Is this a nudibranch? or a bug?

[txbonds]

Is this a nudibranch, or bug, or what, and how do I get rid of them if they are bad? I spotted about 5 or 6 of them this morning and a couple are on or around my corals.

See dead center on tip of rock for nudibranch looking critter:

Another one and in this shot looks kind of like a bug:

Also spotted a shell-less looking snail last night but didn't get a picture. Completely different looking than above. Was long and flat and sort of clear looking with two horns on one end. I'm assuming it could be a nudibranch also. From below, you could see a long central tract like a digestive tract. He was skimming along the glass right at the sand surface. About the size of my thumb from the knuckle to the tip. Can't find him this morning.

 

[AJSTITAN14]

Definitely a nudibranch although I don't know anything about it.

2nd sounds like a stomatella snail, a lot of snails have a fleshy covering over their shells so peole think they are shelless.

 

[pagojoe]

The slug experts should chime in soon, but it looks like it has a lot of green in the cerata--usually a sign it's storing chlorplasts or that it's feeding on algae. Some very similar-looking slugs feed on corals, though. I'd look through the Placida and Ercolania species on http://www.seaslugforum.net/specieslist.htm before I started removing them. If they are sacoglossan slugs rather than nudibranchs, they won't be a problem.

Cheers,



Don

 

[txbonds]

I first spotted one on a piece of tonga branch that I have that is covered with Zoa's. He was down in between the zoa polyps, but I couldn't tell if he was eating the polyp or perhaps something on the tonga branch like algae. I spotted another one on the stoney skeletal part of a lobo, just below the tissue of one of the lobo's. Again, too far from the glass to tell what it was actually doing.

The one I got pictures of was on a rock not near a specific coral, but nearer to the glass. These guys were all out after lights out as well, so I'll advise in a few during lunch if they are there during daylight hours.

I was out of town for 3 days and when I got back I noticed that this colony of zoa is not opening much. Then the second night after my trip, I found these as well as the shell-less snail or nudi looking thing that I didn't get a picture of.

 

[txbonds]

Okay, came home for lunch and found 4 of the little buggers. 3 of them were as best I could tell munching on the zoa colony I mentioned above. If you look dead center, you can see one on top of a polyp in this pic:

Here is a shot of one of them after removal:

I managed to get 3 of them out, and I am pretty sure I smooshed one as only a few parts came out when I grabbed with tweezers. Will they regenerate like a starfish, or does smooshing or breaking one up kill it?

Thanks.

 

[Leviathan_XE]

Hardly an expert but going from what I've read on this board. It does appear to be an zoa eating nudi but you've already come to that conclusion it seems. They do tend to be colored the same as the zoas they munch on for camoflauge. If damaged enough it will die just like anything else but I would worry about the toxin that they carry, which I could assume they absorb from the zoas they eat. I would try to remove as many as you can and then dip the colony to kill off any that you don't see.

 

[txbonds]

Thanks. Will do.

What is best to use for the dip?

 

[Leviathan_XE]

I think most people go with just plain freshwater dipping the zoas for 20-30 secs. You'd be surprised how much micro life will fall off in that short amount of time. But I really don't think there is a time limit. I've hear that some folks have FW dipped for up to a few minutes, the longer you dip the more critters you'll see, but just remember if you go too long you may harm your zoas. Just watch them closely and use your best judgment. However long you decide, you'll still prob do less damage than the nudis that are eating them.

 

[bobbychullo]

looks like a zoa eating nudi. i have not seen them in my tank but the research ive done matches your pic. I had monti nudis that looked similar but are white, the zoa nudis are brown.

i was told to dip in ReVive to get the nudis to drop off but you have to stay vigilant because dips do not remove the eggs. you'll have to re-dip if there are eggs that hatch later.

it is recommended during the dip to gently swish the zoas in the dip container to help the critters fall off. you can hold the zoas in your hand and invert the colony to let gravity do its thing too

 

[txbonds]

I'm hopeful that I got them out before there were any eggs, but I'll definitely be keeping an eye on them over the coming days. I'm already preparing myself to find more when I get home shortly.

Thanks for the tips.

 

[txbonds]

Found a 5th one this morning. Did a fresh water (RO/DI) dip on the zoa colony this morning and gave it a good swishing shake and he fell right off.

Looks like there might be a few hold outs, so I'll have to keep a watch for sure.

Thanks again for the tips.

 

[bobbychullo]

well, I just found 2 on one of my zoa colonies. :/

i can confirm they were a color match for my zoas. the flesh of the colony between the polyps is purple and the dang nudi was purple as well...

i immediately dropped them in a dip of revive for 15 mins. i yanked the one sucker i could see off with some tweezers but after about 10 mins in the dip and a couple of swishes another dropped.

i inspected the colony up close, out of the water with my flashlight. i could not find anymore. wishful thinking but i am hoping they were the only ones LOL!!

there was some polyps dying but ive only had them a week and a half and a few seemed to be making a recovery so i figured it was just from less than optimal conditions at the LFS. my other colonies show no signs of die off or closing polyps. in fact the colony i dipped is almost fully open after 10 mins back in the tank...

 

[bobbychullo]

just found 5 more on another colony...

 

[txbonds]

My tonga branch colony is opening back up today but I had a number of small colonies that I noticed had not opened and I found some almost microscopic ones on it. I'm talking the size of a pin head. I dipped it in RO/DI water and gave it lots of swishing. Just put it back in and will see how it does. I'm not seeing them on it at the moment.

I know exactly where mine came from too, as I recently bought a new piece of zoa covered live rock, and shortly after is when this problem started.