes differed by four base pairs and were present in blades of both forms and life cycle phases. The two morphological types correspond to intraspecific forms. This species is of commercial importance, and its main market is aimed at human consumption with a marked preference for f. lessonii.