sudden clam death???

[sharkdude]

I had a 2-3 inch blue crocea, a 5-6 inch blue crocea and a golden/brown 4-5 inch crocea on rocks about 20 inches from surface on the left side of my 120 directly under 250w 10k ushio and vho actinics.

The larger blue I had for about 3 months, the smaller blue about 4-5 months and the golden about 1.5 months.

A week before christmas, the large blue started gaping and then was dead and completely eaten in about 3 days. The other two clams seemed fine.

Then a week ago, the small blue started gaping and was dead within 2 days. The golden/brown followed a few days later.

I did not change a thing with the tank and all other corals seemed fine (with exception of a small zoanthid colony dieing off in same time period but all other zoos ok). I dosed normal amounts of kalkwasser only. It would be hard to pinpoint any specific type of chemical warfare as I have mixed reef, mostly softies but some sps.

I do have a rock beauty angel, but he really did not seem to be bothering the clams and they were opening just fine.

I want to fix the problem and or my practices before I try another clam.

anyone have any ideas on what may have caused this relatively sudden calm death?

 

[rvitko]

The rock beauty is a suspect. You could have a mantis shrimp, a bacterial disease or a pyramid infestation. Look very closely at the clams, inspect for small white snails. Pick up a copy of Giant Clams by Daniel Knop.

 

[sharkdude]

Thanks for reply Roger.

I doubt I have a mantis as I haven't added any new rock in quite a while and I still have all my fish, snails and hermits.

The Rock Beauty used to pick but I haven't seen him do it in quite a while.

I am familiar with the snails; I had them before on a derasa. They didn't seem to kill the clam as I would periodically scrub them off. I did not notice any pyramid snails on any of my clams in this instance.

so, based on your speculations, that leaves bacterial infection?
Are there clam specific bacteria that would act this quickly?

 

[rvitko]

Well, you could have a multitude of things working together to kill the clams. Suppose you have a few pyramids- no they aren't immediate killers but they are like aphids on a tree- they slowly suck the life out of it and set it up for infection. The angel is an opportunist, if your clams are stressed and excreting slime the angel will pick on them. Now, they are really weak and annoyed. Most bacterial infections follow a rapid course in clams- especially in warmer waters. The first noticable sign will be a not fully open mantle or a curled mantle. This may happen for two days and then it will likely be dead. The best treatment is a freshwater dip of about 1-2minutes. The Knop book shows some photos and describes this in more detail. I have had a 50% success ratio wit this method. My honest opinion is it is in one way or another attributable to pyramid snails. Yoy might be astounded to see how many can live unnoticed in the scutes and near the bysis. I don't think it is possible to successfully keep clams with pyramids. My advice is get a six line wrasse and wait a year and try again.