Diversity of the genus Sheathia (Batrachospermales, Rhodophyta) in northeast India and east Nepal

Necchi, Orlando Jr.,West, John A.,Ganesan, E.K.,Yasmin, Farishta,Rai, Shiva Kumar,Rossignolo, Natalia L. The Korean Society of Phycology 2019 ALGAE Vol.34 No.4

Freshwater red algae of the order Batrachospermales are poorly studied in India and Nepal, especially on a molecular basis. During a survey in northeast India and east Nepal, six populations of the genus Sheathia were found and analyzed using molecular and morphological evidence. Phylogenetic analyses based on the rbcL gene sequences grouped all populations in a large clade including our S. arcuata specimens and others from several regions. Sheathia arcuata represents a species complex with a high sequence divergence and several smaller clades. Samples from India and Nepal were grouped in three distinct clades with high support and representing new cryptic species: a clade formed by two samples from India, which was named Sheathia assamica sp. nov.; one sample from India and one from Nepal formed another clade, named Sheathia indonepalensis sp. nov.; two samples from Nepal grouped with sequences from Hawaii and Indonesia (only 'Chantransia' stages) and gametophytes from Taiwan, named Sheathia dispersa sp. nov. Morphological characters of the specimens from these three species overlap one another and with the general circumscription of S. arcuata, which lacks the heterocortication (presence of bulbous cells in the cortical filaments) present in other species of the genus Sheathia. Although the region sampled is relatively restricted, the genetic diversity among specimens of these three groups was high and not closely related in the phylogenetic relationship with the other clades of S. arcuata. These data corroborate information from other groups of organisms (e.g., land and aquatic plants) that indicates this region (Eastern Himalaya) as a hotspot of biodiversity.

Thorea indica sp. nov. (Thoreales, Rhodophyta) from Uttar Pradesh, India

Necchi, Orlando Jr,Paiano, Monica O.,West, John A.,Ganesan, E. K.,Goer, Susan Loiseaux-de The Korean Society of Phycology 2015 ALGAE Vol.30 No.4

Thorea indica sp. nov. is described from the Sai River, Uttar Pradesh, India (26°39′00.7″ N, 80°47′38.3″ E). Its classification is based on molecular sequences of the plastid-encoded RuBisCO large-subunit gene, rbcL and the barcode region of the mitochondrial encoded cytochrome c oxidase subunit 1, cox1, and morphological data. The sequence analyses confirm a new species of Thorea. The cox1 barcode sequence had 90.4-90.8% identity with Thorea sp. from Australia and Thorea hispida from Hawaii and China. Based on rbcL sequences the Indian specimen was positioned in a major clade with high support (>95 bootstrap and 0.95 posterior probability) containing two other species: T. okadae from Japan and T. hispida from the continental USA, Hawaii, the UK, and China. The divergences among these sequences were T. indica vs. T. okadae (2.8%) and T. indica vs. T. hispida (2.9-3.4%). The comparison of morphological characters of Thorea from India was not conclusive due to the inadequate descriptions in previous reports: most specimens reported as T. hispida fit within the circumscription of T. indica as described here. The previous report of T. siamensis from the Sai River is incorrect and the specimens fit within our description of T. indica. Thorea indica and T. okadae can be distinguished by minor morphometric characters and sexuality (dioecious vs. monoecious).

Thorea indica sp. nov. (Thoreales, Rhodophyta) from Uttar Pradesh, India

Orlando Necchi Jr.,Monica O. Paiano,John A. west,E. K. Ganesan,Susan Loiseaux de Goër 한국조류학회I 2015 ALGAE Vol.30 No.4

Thorea indica sp. nov. is described from the Sai River, Uttar Pradesh, India (26°39′00.7″ N, 80°47′38.3″ E). Its classification is based on molecular sequences of the plastid-encoded RuBisCO large-subunit gene, rbcL and the barcode region of the mitochondrial encoded cytochrome c oxidase subunit 1, cox1, and morphological data. The sequence analyses confirm a new species of Thorea. The cox1 barcode sequence had 90.4-90.8% identity with Thorea sp. from Australia and Thorea hispida from Hawaii and China. Based on rbcL sequences the Indian specimen was positioned in a major clade with high support (>95 bootstrap and 0.95 posterior probability) containing two other species: T. okadae from Japan and T. hispida from the continental USA, Hawaii, the UK, and China. The divergences among these sequences were T. indica vs. T. okadae (2.8%) and T. indica vs. T. hispida (2.9-3.4%). The comparison of morphological characters of Thorea from India was not conclusive due to the inadequate descriptions in previous reports: most specimens reported as T. hispida fit within the circumscription of T. indica as described here. The previous report of T. siamensis from the Sai River is incorrect and the specimens fit within our description of T. indica. Thorea indica and T. okadae can be distinguished by minor morphometric characters and sexuality (dioecious vs. monoecious).

Diversity of freshwater red algae at Khao Luang National Park, southern Thailand

Chankaew, W.,Sakset, A.,Chankaew, S.,Ganesan, E.K.,Necchi, Orlando Jr.,West, John A. The Korean Society of Phycology 2019 ALGAE Vol.34 No.1

Freshwater red algal diversity and the relationship with water conditions in 22 stream segments in the area around Khao Luang National Park, Nakhon Si Thammarat province, southern Thailand, were studied during a period of twelve months (May 2014 to April 2015). Sixteen species of freshwater red algae, belonging to eight genera (Audouinella, Balliopsis, Batrachospermum, Caloglossa, Compsopogon, Kumanoa, Sirodotia, and Thorea) were identified, which were all reported earlier for the country. Thorea clavata (Thoreaceae) was the most common species occurring in eight stream segments. Caloglossa beccarii sensu lato (Delesseriaceae) and Sirodotia huillensis Skuja (Batrachospermaceae) had the highest percent cover with up to 40% and 20% per stream segment, respectively. The water quality showed most sites to be unpolluted or ultra-oligotrophic to oligotrophic. Canonical Correspondence Analysis revealed some trends in occurrence of individual species with stream environmental variables: Batrachospermum sp.with strong current velocity; Kumanoa hirosei with high turbidity, total dissolved solid and alkalinity; Caloglossa beccarii with high conductivity; Kumanoa tabagatenensis with high ammonia-nitrogen and Thorea siamensis with high calcium and magnesium. In view of the scarce studies on the stream ecology of freshwater red algae in Philippines and neighbouring countries, it is expected that the data presented here would be helpful in more critical further studies in south-east Asia in general.

Diversity of freshwater red algae at Khao Luang National Park, southern Thailand

W. Chankaew,A. Sakset,A. Sakset,E. K. Ganesan,Orlando Necchi Jr.,John A. West 한국조류학회I 2019 ALGAE Vol.34 No.1

Freshwater red algal diversity and the relationship with water conditions in 22 stream segments in the area aroundKhao Luang National Park, Nakhon Si Thammarat province, southern Thailand, were studied during a period of twelvemonths (May 2014 to April 2015). Sixteen species of freshwater red algae, belonging to eight genera (Audouinella, Balliopsis,Batrachospermum, Caloglossa, Compsopogon, Kumanoa, Sirodotia, and Thorea) were identified, which were allreported earlier for the country. Thorea clavata (Thoreaceae) was the most common species occurring in eight streamsegments. Caloglossa beccarii sensu lato (Delesseriaceae) and Sirodotia huillensis Skuja (Batrachospermaceae) had thehighest percent cover with up to 40% and 20% per stream segment, respectively. The water quality showed most sitesto be unpolluted or ultra-oligotrophic to oligotrophic. Canonical Correspondence Analysis revealed some trends inoccurrence of individual species with stream environmental variables: Batrachospermum sp. with strong current velocity;Kumanoa hirosei with high turbidity, total dissolved solid and alkalinity; Caloglossa beccarii with high conductivity;Kumanoa tabagatenensis with high ammonia-nitrogen and Thorea siamensis with high calcium and magnesium. Inview of the scarce studies on the stream ecology of freshwater red algae in Philippines and neighbouring countries, itis expected that the data presented here would be helpful in more critical further studies in south-east Asia in general.