Most species have eyes at the ends of their arms, which they use to navigate. The starfish eyes were already thought to be fascinating. Suddenly the well-developed eyesight makes more sense,” says Garm. “It was really interesting for us that two of the species are bioluminescent and able to produce light. So what did the starfish use their eyes for in the darkness the deep ocean? Read More: Greenland could be home to several coral reefs One of the starfish species, the deep sea Novodinia Americana, had such a well developed eye that, according to the new study, it supports sight that is better or just as good as starfish living in shallow sunlit waters. Three of the starfish that we studied live more than 400 metres deep where there’s never sunlight. “But we were surprised when we discovered that we were wrong. Animals that live in complete darkness often lack sight and instead use other senses such as sense of smell to navigate,” says Garm. “We had assumed that starfish from the deepest and darkest places didn’t have eyes. Surprisingly, all species except one had eyes.
In the study, scientists investigated 13 species of starfish from Greenland, from both shallow and deep water habitats. Read More: Climate Change draws invasive species to the Arctic It’s an advanced form of communication, which was previously unknown in animals like starfish,” says Anders Garm, associate professor at the Department of Biology, at the University of Copenhagen, Denmark, and lead-author of the new study. “Our hypothesis is that they use light to send signals to each other and perhaps show that they want to mate. The starfish are thought to use the light to find their way through the dark and to communicate with potential partners.
In a new study, scientists have described bioluminescent starfish that live in the deep seas off Greenland.
At some point, all sunlight disappears and the sea is pitch black. The deeper you descend into the ocean, the darker it becomes.