Hitchhiker Nudibranch

[Reedc200177]

Hi,

Bought an order of gulf live rock about two months ago. A few days later noticed a tiny nudibranch on the glass who vanished for six weeks then showed back up today looking like the pictures. Wondering what he is and if I should be concerned?

Looks different from the bad nudibranchs I've researched but can't find one that matches him. I can't tell that he's harmed or damaged anything either. Rock came from the gulf coast of Florida. about a half inch long and will only emerge in total darkness

 

[monkeyCmonkeyDo]

I would remove as it's better safe than sorry
D

 

[taricha]

agree, nudibranches that look like algae I lean toward keeping. Those that have shapes or colors to blend with coral polyps are a definite remove.

 

[sixty_reefer]

No point in removing/killing this is from the aeolidiella family, it will most likely die from starvation eventually.

 

[Eric R.]

@Reedc200177 you can try asking @The Wyld Zone on the humble fish community forum. He's a slug ID specialist. Unfortunately he doesn't post here anymore. Would be neat to get an ID!

 

[Eagle_Steve]

Hi,

Bought an order of gulf live rock about two months ago. A few days later noticed a tiny nudibranch on the glass who vanished for six weeks then showed back up today looking like the pictures. Wondering what he is and if I should be concerned?

Looks different from the bad nudibranchs I've researched but can't find one that matches him. I can't tell that he's harmed or damaged anything either. Rock came from the gulf coast of Florida. about a half inch long and will only emerge in total darkness

Almost looks like a berghia rissodominguezi or berghia columbina. Either of those will only eat small nems and some small corallimorphs. Small nems being aiptasia, curlyque nems, light bulb nems, warty nems, some small tube nems, etc. They may also eat small shrooms like ricordia. I have caught a few of these and seen them in shroom patches while diving to collect ricordia. I have also found some in tide pool munching on small warty nems.

If you did not want curlyque nems, light bulb nems or warty nems, leave it in the tank and it will eat them. It will perish once it runs out of food.

If you know someone with aiptaisa and no fish that would eat it, give it to them. They will be thankful.

 

[ISpeakForTheSeas]

… Hard to say for sure what nudibranch it is because there are so many species of nudibranch and even a lot of the ones with more distinguishing features can be difficult to get an ID on (very little is known about a lot of the species, probably because their incredibly specific living/dietary requirements mean they’re not really of any commercial interest). …

If you know where it came from (i.e. if you know what area of what ocean) that might help narrow it down, but again, ID’ing these guys is incredibly difficult unless they’re one of the best known species.

You could try offering it a little buffet of potential food options and see if it eats anything, but odds of it doing so are slim to none without a 100% ID even if you pick something closely related to what it would naturally eat. Most likely it will starve in your tank.

I hate to start off by quoting myself from another thread, but the above is usually pretty helpful with nudibranch ID threads.

Long story short, nudibranch ID’s are difficult. It could be harmless, it could be a problem. Most likely it will starve to death in your tank.

Even if it is a zoanthid eating nudibranch, studies have shown that they have strong preferences for highly specific species of zoa/palythoa - to the point where in the wild they totally ignored other species to target the ones they wanted. Knowing how specialized some nudibranchs are, it wouldn’t surprise me if they would literally rather starve than even attempt to eat a non-preferred zoanthid species. This means you could have a zoanthid eating nudibranch in a tank full of zoas, and they still might starve to death.

If you have some crazy expensive corals or something in your tank and you don’t want to risk the off chance that this nudibranch will eat them, you can sump it or give it away. Most likely it will be fine, but there are no guarantees. Alternatively, you can keep it in the tank, document if it eats anything, and remove it if it starts eating something you don’t want it to.

 

[SlugSnorter]

Hi,

Bought an order of gulf live rock about two months ago. A few days later noticed a tiny nudibranch on the glass who vanished for six weeks then showed back up today looking like the pictures. Wondering what he is and if I should be concerned?

Looks different from the bad nudibranchs I've researched but can't find one that matches him. I can't tell that he's harmed or damaged anything either. Rock came from the gulf coast of Florida. about a half inch long and will only emerge in total darkness

young opalescent nudi? better remove nudis, most carry toxins of some sort and when they die it can cause issues

 

[Reedc200177]

It does seem to be a ringer for some kind of berghia nudibranch.

I'm not sure what it's eating but it's quadrupled in size and the few corals and anemones I have are totally undisturbed. When I've caught it out and about its been just cruising around the sand bed or rockwork. There are a few aiptasia or something that looks like it popping up which I've been trying to kill as I see them.

Maybe I'll observe it for a day or two since I just now discovered it and it must be eating something to get so big and so far seems to have not harmed anything, but will be watching closely (especially since I now have no idea where it went)