May 3, 2024

Sea Snakes See in Technicolor: A Reversal of Ancestral Vision Loss

The annulated sea snake has evolved to see a broader series of colors, a notable turnaround from its forefathers who lost color vision due to adaptations to low-light environments. This evolution consists of 4 copies of the opsin gene SWS1, supplying level of sensitivity to longer wavelengths discovered in their ocean environments. This broadened vision assists these sea snakes better identify predators, victim, and potential mates.
A new research study exposes that the annulated sea snake, a venomous snake types indigenous to the oceans of Australia and Asia, has actually evolved to perceive an extended color range.
A new paper in Genome Biology and Evolution, published by Oxford University Press, finds that the annulated sea snake, a species of venomous snake found in ocean waters around Australia and Asia, appears to have developed to see a prolonged palette of colors after its forefathers lost that ability in reaction to changing environments.
Color vision in animals is mainly identified by genes called visual opsins. While there have been several losses of opsin genes during the advancement of tetrapods (the group consisting of amphibians, mammals, and reptiles), the development of brand-new opsin genes is incredibly uncommon. Before this research study, the only development of new opsin genes within reptiles appeared to have occurred in species of Helicops, a genus of snake from South America.

Hydrophis cyanocinctus (annulated sea snake). Credit: Chris Mitchell/ Genome Biology and Evolution
The history of elapids, a household of snakes that consists of cobras and mambas in addition to the annulated sea snake, presents an opportunity to examine the molecular evolution of vision genes. Early snakes had actually lost 2 visual opsin genes throughout their dim-light burrowing stage and could just view a really minimal range of colors.
Researchers here discovered that the annulated sea snake has 4 intact copies of the opsin gene SWS1. The research studys authors believe that this level of sensitivity might provide the snakes with much better color discrimination to differentiate predators, victim and/or potential mates against colorful marine backgrounds.
” The earliest snakes lost much of their ability to see color due to their dim-light burrowing way of life,” said the papers lead author Isaac Rossetto. “However, their sea snake descendants now inhabit brighter and more spectrally complicated marine environments. We think that recent gene duplications have drastically expanded the series of colors sea snakes can see. For recommendation, us people have actually a similarly expanded level of sensitivity to colors, while cats and pet dogs are partially color-blind much like those early snakes.”
For more on this discovery, see The Remarkable Vision Evolution of Sea Snakes.
Referral: “Functional Duplication of the Short-Wavelength-Sensitive Opsin in Sea Snakes: Evidence for Reexpanded Color Sensitivity Following Ancestral Regression” by Isaac H Rossetto, Kate L Sanders, Bruno F Simões, Nguyen Van Cao and Alastair J Ludington, 12 July 2023, Genome Biology and Evolution.DOI: 10.1093/ gbe/evad107.
Financing: Australian Research Council Discovery Project.

The annulated sea snake has progressed to see a wider range of colors, a significant reversal from its ancestors who lost color vision due to adaptations to low-light environments. The history of elapids, a family of snakes that consists of cobras and mambas in addition to the annulated sea snake, presents an opportunity to examine the molecular evolution of vision genes. Scientists here found that the annulated sea snake possesses four intact copies of the opsin gene SWS1. We believe that recent gene duplications have actually drastically expanded the variety of colors sea snakes can see.