What purpose could algae have to glow in the dark?
I means, they have no eyes and they cant profit from it? from a predatory stand point it might as well signal grazer to come feast? Which is not very useful.
In my fantasy world, I have phytoplankton that are glowing during the nights. What would drive evolution to produce glowing algae, that glow every nights and all night long, on a alien planet?
Thanks for you input
Two possibilities:
To warn off predators that the algae are bitter or poisonous. Easier to be recognized the second time.
To attract commensal fish that will eat dead and decaying algae, or fish that would eat the algae.
Trees use smell.
If your trees get eaten by masses of insects, nothing will seem to happen at first. But soon the trees will start to smell tremendously, and before the week is over masses of birds have eaten most of the insects and an equilibrium is created where some insects survive to eat the trees while birds get their share and enough trees survive.
Algea would use light to attract predators of whatever eats them. Additionally the algea could use chemical synthesis for part of their process to stay alive which happens to generate light.
Light can also be a warning if the algea is poisoness, signalling creatures not to eat it. This is similar to animals and insects like wasps that use bright contrasting colors to make it clearly visible that they might attack.
Bioluminescence is used as a defence mechanism to draw predators towards the creature trying to eat the plankton. Furthermore, the tiny flashes of light disorientate and surprise predators.
Imagine just minding your own business while you see a UFO. You would be pretty scared right? For predators, this is like the same thing. You don't mess with the things that you can't understand. What you can't understand is what you fear. Just think about deers. They are pretty smart when it comes to escaping from threats. But any car with it's lights on? They look at it like you would look at a UFO. So, long story short, it might glow to confuse and possibly scare any possible threats.
