Bioluminescence plays an important role in quorum sensing for some bacteria, where based on the density of signals, certain behaviors might be suppressed or enhanced. For example, quorum sensing is responsible for the creation of biofilms, where a densely-populated bacteria detect that there are enough of itself in an area to demonstrate coordinated activity. Bioluminescence itself can often be a result of quorum sensing, but I believe it can also be used as a signaling agent.
I think we can proximate quorum sensing via bioluminescence if implementation is feasible. The gist of it is that being within x distance of another member of your species can give you a bonus to a stat. We can provide a modification menu for bioluminescent vacuoles, where players can select from certain effects. For example, some effects could include:
- +5% speed
- -10% incoming damage
- 5% reduction in osmoregulation costs
- boosted growth rate
These effects would stack to a reasonable amount - if there are 3 of your kind close enough to you for those effects, +15% speed, capped out at +25%. The more bioluminescent vacuoles you have in a cell, the more intense the effect - instead of having one other member of your species near you result in 5%, you get a 7% bonus.
These effects would count if you are unicellular-colonial and in a cluster of your species, so that adds a nice little mechanic for when we make the transition to multicellularity more robust. When your organism is officially multicellular, cells in your colony won’t count towards the bonus, but the total number of bioluminescent vacuoles will increase so that the effect increases as well.