the Angler fish
- Challenge: survive in complete darkness
- Strategy: create your own light!
- Solution: bioluminescence
There are angler fish in most of the world’s oceans, but you have to dive deep, to about 4,000m, to find them! The light of the sun does not penetrate to this depth, so everything is in darkness. Finding food or, for that matter, a partner, is no easy task. But the female angler fish has found an answer to the problem: she carries her own little “lantern” around with her!
This lantern is a bioluminescent light that hangs from a sort of rod protruding from the fish’s head. It contains millions of light-emitting bacteria. It lures prey by waggling the rod back and forth. But this light-emitting bait also attracts male anglers! The male angler fish is very small: this tiny light in the dark increases the chances of the male and female finding each other. Once attracted, the male attaches himself to the female, like a parasite, providing her with a source of sperm for the rest of her life.
