1 2014] BHAKTA & ADHIKARY : ALGAL DIVERSITY IN THE STREAMS AND WATERFALLS N E L U M B O 56 : 1- 47, 2014 Date of publication: 30th December, 2014 © Botanical Survey of India, 2014 ALGAL DIVERSITY IN THE STREAMS AND WATERFALLS OF EASTERN AND NORTH-EASTERN REGION OF INDIA S. BHAKTA AND S.P. ADHIKARY Department of Biotechnology, Visva-Bharati, Institute of Science, Santiniketan 731235, West Bengal ABSTRACT Two hundred fourteen species of algae were recorded from 12 mountain streams of Odisha and 21 streams and waterfalls of the Eastern Himalayan region covering West Bengal, Sikkim, Arunachal Pradesh, Nagaland and Mizoram. Of these Chlorophyta (39), Cyanophyta (31), Heterokontophyta (24) and Euglenophyta (3) were specifically from the streams in Odisha whereas Cyanophyta (43), Chlorophyta (34) and Bacillariophyceae (26) were from the streams and waterfalls of the eastern Himalayan region. The diversity of algae in these two regions of eastern India differing in topography and climatic regime showed a wide variation of occurrence of taxa in these specialized and mostly unpolluted habitats. Only 14 species of algae of which Phormidium grnulatum, Calothrix fusca, Dichothrix orsiniana, Nostoc commune under Cyanophyta, Spirogyra maravillosa, Staurastrum bieneanum var. ellipticum, Stigeoclonium longipilum, Oedogonium wyliei under Chlorophyta and Fragillaria virescence, Synedra ulna, Synedra ulna var. aequalis, Synedra ulna var. amphirhynchus, Synedra ulna var. oxyrhynchus, Cymbella tumida under Bacillariophyceae of Heterokontophyta were recorded in certain streams of both the regions . Of these 214 algal taxa, 97 were recoded first from the Eastern and North-eastern region region. Key words: Algae, streams, waterfalls, Odisha, Himalayas, North-eastern states INTRODUCTION Very little work has been done in India on documentation of algal flora in the lotic waters, especially in the mountain streams. Due to fast flow of water in such remote areas in hilly regions away from human habitation, seldom algal mats are seen in naked eye occurring in these springs. Literature survey showed that only a dozen streams in Maharastra (Gonzalves & Gandhi, 1952; 1954, 1962), Rajasthan (Gandhi, 1955), Karnataka (Gandhi, 1959, 1960), Kerala (Pugazhendi & al 2009), Assam (Saha & al 2007) and Odisha (Jena & al 2006a,b; Dey & al 2008) have been sampled for occurrence of algae. Even in these reports Gandhi either alone or with Gonzalves surveyed 9 streams in three states and Pugazhendi & al. (2009) two streams in Kerala documenting 263 species of diatoms under Heterokontophyta and they have not reported other algal species from these streams. Saha & al. (2007) documented only Cyanophycean forms (Cyanobacteria) belonging to 29 species in few streams of Kakoijana reserve forest, Assam. Jena & al. (2006a) and Dey & al. (2008) surveyed the streams of Similipal Biosphere Reserve in Odisha and reported 14 Cyanophyta, 23 Chlorophyta and 1 Diatom. Though there are few other records of algae in streams of different regions of India, either the name of the stream was not mentioned or how many locations of a particular stream were sampled which would represent algae of mountain streams was not clear (Parukutty, 1939; Prasad & Jaitly, 1985; Anand & Sharma, 1998; Joseph & Joseph, 1999; Nandi & Rout, 2000; Kumar & Rai, 2005). The documentation in unexplored habitats is important, especially from mountain streams which would have a vast wealth of algae so far not reported. Mountain streams of Himalayan region are important as these are unexploited, pristine habitats with less human activity, characterized by low temperature up to sub-zero in certain times of a year, and also is considered as an important biodiversity hot spot covering Indo-Burma region. Hence documentation and comparison of diversity of algal species occurring in these locations with those springs of plains, especially of Odisha state characterized by undulating plateau of Eastern ghats and rich with lotic water bodies was carried out for generating first comprehensive information on the algae these specialized lotic water bodies of Eastern and North-eastern region of region of India. MATERIALS AND METHODS Algal samples were collected from the streams and water falls of the Eastern and North-eastern region of India including the state of Odisha, West Bengal, Sikkim, Arunahal Pradesh, Mizoram and Nagaland during the period from May, 2008 to January, 2012. The GPS data of each collection site, type of the habitat, modes of occurrence of algae and the V.N.of the samples are given in Table-1. The algae occurred as epiphytic, epizoic, epilithic, epipsammic, epipelic etc. were scrapped from their substratum using forcep or scalpel, needle and/or tooth brush. Benthic algae were collected using