A Cardinal Fish spitting light (’Fishy fireworks’ )

When the cardinalfish sucks up what it thinks will be dinner, the tiny sea creature, a type of ostracod, emits a burst of light. That burst saves the ostracod’s life - by getting it spat out. Not all ostracods create these light shows, and these cardinalfish can’t tell which tasty morsels will do so before eating when that bad boy lights, up, the fish really has a problem. If you have a lot of predators in the wild, then it’s best to stay hidden. That’s why the fish in the tank vomit up the tiny bio-luminescent ostracods. Otherwise, their bodies would illuminate from within, calling out to their predators, “Here’s DINNER!“ and getting them eaten for sure. This defense mechanism is the result of a light-inducing chemical mixture inside of the ostracod itself - which is set off whenever they are jostled. Many animals in the world have this capability to produce light, called bioluminescence, and they use it in different ways. In this case, its a survival tactic used