DNA Test Reveals Identical Beaked Sea Snakes are Two Separate Species

A new study finds that the deadly beaked sea snake is not a single species, but two different species that evolved separately.

Until now, it was believed that the poisonous Australian and Asian beaked sea snakes were from the same species and closely related to each other. But a team of researchers from the University of Queensland, Australia, have found that these two snakes are completely unrelated.

The research team carried out a DNA analysis and noticed that the two species have different DNA. The DNA analysis shows evidence of convergent evolution, a process where the species from unrelated lineages share the same biological trait. The two sea snake species appeared in two separate evolutions, but resulted in looking similar.

As a result of the study, the Australian beaked snake which was called as Enhydrina schistosa, has been elevated to species status and given a new name [Enhydrina] zweifeli, based on the region in New Guinea where the snakes are found. The new snake will be placed in a separate genus to the true Enhydrina genus, said the researchers.

However, the Asian beaked sea snake will retain the original name Enhydrina schistosa.

The findings will have significant implications on snake bite management, as only one sea snake anti-venom has been developed, assuming that both are of the same species because of their unique habitat. The two species live in silt-filled shallows of tropical estuaries both in the Asian and the Australian regions, researchers said.

"This mixup could have been medically catastrophic, since the CSL sea snake anti-venom is made using the venom from the Asian snake based on the assumption that it was the same species," associate professor Bryan Fry,  from the University of Queensland, said in a statement.

But researchers note that the anti-venom has worked effectively for sea snake bites of both the species. "Luckily, the anti-venom is not only very effective against the Australian new species but actually against all sea snakes since they all share a very stream-lined fish-specific venom," Fry said.

The findings of the study, "Molecular evidence that the deadliest sea snake Enhydrina schistosa (Elapidae: Hydrophiinae) consists of two convergent species", are published in the journal Molecular Phylogenetics & Evolution.