[igorkraw]

In the beginning of the PhD, to help with rent I contracted to help develop computer vision algorithms in this field, only PoCs, never got very far.

And interesting thing is that the lice apparently evolve super fast, including getting translucent and resistant against poison

[globalise83]

That's interesting! They might also evolve a tendency towards moving to the left flank of the fish.

[ndr42]

Reminds me of the evolution of fish that prey on scales of other fish to have two distinct types with the mouth on the right or left:

https://en.wikipedia.org/wiki/Perissodus_microlepis

Depending on which type is more frequent the other is more successful because the prey is more cautions on the other side...

edit: spelling

[globalise83]

My comment was half in gentle jest, but you have really found a relevant example there - thanks for sharing. I guess I have a potential PhD project if I ever want to get into maritime biology: "The Dark Side of the Fish: How Crafty Parasites Outmaneuver High-Tech Pest Control"

[greggsy]

Fish are known to swim in both directions.

[amelius]

I guess they swim in the direction of the majority which is probably always the same in a circular tank with many fish.

[woleium]

you can move the laser too!

[steve_adams_86]

I’ve noticed that selective pressure on shrimp in an aquarium leads to colour morphs very, very quickly. I bet lice are the same.

I’ve had tanks where shrimp will match their surroundings quite closely within a year or so. This would be due to some micro predator being present and picking off any babies that are easy to see. Shrimp have babies frequently and the only ones that survive in those conditions are able to blend in really well. Every 2.5 months or so a new generation becomes sexually mature and has dozens of babies every 8 weeks or so.

It’s a fun hobby because you can actually develop your own morphs in a matter of only years if you want to.

So it’s not necessarily evolution, but pigments developing (or not) due to environmental pressures.