Clownfish disappeared! Ideas?

[Amphiprionocellaris]

Greetings.
I have (or maybe I should say "had") a mated pair of ocellaris in my 75 reef, both looking very healthy. However, yesterday, the female mysteriously disappeared. I'm assuming it's dead, but I have not been able to find any trace of a body (or living clownfish). Does anyone know of anything like this? Heart attack, maybe? I'm perplexed; the clown showed no signs of anything but perfect health.

All water params that I test (NH4, NO3, NO2, Ca, alk.) are nearly perfect (and way within acceptable). I purchased both clowns about a year and a half ago, both are CB. Everything else in the tank is doing fine besides the mushrooms, which had a massive die-off a couple of months ago. They might have released something into the water, but I figured the corals would be the first to die from any tank condition that would kill a clown.

Also, how long would you recommend waiting before replacement? I don't want to potentially infect any other clowns, yet I have no idea for a cause of death.

Any help is appreciated.

[GettingFiesty]

Do you have a tight fitting lid, could she have jumped?

[Amphiprionocellaris]

The lid has some gaps in it, but I checked the area around the tank, and there's nothing. I'm guessing scavengers found any body before I could. I'm just perplexed as to cause of death, and whether or not the tank is safe to add a replacement (my last chance for an LFS run for a while is very soon, and I wonder whether or not I should consider getting one then). The least I want to know is whether this is a freak occurence or some sort of disease.
Any other ideas? Just brainstorming, so any suggestion is more than welcome.

[GettingFiesty]

A disease sounds weird considering how long you have had them and how long your tank has been stable. I hope somebody else jumps in soon--although my Angel died back behind my rocks and I never did see any remains--beyond the incredible phosphate spike that is.

[Dolfan0925]

what all is in your tank? I have heard of frilly mushrooms that ate clowns, and brittle stars.

[Amphiprionocellaris]

Actually, the frilly mushrooms were the ones that had the die-off. There is one very large brittle star in there, but I don't think it was large enough to eat her (she was fairly large, plus she slept in the anemone [S. haddoni] overnight).

Like I said, all suggestions are welcome.

[GettingFiesty]

You are not going to believe this. Came downstairs this morning and can't find my perc anywhere. Came home fromwork and checked the overflows, the sump, everything and he is just missing! I am so bummed! I do have some small hermits and one arrow, but I don't think they got him.

[Atticus]

Haddoni could have eaten her... I would not be afraid to add a new clown that issue you are going to run into it pairing the new clown and the male that will now want to be female. Get a small one and QT it for no less than 4 weeks and you should be fine.