Hildenbrandia ramanaginai Khan

Ganesan, E. K., West, John A. & Jr, Orlando Necchi, 2018, A catalogue and bibliography of non-marine (freshwater and estuarine) Rhodophyta (red algae) of India, Phytotaxa 364 (1), pp. 1-48 : 10

Hildenbrandia ramanaginai Khan

Khan 1974, p. 238, figs 1– 6 (as H. “ramnaginaii ”)

Distribution in India: Uttarakhand (olive green encrusting lithophyte on limestones in the rapidly flowing Rispana River, near Dehra Dun, Feb., Mar.).

Notes: Hildenbrandia is more commonly distributed world-wide in the marine environments, with 16 currently recognized species ( Guiry & Guiry 2017). In freshwater, two species [ H. angolensis Welwitsch ex W. West et G. S. West and H. rivularis (Liebman) J. Agardh ] are known ( Kumano 2002, Necchi 2016). A third species, H. jogongshanensis , was described from China ( Nan et al. 2017a). Curiously, in contrast to some red algal taxa ( Bostrychia moritziana , Caloglossa ogasawaraensis , and Polysiphonia subtilissima ) treated as marine invaders ( Sheath & Vis 2015), which are adapted to live both in marine and freshwater environments, the same species of Hildenbrandia is not reported to occur both in salt and freshwaters. Ott (2009) corrected the species epithet from the original “ramanaginaii ” to “ ramanaginai ”, in accordance with the Botanical Nomeclatural Code (see however, Silva 2017; Guiry & Guiry 2017). H. ramnaginaii is endemic to India and is known only from the single original collection made about 40 years ago in northern India. However, some “ H. ramanaginaii ” images without a description of color and anatomy were provided by Baluswami (2009) based on a collection from Monkey Falls, near Coimbatore, Tamilnadu, South India. In contrast to the usually striking bright red or crimson color of the crusts in freshwaters ( Eloranta & Kwandrans 2007; Sherwood & Sheath 1999, 2000; West & Ganesan pers. obser. in a freshwater stream in eastern Venezuela), H. ramnaginai crusts are “olive green” in color ( Khan 1974). Ott (2009, p. 622) noted that the peculiar color of the Indian specimens in the following terms “If the placement of this alga in Hildenbrandia is valid, the reported color of “olive green” would represent the first species of Hildenbrandia not possessing carmine to rose-red color characteristic of the genus”. Asexual reproductive bodies like gemmae or stolons frequently reported in other species were also not observed in the Indian specimens. The Indian species warrants recollecting from the type locality and reinvestigation to clarify if it is Hildenbrandia using several methods (DAPI staining, TEM, DNA and pigment analyses) of Caisová & Kopecký (2008) who have shown that a ‘copper coloured’ crustose thallus first identified as the cyanobacterium Pleurocapsa cuprea Hansgirg from rocks in mountain streams of Austria and the Czech Republic is a eukaryotic red alga Hildenbrandia linked to H. rivularis . Sherwood & Sheath (2000, 2003) studied extensively the systematics, biogeography, multivariate morphometrics and the gene sequeces of rbc L and 18 S rRNA of both marine and freshwater representatives of Hildenbrandia of global populations from four continents. Their requests to examine the type specimen of the Indian species from six different herbaria in India (BHAV, BSD, BSIS, BURD, CAL, and DD) were unsuccessful and hence unavailable for comparative studies. Based on their studies of other species, the authors recognized two groups of species in Hildenbrandi a (i) north-American and Philippines and (ii) Europe and Canary Islands. Another poorly known Asiatic freshwater species is the Burmese H. arracana ( Zeller, 1873) .