Brackish Sea Anemone?

[zephi]

Has anyone heard or seen brackish sea anemones? well actually I'm not sure if it is or not. It could be a jellyfish.
My tank is in the higher end of the brackish salinity level.
I'm guessing this one got in from plants I recently introduced into the tank.
I've already posted this in the brackish forums but haven't got any responses yet, so hopefully I could get some here.

Here are some of the pictures I took today, one is when it was half open and the second one completely open.

It is very very small, under a cm in diameter, when its tentacles are outstretched. I've read the sticky post already about how to care for them, it's helpful, but it won't help me much.
It looks wonderful in my tank, I wish it could continue to grow in size. Any info for caring for small sea anemones.

 

[ben1987]

looks to me like a tiny tube anenome. not 100% though

 

[SkiFletch]

funky, never seen one of those before...

 

[zephi]

I've looked around for brackish anemones, but they aren't very common.... Anyway I fed it today, it happily took a goldfish flake I occasionally feed my fish and shrimp.

Here's a new picture, it's not as clear as the previous photos unfortunately. It's much fatter and rounder now.

 

[Lynden]

The good news here is that it may be an aiptasia of some sort, and therefore rather easy to feed and take care of. Just give it a small bit of meaty food (seafood) every few days.

The bad news is that of the anemones that are known to venture into brackish water, none grow very large. In fact, yours may even be a hydrozoan and not an anemone (which is a an anthozoan) at all; and if that's the case, it's size is probably already maxed out. Could also be a jellyfish polyp (and therefore a scyphozoan), but that seems unlikely.

 

[zephi]

The good news here is that it may be an aiptasia of some sort, and therefore rather easy to feed and take care of. Just give it a small bit of meaty food (seafood) every few days.

The bad news is that of the anemones that are known to venture into brackish water, none grow very large. In fact, yours may even be a hydrozoan and not an anemone (which is a an anthozoan) at all; and if that's the case, it's size is probably already maxed out. Could also be a jellyfish polyp (and therefore a scyphozoan), but that seems unlikely.

I really hope that it is an Aiptasia
Is there any way to find out which out of the 3 classes it could belong in? Maybe like, features to look out for as it grows? I've had hydrozoan in my tank before, they were very small (under 1mm in size) and grew in patches. I also have seen lots of tiny jellyfish in my tank, sizes were about 1.5mm (which now has completely disappeared).

 

[rabbut]

Strange, most people dread Aptasias in their tank. They spread like wild fire and sting fish, corals and mobile inverts to death... While it looks "similar" to an Aptasia, I don't think it is one...

 

[Lynden]

They are usually only a threat to very small fish, and since this is a brackish tank there is no corals I presume. I am among those who like aiptasia and majano anemones in the reef tank, though I am not above obliterating them in order to give the corals they are stinging a chance to catch up...

Also, aiptasia and majano in my tank don't seem as pestilent when compared to the goliath bubble tip anemones that reproduce almost as quickly. The bubble tips know as well as I do that they are in charge of my tank.

As far as I know there aren't many obvious ways to tell a tiny hydrozoan from a tiny anthozoan. One difference would be the total lack of a medusa stage in the latter. If you find tiny medusa in your tank one day, you probably have a hydrozoan. On the other hand, I would lean toward yours being an anthozoan due to it's size. Most hydrozoans, especially non-marine ones, grow all that large. Hydras, for instance, commonly stay under 1mm.

 

[zephi]

Strange, most people dread Aptasias in their tank. They spread like wild fire and sting fish, corals and mobile inverts to death... While it looks "similar" to an Aptasia, I don't think it is one...

I just never owned an anemone before, so it's interesting to have one in my tank.

 

[Lynden]

Aiptasia (and majano for that matter) are valued by some people, me included, for the diversity and interest they add to a tank.