Hitchhiker Anemone?

[andy]

Noticed this fellow on a zoa colony rock (the one I got from Michael7979 last summer):

 

I'm thinking it is a Pseudocorynactis caribbaeorum, any other ideas? Also good-guy or bad-guy? I've read mixed reviews. The zoas don't seem to mind, the hitchhikers (there's actually two of them, the other is on the back side of the colony rock and hard to get a pic of) only come out at night when the zoas are 'sleeping'.

 

Mike, have you seen any others in your tank?

[DChemist]

I have one that lives in the sand bed and only comes out at night. Appears harmless- but then again, he's not living real close to anything I really value.

[Michael7979]

I no longer have any zoas in my tank anymore. I have never seen one that matches that in my tank. Sorry I can't be of more help.

 

But I never had a problem with any of my zoas before either.

[DChemist]

From Advanced Aquarist... http://www.advancedaquarist.com/issues/oct2002/invert.htm

 

Pseudocorynactis

Pseudocorynactis spp. are like Corynactis but are much larger (to about six inches (15 cm) diameter, and usually not colonial. They also reproduce by fission, but it is unusual to find more than about six clones together as a group. The so-called orange ball anemones that can be observed on coral reefs at night are Pseudocorynactis spp. The column varies in color from cryptic shades of brown to orange, red and magenta. The tips of the tentacles are commonly bright orange, but they can also be white. These tentacle tips are extremely sticky, like flypaper, due to the presence of powerful nematocysts. This fact makes the larger species from the Indo Pacific region unsuitable for aquariums housing fishes, which they readily capture. They also can catch mobile invertebrates such as shrimps and snails, and sometimes "attack" sessile invertebrates growing on adjacent rocks, enveloping them in the gastric cavity through a widely opened mouth. Pseudocorynactis spp. can be fed daily, but only require twice weekly feeding to keep them healthy. If they are not fed frequently enough, they shrink. There is a marked behavioral difference between the common Caribbean and Indo-Pacific species.

The Caribbean species, Pseudocorynactis caribbaeorum mainly opens its tentacles at night, and closes rapidly when it senses light. The Indo-Pacific species remains open both day and night, and is not sensitive to light. The presence of food smells (dissolved amino acids) in the water stimulates either species to open up and extend the tentacles, and the caribbean species can be trained to open in the light by feeding it during daylight hours. The mechanism for its apparent memory is not known.

Whether you have a large reef aquarium or a simple small aquarium, any of the corallimorphs can be easily maintained and enjoyed for decades.

[DChemist]

And from Wet Web Media... http://www.wetwebmedia.com/shroomfaq3.htm

 

Ball Corallimorph - Pseudocornyactis 11/17/03

I have two questions for the knowledgeable crew of WWM -

if you can spare the time

1. A while back I found this cutesy little hitchhiker on my live rock (photo included). Can you tell what it is? The only possibility I came up with is a Corallimorpharian,

Pseudocorynactis sp. (although in the pictures the colors are

different).

This worries me a little, because Julian Sprung says in his book that the Indo-Pacific Pseudocorynactis will grow big and eat small fishes/mobile inverts (!)

I like the little fellow, but if he's shaping to be a fish eater, then I'd better nip him in the bud, so to speak. So it would be helpful if you could confirm - or refute - my identification.

2. I know you guys are against mixing different groups of corals (SPS, LPS, zoanthids etc)

- and it makes perfect sense when we're talking, say, about tabletop Acropora from the reef front being housed together with mushroom corals that naturally live in calmer, deeper waters.

But how about species from the same habitat? Say, Montipora

digitata and soft corals - all lagoon dwellers? Wouldn't it be natural to put them together?

I am asking because I have softies at the moment (the

beginner's obvious choice), but I would love to try Montipora one day - and then, barring a total re-haul of the tank, it would find itself among soft corals... What is your opinion of that combination?

All the best Anka from Poland (a dedicated fan of your great site )

[andy]

Thanks Darren, good info. I'll let them stick around and keep an eye on them. If they get too rowdy, out they'll go.

[DChemist]

I reseached it because I've been meaning to learn more about the little guy in my tank (and to be helpful, of course). I think I may start feeding mine to see how big it will grow.

[andy]

Wet Web makes them sound pretty threatening... feed it from a distance, it'd suck to get dragged into your tank and consumed.