Molluscs of , a High Altitude Brackish Water in

Boominathan, M and Ramachandra, T.V. Energy and Research Group, Centre for Ecological Sciences, Indian Institute of Science, Bangalore.

Lake 2010: Wetlands, Biodiversity and Climate change 1 Introduction l Pangong Tso is a trans-boundary lake between India and China, situated at an elevation of 4300 m. l High Altitude Cold Desert Changthang Wildlife Sanctuary (yet to be declared by State Govt. Jammu and ). l The lake harbours more than 300 species of birds, of which most of them are migratory (Namgail and Yom- Tov, 2009).

Lake 2010: Wetlands, Biodiversity and Climate change 2 l About 100 species are known to breed here. l This lake acts as a foraging ground for those birds. l They feed on molluscs, insects, and worms (Namgail and Yom-Tov, 2009). l Even though, Pangong Tso has international importance for biodiversity, the studies on invertebrates especially molluscs (which is one of the important food for many breeding birds) are sparse.

Lake 2010: Wetlands, Biodiversity and Climate change 3 l Sharma (2000) reported a fossil mollusc Radix auricularia (Syn: Lymnea auricularia), in the ancient lacustrine clay deposits above the present level of the lake.

l Godwin-Austen (1867) reported dead freshwater gastropod shells of Lymnaea and Planorbis, and a bivalve shell Pisidium, along the shoreline.

Lake 2010: Wetlands, Biodiversity and Climate change 4 Objective l To explore the molluscan diversity of Pangong Tso Lake.

Study area l The study was conducted in this lake region on September, 2010 near Merak village (Fig. 1)

Lake 2010: Wetlands, Biodiversity and Climate change 5 Figure 1. Pangong Lake and study site. Source: Googleearth, 2010.

6 Lake 2010: Wetlands, Biodiversity and Climate change Study area l Origin of Pangong Tso - Tectonic movements (Williams, 1991), glaciation, and melt waters (Gujja et al., 2003). l It receives water from numerous snow-fed streams (Negi, 2002). l The lake, depending on the water input, alternates between saline and (Chang, 1987).

Lake 2010: Wetlands, Biodiversity and Climate change 7 Materials and Methods l The pH were measured at the spot using EXTECH electrode (EC500). l Salinity were analysed in lab. l The empty molluscs shells were handpicked from a 10 m belt along the shoreline. l Stored in the plastic containers. l The shells were identified using Ramakrishna and Dey (2007).

Lake 2010: Wetlands, Biodiversity and Climate change 8 Results and Discussion l The pH was 9.3 at Pangong Tso, such with high salinity and pH were reported by William (1991).

l The salinity level of Pangong Tso Lake was 10.69 ppt, which was brackish (500 ppm salinity being upper limit for fresh water).

Lake 2010: Wetlands, Biodiversity and Climate change 9 l The length of Radix brevicauda and Radix lagotis were about 15 mm, from anterior (apex) to posterior (bottom tip of aperture).

Fig 2a. Radix Fig 2b. Radix brevicauda lagotis

Lake 2010: Wetlands, Biodiversity and Climate change 10 l The length of Valvata piscinalis were about 5 mm from anterior (apex) to posterior (bottom tip of aperture). l Gyraulus sp. was about 5 mm in diameter.

Fig 2c. Valvata piscinalis Fig 2d. Gyraulus sp.

Lake 2010: Wetlands, Biodiversity and Climate change 11 l Although all the four molluscs have been reported from the water bodies of Jammu and Kashmir, this is the first report for Pangong Tso.

l Periostracum (outer thin organic layer) on the shell surface indicates that this organisms are recent ones.

l Since the lake alternates between saline and freshwater, freshwater molluscs are continue to live in this lake.

Lake 2010: Wetlands, Biodiversity and Climate change 12 Conclusion l Pangong Tso is a brackish lake; however, the molluscs reported from this lake are of freshwater origin. l Initiating long-term study of molluscs from this vast, under-studied, pristine Himalayan lake using suitably developed sampling methods, will lead towards a breakthrough in documentation of mollusca. l Such studies will help in preparing conservation strategies for the rare biodiversity of lakes such as Pangong Tso.

Lake 2010: Wetlands, Biodiversity and Climate change 13 Acknowledgements l Tushar Prabhu, Rangarajan, Anshu Tomar, Lieutenant-General, and their team members. l Harish, Durgha, and Shankar Rao.

Lake 2010: Wetlands, Biodiversity and Climate change 14 References l Chang WYB. 1987. Large Lakes of China, Journal of Great Lakes Research, 13(3): 235-249. l Godwin-Austen HH. 1867. Notes on the Pangong Lake District of Ladakh, from a Journal Made during a Survey in 1863. Journal of the Royal Geographical Society of London, 37: 343-363. l Gujja B, Archana Chatterjee, Parikshit Gautam, and Pankaj Chandan. 2003. Wetlands and Lakes at the Top of the World. Mountain Research and Development, 23(3): 219–221. l Namgail T and Yom-Tov Y. 2009. Elevational range and timing of breeding in the birds of Ladakh: the effects of body mass, status and diet . J Ornithol, 150:505–510. l Negi SS. 2002. Cold Deserts of India. Edition 2. Indus Publishing, pp 248. l Ramakrishna and Dey A. 2007. Handbook on Indian Freshwater Molluscs. Zoological Survey of India, Kolkata. l Sharma VP. 2000. Geology of the Ladakh Region, J & K State with special reference to High Altitude Lakes. Paper presented at National Consultation Workshop: Conservation of High Altitude Wetlands. WWF-India, . l Williams WD. 1991. Chinese and Mongolian saline lakes: a limnological overview . Hydrobiologia 210: 39-66.

Lake 2010: Wetlands, Biodiversity and Climate change 15 Thank you

Lake 2010: Wetlands, Biodiversity and Climate change 16