Giant cup mushroom?

[SeaCucumberFan]

I've had it for like half a year, but I have no idea what it is. It feels very soft. I thought it was toadstool until I saw one of those really big mushrooms. I'll post another pic if needed. https://drive.google.com/file/d/0B0CfL8c-l0BZYUk4NldiN1gzTWM/view?usp=drivesdk

 

[Apercula]

It could be, does it have a clear ring around the outer rim where there are no tentacles?
Here is a picture of my old one, the ring is very noticeable, this mushroom was over 18 inches in diameter at this picture.


I moved it and a few small bits tore off the foot. These two are about 4inches in diameter 6months or so later, the ring is visible on them too even that much smaller.


The large one ate the male of a maroon clown pair that I had in a frag tank after I removed it from my display.

 

[SeaCucumberFan]

Yes! It has a clear ring without tentacles. Do they eat fish? New question: why does my LFS only sell gray ones

 

[Apercula]

Yes, they are fish eaters, especially small fish that like a host, like clowns. The mushroom will close up slowly, more active fish will flee, but clowns don't seem to realize they are being trapped until it is too late. Other fish that could be in danger would be stuff like hawkfish, gobies and blennies that like to perch on stuff.



My big one closed up in feeding mode.

 

[Apercula]

I cant answer the color question, I bought the big one online as a purple, it was more a golden brown, the small ones were frags of the big one and are more of a purple brown. I expect it has a lot to do with light spectrum over time.

 

[SeaCucumberFan]

Yours are huge!! Mine is only around maybe 15cm across when fully extended. The ones at my LFS are super huge, I've seen one maybe close to 2 feet long.

 

[Apercula]

Yeah, it didn't take me long at all to realize an 18inch in diameter mushroom was too big for a 75g tank.

 

[SeaCucumberFan]

Wooooooaaaaaaaah. You should frag it up into 100 pieces and then sell them. Is the green one a mushroom too? And MOTHER OF GOD IS THAT A GIANT AIPTASIA

 

[Apercula]

Under the drain to our left is a small long tentacle anemone, I had thought it dead because it disappeared for 4 months into the rocks. When it was gone I bought the green haddoni anemone, and the mushroom, which was listed by the seller as being 12 inches when it was really 18. This tank was up from 2007 to 2012. I had a major tank loss caused by heat in 2011 then took it down completely in 2012 when I moved.

 

[Apercula]

The lta when it first crawled back out of the rockwork.


With the clown about the same time as the fts above.


Up close of the haddoni.


The lta after the haddoni had been traded away, and it moved to a more traditional sand location.

 

[SeaCucumberFan]

Ok thanks for the info I have confirmed it is a gray giant cup mushroom