In his book, the coming of Tan, Riley Martin (1946-2015) describes how he was taken on board of a huge egg-shaped "mothership" in the vicinity of Saturn. On the mothership he learned it was inhabited by seven different species of intelligent technological life forms, of which the Nyptonians are one. Riley calls them the water people  and describes them as fish like humanoids equipped with gills for breathing underwater. He says they are peaceful beings who value science and technology. Supposedly, they have hidden underwater bases right here on earth.

No other authors mention this species. Many researchers question his credibility.