Proposals to recognize Petalonia tenella comb. nov. and to resurrect Hapterophycus canaliculatus (Scytosiphonaceae, Phaeophyceae)

The brown algal family Scytosiphonaceae has recently received considerable attention resulting in the description of several new genera and species. However, members of the genus Scytosiphon and Petalonia remain polyphyletic. By integrating multi-gene phylogenetic data (mitochondrial cox3 and plastid psaA and rbcL genes) with their known morpho-anatomies and life histories, we herein resurrect Hapterophycus canaliculatus, currently considered a member of genus Scytosiphon, and transfer Scytosiphon tenellus to the genus Petalonia

Taxonomy of the genus Sargassum (Fucales, Phaeophyceae) from Alabat Island, Quezon, Northeastern Philippines

Taxonomic observations on some Sargassum species in Alabat Island, Quezon are presented. These are based on collections made on the spot during an ecological survey on the Sargassum-dominated seaweed communities in the locality. Gross morphological characteristics of the species such as the type of holdfast, shape and nature of its branches, vesicles, leaves, nature and distribution of cryptostomata, and nature and form of receptacles were used to discriminate the different morphotypes. Free-hand sections of receptacles were made to ascertain the sex of the plant. Different morphotypes were identif ied up to species level when possible. Eight morphotypes were distinct, six of which were recognized, namely, Sargassum crassifolium J. Agardh, S. cristaefolium C. Agardh, S. kushimotense Yendo, S. gracillimum Reinbold, S. myriocystum J. Agardh, and S. polycystum C.A. Agardh. The two other remaining materials were unidentif ied and are described here in detail