The fish has previously been classified under the genus Puntius, comprising around 120 species of small tropical fish known as barbs.
Pethiyagoda, an ichthyologist and internationally acclaimed conservationist, said extensive studies in India and Sri Lanka showed that the level of diversity among such fish was "much greater than previously suspected".
This was partly the reason that the study group had chosen to name the new genus after the 71-year-old Dawkins, the British author of the anti-religion polemic, The God Delusion.
"Richard Dawkins has through his writings helped us understand that the universe is far more beautiful and awe-inspiring than any religion has imagined," Pethiyagoda told AFP on Monday.
"We hope that Dawkinsia will serve as a reminder of the elegance and simplicity of evolution, the only rational explanation there is for the unimaginable diversity of life on Earth," he said.
Male Dawkinsia barbs advertise their fitness by growing long fin filaments that make them more attractive to females but also dangerously conspicuous to predators.
"The filaments are rather like the peacock's tail, expensive ornaments that place their owner at greater risk while offering him the reward of being the preferred choice of females," Pethiyagoda said.The genus re-classification followed an eight-year study of the DNA, bone structures and overall anatomy of Puntius species.