Ganges Indian narrow-headed softshell turtle ("Chitra indica"), Indian softshell turtle ("Nilssonia gangetica"), Indian peacock softshell turtle ("N. hurum") and Cantor's giant softshell turtle ("Pelochelys cantorii"; only in the lowermost section of Ganges basin). Most of these are seriously threatened. The river's most famed fauna is the freshwater Ganges river dolphin ("Platanista gangetica gangetica"), which has been declared India's national aquatic animal. This dolphin used to exist in large schools near to urban centres in both the Ganges and Brahmaputra rivers, but is now seriously threatened by pollution and dam construction. Their numbers have now dwindled to a quarter of their numbers
John Anderson (zoologist) and compared with "Orcaella fluminalis" and the Gangetic dolphin, "Plantanista gangetica". In 1875-6 he travelled to the same area under Colonel Horace Browne. This was cut short due to the murder of the consular officer Augustus Raymond Margary. Anderson made a third expedition for the Indian Museum in 1881–2 to the Mergui archipelago, Burma. Anderson made comparative studies of anatomy of the species that he collected. He worked on reptiles, birds as well as mammals such as of the genus "Hylomys". He also wrote on the ethnology of the Selungs of the Mergui archipelago. Many of the plant specimens that