Piya is touched when Moyna brings her dinner that's plain. When Kanai asks about dolphins, Piya insists that he should be interested in river dolphins because the first specimens were discovered in Calcutta. Piya mentions the Englishman who "discovered" the Gangetic dolphin in 1801, and then a man fifty years later who caught wind that a flood had brought "giant sea creatures" into a wetland area that's now a Kolkata suburb. The man found twenty dolphins in an evaporating pond. He thought they were pilot whales, and asked that the locals who had been trying to evacuate the whales keep two for him. That man decided they were a new species of pilot whale.
The locals who try to evacuate and save the dolphins indicates again that there's certainly a symbiotic relationship between the dolphins and the humans that live in close proximity. Their desire to save the animals suggests that they view them as creatures just as worthy of care and consideration as other humans, illustrating a balance between man and nature. The Englishmen, however, represent a relationship with nature in which man must discover and in doing so, triumph.
Twenty-five years later, a skeleton made its way to the British Museum, where scientists realized it didn't belong to a pilot whale at all. They discovered that this new species was a relative of the killer whale and called it Orcaella brevirostris. It became known as the Irrawaddy dolphin when someone found slight differences between the river and coastal dolphins. Though there's actually no difference, the name stuck.
As Piya describes the naming process, it shows that there are definitely times when language becomes somewhat nonsensical and doesn't actually communicate something true, given that the name Irrawaddy dolphin doesn't actually appropriately describe the animal.
Kanai feels tender towards Piya and asks if he can accompany her as a translator. She's not convinced it's a good idea, but Kanai insists he could be useful. Finally, Piya agrees.
Kanai's tenderness suggests that he's beginning to humanize Piya more as she talks about things she loves.