Huuuge Mushroom, how big?? (Pic)

So I have this ginormous green mushroom in my tank, it's a monster. Fully opened and spread out I bet it's like a foot in diameter. How big can a mushroom get? I've never seen one this big & it grew at such a fast rate.

I call it Godzilla:

 

I'm never good at ids, but looks like an elephant ear? If so, certainly can get bigger than a foot. I'm not sure the exact size, but 18"+ for sure. Can eat fish too.

 

Godzilla is right. That is a beaut. Looks like 15" is not uncommon. Be careful with small fish. They may be dinner.

Rhodactis mussoides
Elephant Ear Mushroom, Rhodactis mussoides, Mushroom Coral Information and Corallimorph Pictures

 

I was thinking that it could easily get larger then 18" depending on the species.

 

really, I've never heard of an elephant ear, how can I tell if it truly is? It has a large stalk on it, I don't think it's ever attempted to eat any of my fish. Is there just a harmless mushroom that can grow this large?

 

Elephant ears (aka amplexidiscus) are usually harmless, but can eat some unsuspecting, small fish. Some rhodactis can get close in size, but that looks doesn't really look like a rhodactis to me, more like an amplexidiscus. FWIW anyways, of course as mentioned, I'm not always great with ids.

 

Thanks everyone for your input, this hobby is so amazing as you learn new things all the time. The reason I'm concerned is I have had many smaller fish go missing days after I got them and I'm wondering if there is a connection.

It just seems odd that this is a fish eater, I don't see its mouth and the stalk looks so "mushroom like". But I could not believe how fast this thing has grown, quadrupled in a few months time. I'm thinking maybe it's eating fish and growing??

If I find it truly is a threat to small fish I will remove it, I have my beloved mandarin and a few other small guys I wouldn't want to lose.

 

It is most likely a possible culprit in your fish loss. Elephant Ear and fuzzy mushrooms get huge and are known fish eaters.

 

Thats a huge mushroom! I have a green hairy mushroom that is probably at least 7" in diameter and growing fast too.I knew they could sting,but was unaware myself that they could eat fish and/or grow that huge.I may need to reconsider rehoming mine.

 

They trap their prey by folding up around them. Then they spill their guts to dissolve the prey and suck em down