Box snails?

[Llarian]

My zooanthids in my nano have been ailing for a while, while all the other sessile inverts in the tank have been fine. I suspected water parameters at first, but they're fine.

So, now that most of my smaller-polyped zoo colonies have been decimated, I saw these 3 guys hanging out on the rocks near one of them.

They don't quite have the look of Heliacus, but could these be my culprits? If so, how can I track down the other inevitable ones?

Thanks!

-Dylan

 

[wrightme43]

I got em too. I also believe they are the ones eating my zoos. I have been picking them out by hand. It seems like a losing battle. Every time I pick all I can see out and throw them away, there are more. I am almost resigned to losing all my zoos and letting the little buggers starve to death. Hopefully in a horrible manner. Sorry I dont like things to eat my corals. LOL. I know it is my fault. I have dipped and shook and shook and dipped to no noticeable effect on the numbers. However I also see them on the live rock far away from the zoos. Do they also eat algae, or are they just wandering around looking to kill more stuff. Or as usual I could be wrong and these guys are harmless and I am just confusing them with sundial snails. Anybody Know?
Steve

 

[NaH2O]

Those are not heliacus snails, which look like this:

As you can see, the heliacus snail has a cone shaped operculum (little trap door that shuts them in). Those snails, although I don't have a definite ID, do not appear to be anything bad. I would think that they are more likely eating something on the rocks the zoos are attached to. Something else to consider. A local reefer here had a dwindling population of zoos, when one day he discovered a Eunice sp. worm biting off zoos while he watched. The worm stretched a good 5 inches or so, small compared to how big they can grow. Dylan, another option would be to check at night for the zoo eating nudibranch. I also caught a peppermint shrimp munching on my zoos. What do the zoos look like? Are they still opening up, staying closed all the time, covered with gunk?

 

[wrightme43]

Ok Nikki for me where can I find more about the Eunice worm. I have found no nudis, no fungus, and it looks like I have been killing innocent snails. I have one time seen a very long white worm stretched out over toward the zoos but as soon as the light hit him he was gone in a flash. Steve

 

[mattseattle]

I think they are this:

Collonista are "mini-Turbo snails." They are seldom purchased by hobbyists, but are relatively common in reef tanks anyway, because they appear to hitchhike in on live rock or in some live sand. When hobbyists first see them, they presume them to be "baby" grazers of some sort. Instead, they have some of these animals. They reach a maximum adult size of about 1/4th inch (6 mm) in height and diameter. They are often tan to white and have mottled brown color patterns on the shell. They can be distinguished from all other Trochoideans by their small size and the presence of a small pit or hole in the center of the calcareous operculum that plugs the aperture. They reproduce well in aquaria, and are quite good grazers. If present in large numbers, they may effectively replace all other grazers in our systems

 

[mattseattle]

a picture to boot!

 

[Llarian]

Dylan, another option would be to check at night for the zoo eating nudibranch. I also caught a peppermint shrimp munching on my zoos. What do the zoos look like? Are they still opening up, staying closed all the time, covered with gunk?

I've checked for the nudi but have not seen one yet. As most of my zoos are gone (there weren't that many to begin with, its a 5G nano), there's little room for one to hide anymore.

The only shrimp I have is an anemone shrimp, and he seldom ventures down to the zoos, he prefers hanging out on my mushrooms.

Some of the surviving zoos in the middle of the colony still open, but the ones one the edges do not, or open halfway. The far edges that used to be covered with polyps are now bare.

There's no fungus or other gunk around the colonies.

Oddly, the larger polyed zoos I have do not seem to have been effected yet, they're still fine. Its only the smaller green ones (6-7mm polyps) that are. Two separate colonies of these on remote rocks are exhibiting the same die off. I can't find anything on them at night other than what appear to be amphipods.

-Dylan

 

[NaH2O]

Matt - thanks for putting up that info. I knew I read about them somewhere when doing the discussion of the week on snails (I believe that is from one of Shimek's articles).

Steve - the Eunice species have 5 antennae like things coming out of their "head". I do not believe all of the species in this genus are predatory, but some are. Steve Weast had a monster in his tank (6 feet). Here is a link to our gallery, and you can see several of the Eunice spp. at the bottom: Invert ID - Worms. Here is an article: A Large Worm Turns...

Dylan - have you tried any dips yet?

 

[Llarian]

Dylan - have you tried any dips yet?

Nope. That's my next step.

-Dylan

 

[wrightme43]

Thank You very much Nikki, I read the article and looked at all the pictures. The one the describe as able to disapper in a blink of a eye is what mine looks like. It says they are not predetory so back to searching for a reason. LOL Steve

 

[gobie]

nikki is right about the worms. i found one thing that is asure fire bet is take fae rocks out and place them in a bucket of salt water with a low ph value the worms cant handle the ph shift but the zoos should be ok. dont do this too much at a time cause it kills more than just those worms. i pulled out a worm once that was easily 9" to a foot long.

 

[Elmo18]

I think they are this:

Collonista are "mini-Turbo snails." They are seldom purchased by hobbyists, but are relatively common in reef tanks anyway, because they appear to hitchhike in on live rock or in some live sand. When hobbyists first see them, they presume them to be "baby" grazers of some sort. Instead, they have some of these animals. They reach a maximum adult size of about 1/4th inch (6 mm) in height and diameter. They are often tan to white and have mottled brown color patterns on the shell. They can be distinguished from all other Trochoideans by their small size and the presence of a small pit or hole in the center of the calcareous operculum that plugs the aperture. They reproduce well in aquaria, and are quite good grazers. If present in large numbers, they may effectively replace all other grazers in our systems

Totally agree with this In fact, I saw some crawling in a live rock holding tub at a local fish store. They are tiny, and have light mottled shells. They do in fact, look like mini turbo snails. These guys have a different shell pattern than the Astreas. Again, like Matt says, these are good guys.

I don't believe I have any, as I didn't buy any rock at that time. I think I have enough snails, though

- Elmo

 

[mattseattle]

one thing i've noticed about them is they usually only come out at night. about 8 months ago i noticed i had one or two at night but now i probably have easily 50 or 60 that come out at night and cruise on the glass, the bare bottom, the rock and all. so they do reproduce quickly. for a while i would try to pull them out because i thought they were 'bad' snails but then i found that information on them. now i just let them reproduce and clean my tank.

 

[elvis]

So this means the peppermint shrimp I just added is going to start eating my zoo's? I thought they were "reef safe"

 

[NaH2O]

Not necessarily, Elvis. I'm probably more of the exception rather than the norm. I don't feed my tank very often, so that may have contributed to their taste for zoanthids. Once they finished off my aiptasia, I didn't supplement them. Now, they dart about grabbing every last bit of mysis I put in the tank every couple of days.

 

[elvis]

I have a blood shrimp, cleaner shrimp and the peppermint shrimp. The peppermint only comes out after lights out. The other 2 are all over the place. Either picking at the fish or eating a few left overs. I haven't noticed anything unusual with the zo's. Hopefully this won't change. Thanks for the heads up so I can keep an eye on them.

E