These 2 stamps are India-Philippine joint issue in 2009 featuring Dolphins.
The 5R stamp shows Gangetic Dolphin,which is primarily found in the Ganges and Brahmaputra Rivers and their tributaries in India, Bangladesh and Nepal.It is the most threatened cetacean and among the world's most threatened mammals. They are threatened by accidental gill net fishing, bycatch, use of their oil as fish bait, by pesticides and river fragmentation from agricultural irrigation and dams. It is listed as an endangered species in the IUCN Red Book and as a Flagship Species by WWF. And it has been recognized by the government of India as its National Aquatic Animal.
The 20R stamp shows Whale Shark,which is a slow moving filter feeding shark, the largest living fish species. The largest confirmed individual had a length of 12.65 metres and a weight of more than 21.5 tonnes.The shark is found in tropical and warm oceans, lives in the open sea with a lifespan of about 70 years. The species originated about 60 million years ago. Although whale sharks have very large mouths, they feed mainly, though not exclusively, on plankton, microscopic plants and animals.