A study of organisms in Bermuda’s caves has given researchers insight into how life adapts to permanent darkness.

Scientists from the US and Germany compared crustacean species from caves around the world, studying Mictocarididae in Bermuda, Spelaeogriphacea in South Africa and Thermosbaenacea in Italy.

While the organisms come from vastly different regions, all three are blind and have developed small stalks where their eyes used to be.

Their findings, published in the online journal BMC Neuroscience, showed that not only did the species lose their sight, they had undergone changes to their brain and nervous system, improving their sense of smell and taste.

Tom Iliffe, professor of Marine Biology at Texas A&M University, who carried out much of the research on the Island, told online publication Futurity that some of the species first colonised the caves more than 180 million years ago.

Since then, they have undergone “regressive evolution”, losing body features which are not used.

“Even with no light in the caves, evolution continued to proceed as it always does — these creatures were able to adapt and survive in this totally dark environment, while life on the surface of the Earth changed radically,” Dr Iliffe said.

“Our findings suggest that these creatures, as they spent longer and longer time in complete darkness, changed independently during this evolutionary process, and they gradually reduced brain functions that were no longer needed.”

Bermuda’s caves are home to about 60 native and indigenous marine invertebrates, ranging in size from large shrimp to microscopic organisms, with some species found only in a single cave.

Dr Iliffe has made numerous trips to Bermuda to carry out research over the past 12 years, mapping the Island’s cave system and studying the life found within.

In 2011, he led a four-man team in the deepest manned scuba dive in Bermudian waters, swimming 444ft to what was the edge of the Island during the last Ice Age.