Diversity and phylogeny of the brown alga Lobophora (Dictyotales, Phaeophyceae) in Singapore

The brown macroalgal genus Lobophora (Phaeophyceae: Dictyotaceae) plays an ecologically significant role in many marine ecosystems, but their diversity and taxonomy remain poorly studied. Until 2012, six Lobophora species had been recognised globally based on morphological features. Yet, with more than 100 evolutionary taxonomic units characterised to date, it is now acknowledged that Lobophora comprises many cryptic species and its diversity was vastly underestimated. In light of a growing body of research integrating molecular and morphological data to delimit cryptic species, this study assessed the diversity and phylogeny of Lobophora in Singapore. A combination of molecular data and morphological observations were used to delimit and identify species from 33 specimens collected at eight sites in the southern islands of Singapore. The mitochondrial cox3 and chloroplast psbA genes were amplified and sequenced for phylogenetic analysis. Three formally described species, L. challengeriae, L. lamourouxii, L. pachyventera (comprising two morphotypes), as well as one undescribed putative species, Lobophora sp61, were recovered. These findings replace the record of the Atlantic species L. variegata in Singapore and suggest that there are more species to be discovered in the biodiverse region of Southeast Asia. Precise understanding of Lobophora diversity is critical for ongoing and future work on coral–macroalgal ecological relationships.

Phylogeny of Cystoseira Sensu Lato from SE Spain Suggests a Complex Colonization of the Mediterranean

Cystoseira is a relevant alga, which forms dense meadows on rocky substrates up to 100 meters deep. They are widely recognized as bioindicators for their restricted habitat (sub-coastal zone) and low tolerance to pollution. We have monitored Cystoseira sensu lato (sl) spp. in abrasion platforms in Cabo de Las Huertas (Alicante, SE Spain), a total of seven species. A cladogram has been constructed using fifteen phenotypic taxonomic relevant characters. We have also optimized Cystoseira DNA extraction and sequenced amplicons from mt23S, tRNA-Lys, and psbA genes of five Cystoseira sl species from Cabo de Las Huertas. Our phylogenetic supertree, built with these sequences, backs three clades in the genus. Rare species Treptacantha sauvageauana and Treptacantha algeriensis, sequenced for the first time, are included with T. elegans and the Atlantic species T. baccata and T. abies-marina in Cystoseira-VI or Cystoseira-II clades. Our data supports a complex colonization of Cystoseira (sl) spp. in the Mediterranean, perhaps involving Atlantic clades.

Batrachospermum qujingense (Batrachospermales, Rhodophyta), a new freshwater red algal species from Southwest China

Batrachospermum is a widely distributed genus in China. Nonetheless, many taxa recorded previously have no molecular data. In this study, a new species of Batrachospermum called Batrachospermum qujingense is described and illustrated from Qujing, Yunnan, Southwest China, based on morphological observations and a phylogenetic analysis. This species is distinguished morphologically from other species by dioecious thalli, straight carpogonial branches with 7–9 cells and stalked angled obovoid or inflated-clavate trichogynes. In addition, a phylogenetic analysis of the molecular data from the rbcL, COI-5P, and psbA genes indicated separation between the new species proposed in this study and other species in the genus Batrachospermum (4.0–5.3% for rbcL, 7.7%–10.6% for COI-5P, and 2.2–3.2% for psbA ). This is the first species of Batrachospermum reported in Yunnan and the third species of Batrachospermum with molecular data in China. The description of the new species and geographical distribution expands the diversity of freshwater red algae in China.