Description of two new species of Ochtodes (Rhodophyta: Gigartinales) from Caribbean Mexico on the basis of morphological and molecular evidence

The species diversity of the red algal genus Ochtodes from Caribbean Mexico is reconsidered after a new collection in this region. A combined analysis of plastid rbcL sequences together with detailed morphological studies has confirmed the presence of two undescribed species in addition to Ochtodes secundiramea. Ochtodes akumalensis sp. nov. has abundant spiny branches, especially on the main axis, and robust cystocarps densely aggregate at the branch tips. In contrast, Ochtodes maguachaveziae sp. nov. lacks spiny branches and gland cells, and bears scattered cystocarps near the branch apices. Both species develop cruciately to obliquely divided zonate tetrasporangia. The molecular analysis showed that O. maguachaveziae and O. akumalensis represent separate taxonomic entities with a 1.8% sequence divergence between them. The description of two new species of Ochtodes from Caribbean Mexico suggest that our knowledge of the regional diversity of this genus is still incomplete.