New York (dpa) - Previously unknown molecules make two specific shark species glow green in the sea - at least in the eyes of their peers.
This is what researchers around Jason Crawford of Yale University write in the journal "iScience" after analysis of the substances. This distinguishes the newly discovered mechanism from that of other fluorescent marine animals. The green glow, however, can only see other sharks - or people with the help of special cameras.
It could help the sharks to recognize each other. In addition, the special molecules could have a kind of antimicrobial effect and protect against infections. The two scientists investigated two types of catsharks, swell sharks and chain cat sharks for their study. That some cats shark fluoresce, was already known before.
"It's a unique system to see each other, which other animals do not necessarily have access to," Crawford said. "Imagine I'm a bright green, but only you could see it and other people would not."