Black Sea Slug, good or bad?

[Andy]

Just found him crawling across my front glass. About 2-3" long.

 

[Andy]

 

[Lionfish Lair]

Look up Dendrodoris nigra and see if that matches.

If it is a nigra, he's a super cool guy, but once he consumes any/all sponges in your tank he will unfortunately be without food.

 

[Andy]

Thanks. Must have been in there for a while as I haven't added anything
In months.

 

[Lionfish Lair]

You may be seeing him now, as he's getting big and may be running out of food where he was tucked away before.

 

[Andy]

I appreciate the help.

 

[Prozack199]

I don't trust any slugs. one died in a buddy's tank went down hill from there.

 

[Andy]

Thanks. I let him go as it looks like a sponge eater and in 380 gallons there is a lot of sponge for him to eat. Seen him once more since I let him go. Seems harmless.

 

[Lionfish Lair]

Some nudis are indeed toxic, but a lot have very specific diets that we cannot provide them with long term. As they slowly starve to death, their ability to 'nuke" a tank diminishes, so they basically aren't a threat, except in the smallest of tanks. In a 380 gallon, the point is moot and he's super cool.

If a nudi isn't IDable, I would pull them.

 

[Andy]

IDable?

 

[Lionfish Lair]

Identifiable.