Itty bitty bright orange "slug"??

[User]

Best I can get

That’s looks more like a lettuce slug rather than a vasserria

 

[Vickie Watt]

I just saw it...it's too little to take a picture... about 5mm. I cant tell if it's got a shell or not. It has antennas like snails. Any ideas? Just an idea to point me in any direction?

I also just found one in my sump not sure if its good or bad ??

 

[EeyoreIsMySpiritAnimal]

I also just found one in my sump not sure if its good or bad ??

That looks more like a hair worm than a nudibranch

 

[WheatToast]

Looks like some kind of nudibranch. ~Shaun K

Looks more like a sea hare (possibly Elysia sp.) than a nudibranch (sea hares and nudibranchs are both "sea slugs" but different from one another). Elysia consume algae, with some species being capable of stealing their prey's chloroplasts to photosynthesize.

https://www.reefcleaners.org/store/out-of-season/oxynoe-slug-detail