Morphological and molecular characterization ofUlva chaugulii sp. nov., U. lactuca and U. ohnoi (Ulvophyceae, Chlorophyta) from India M ud a ssa r A n iso d d in K a z i', M o n ic a G. K a v a l e '* a n d V e e r e n d r a

The biodiversity assessment of different taxa of the genus Caulerpa is of interest from the context of morphological plasticity, invasive potential of some species and biotechnological and pharmacological applications. The present study investigated the identification and molecular phylogeny of different species of Caulerpa occurring along the Indian coast inferred from tufA, rbcL, 18S rDNA and ITS rDNA nucleotide sequences. Molecular data confirmed the identification of 10 distinct Caulerpa species: C. veravalensis, C. verticillata, C. racemosa, C. microphysa, C. taxifolia, C. sertularioides, C. scalpelliformis, C. serrulata, C. peltata and C. mexicana. All datasets significantly supported the sister relationship between C. veravalensis and C. racemosa var. cylindracea. It was also concluded from the results that the specimen identified previously as C. microphysa and C. lentillifera could not be considered as separate species. The molecular data revealed the presence of multiple lineages for C. racemosa which can be resolved into separate species. All four markers were used to ascertain their utility for DNA barcoding. The tufA gene proved a better marker with monophyletic association as the main criteria for identification at the species level. The results also support the use of 18S rDNA insertion sequences to delineate the Caulerpa species through character-based barcoding. The ITS rDNA (5.8S-ITS2) phylogenetic analysis also served as another supporting tool. Further, more sequences from additional Caulerpa specimens will need to be analysed in order to support the role of these two markers (ITS rDNA and 18S insertion sequence) in identification of Caulerpa species. The present study revealed the phylogeny of Caulerpa as complete as possible using the currently available data, which is the first comprehensive report illustrating the molecular phylogeny and barcoding of the genus Caulerpa from Indian waters.

Seaweeds are a renewable marine resources and have not yet received considerable attention in the field of taxonomy in India as compared to their terrestrial counterparts, essentially due to the lack of awareness of their economic potential. Although the recent inventory from the Indian region documented the presence of approximately 865 seaweed taxa, of which only a few are taxonomically well characterized, more precise information still awaits with respect to microscopic and molecular examinations of many. Thus far, in terms of spatial extent, probably only a few of the total hospitable seaweed habitats have been explored, and large portions, including island territories and subtidal waters, remain virtually untouched. Surveying those may lead to the reporting of several taxa new to science. Furthermore, more focused efforts are required to understand the endemic and endangered taxa which have high conservation implications. Considering the unprecedented pressures seaweeds are facing, including coastal pollution and human-induced global warming, it is critical to reinforce our knowledge of seaweed biodiversity. In the present communication, we intended to address the status of seaweed biodiversity in India along with the gaps, challenges, and opportunities.

No abstract