Species diversity and molecular phylogeny of non-geniculate coralline algae (Corallinophycidae, Rhodophyta) from Taoyuan algal reefs in northern Taiwan, including Crustaphytum gen. nov. and three new species

Abstract

In Taiwan the algal reefs in Taoyuan County are the largest, composed of recent and fossil non-geniculate coralline algae. However, their diversity and phylogenetics in the region have never been documented. In this study, we analyzed the phylogenetic relationships of the non-geniculate coralline algae species collected from Taoyuan algal reefs and related non-geniculate species from other places in Taiwan and around the world based on psbA and SSU sequences. The molecular analyses revealed that at least 12 non-geniculate coralline species belonging in six evolutionary clades (Harveylithon, Lithophyllum, Pneophyllum, Crustaphytum gen. nov., and Phymatolithon, Sporolithon) occur in Taoyuan algal reefs. Eleven of these species do not match any described species and one (Lithophyllum margaritae) is a new record for the marine flora of Taiwan. We also describe a new genus (Crustaphytum gen. nov.) and three new non-geniculate coralline species (Crustaphytum pacificum sp. nov., Harveylithon rosea sp. nov., and Phymatolithon margoundulatus sp. nov.) for the most dominant and commonly seen species revealed by the molecular analyses. Among the latter three species, P. margoundulatus is only found in Taoyuan County and is the most dominant species there, comprising over 30% of the total cover, whereas C. pacificum has the widest distribution in the western Pacific Ocean (Taiwan and New Caledonia). Harveylithon rosea is a common species occurring in both algal reefs and rocky shores in the northern Taiwan. The other undescribed CCA species will be published when more specimens with reproductive structures are collected.