caught a white with white flourescence nudibranch

[Tuan’s Reef]

its about half inch. its white and has a glowing white outline. i have it in a cup at the moment. anything to be concerned about? I have a wrasse in quarantine inbound in a couple of weeks.

 

[Chrisv.]

Awesome. Can you get pics of it glowing somehow? Nudibranchs are almost never a good thing in a reef. They are obligate cnidarian feeders. The species that eat aiptasia are useful, but like I said, they ALL eat cnidarians.

 

[Tuan’s Reef]

It's pretty creepy lol

 

[Chrisv.]

Oh is that a burghia?

 

[Chrisv.]

do you keep zoas?

 

[Tuan’s Reef]

i don't know if its a berghia or not, but i do keep zoas. He won't be going back in that's for sure lol

 

[ISpeakForTheSeas]

Awesome. Can you get pics of it glowing somehow? Nudibranchs are almost never a good thing in a reef. They are obligate cnidarian feeders. The species that eat aiptasia are useful, but like I said, they ALL eat cnidarians.

Just a small correction here, not all nudibranch species eat cnidarians (the vast of majority of them do, though). Dorididea (Dorid) nudibranch species, for example don’t eat cnidarians at all. Also, while many nudibranchs could be harmful in our tanks, many (probably most) will just starve in our tanks because of their highly specialized diets (many nudibranchs only eat one specific food and nothing else - such as the Portuguese-man-of-war eating Blue Dragon Nudibranch). Even zoanthid eating nudibranchs have been found to only eat specific zoa/paly species (though I’m not sure if this a preference or a requirement - one of the problems faced by field studies that lab studies can avoid).

Anyway, because of their specialized diets, my usual advice is if you’re not willing to lose something in your tank, you’re probably better off removing the nudibranch- otherwise, try and found out if it is eating something in your tank, and, if it is eating, document what it eats and decide if you want to keep the nudibranch or not based on that.

TLDR; removing it (like Chrisv. Suggested) is the safest choice.

 

[Chrisv.]

Just a small correction here, not all nudibranch species eat cnidarians (the vast of majority of them do, though). Dorididea (Dorid) nudibranch species, for example don’t eat cnidarians at all. Also, while many nudibranchs could be harmful in our tanks, many (probably most) will just starve in our tanks because of their highly specialized diets (many nudibranchs only eat one specific food and nothing else - such as the Portuguese-man-of-war eating Blue Dragon Nudibranch). Even zoanthid eating nudibranchs have been found to only eat specific zoa/paly species (though I’m not sure if this a preference or a requirement - one of the problems faced by field studies that lab studies can avoid).

Anyway, because of their specialized diets, my usual advice is if you’re not willing to lose something in your tank, you’re probably better off removing the nudibranch- otherwise, try and found out if it is eating something in your tank, and, if it is eating, document what it eats and decide if you want to keep the nudibranch or not based on that.

TLDR; removing it (like Chrisv. Suggested) is the safest choice.

I stand corrected! Are they all carnivorous?

 

[JoJosReef]

Looks like the ones that came off my gulf live rock. I gave them to a local reefer breeding Berghia and they ate aiptasia.

 

[ISpeakForTheSeas]

I stand corrected! Are they all carnivorous?

Actually, no - though I only know of one (so far) that has been confirmed as an herbivore: Polycerella emertoni - once thought to eat bryzoans, upon much closer examination (including a stomach content exam) it was found that it actually eats diatoms which grow on the bryozoan it was thought to eat.

It’s now suspected (based on this and the shape of other nudibranch teeth) that several other nudibranch species have been similarly mistaken as carnivores eating the substrate on which they live when they may in fact be herbivores. Unfortunately, these kinds of studies are rarely done, likely because they’re expensive and nudibranchs aren’t really of any commercial interest (so it’d be tough to get funding).