Sea slug? Reef safe or not?

[rongy]

Hello, need help id the small critter I found in the tank. It looks like some kind slug, with reddish color. Reef safe or not?

 

[ISpeakForTheSeas]

Elysia sp. Sacoglossan slug - algae eater:

Elysia flava or E. obtusa - harmless/beneficial Sacoglossan slugs. They're herbivores, with E. obtusa known to feed on Bryopsis, while E. Flava is thought to feed on Cladophora. As mentioned below, I don't know if these are required feeds or just strongly preferred feeds:

Some lettuce slugs (typically from the genus Elysia) will eat nuisance algae species, but their wild diet varies pretty drastically from one species to another, and some species have some pretty specific wild diets (I don’t know if these are required diets or preferred diets, but Reef Cleaners reports that they'll eat just about any green, fleshy algae). That said, Elysia slugs generally feed on siphonalean algae such as Caulerpa, Codium, Acetabularia, Halimeda, Udotea, Byropsis, and Valonia spp. So, in theory, these guys should eat nuisance algae that pops up in your tank.

 

[rongy]

Elysia sp. Sacoglossan slug - algae eater:

Thank you! Unfortunately, I already tossed it lol, but I think there are more in my tank