My squamosa clam is no more

[Cliff]

I’m not too sure what happened to my clam, but he died today. He was in the tank for just over 3 weeks. He seamed fine right up until today. When my wife checked the tank at lunch time, everything looked OK to her. Later in the afternoon, the clam was really slow to react to anything else in the tank (as compared to his normal behaviour) and turned lifeless about 4 hours ago. All other corals and fish are doing OK. My brain coral is still a little stressed from being shipped to our SW LFS and then added to his new home all this past weekend, but he is eating very well. I have been supplementing the water with food additives for filter feeders as my tank has only been cycled for about 3 months. Other than one bristle worm sighting a few days ago, I haven’t seen anything in the tank that would potentially be harmful for a claim.

The only thing that has changed in the tank is the addition of the brain coral and a lighting up-grade from a 4 bulb HOT5 fixture to a 8 bulb HOT5 fixture (I’m only using 6 of the 8 blubs at any given point in time). The claim was placed about ½ of the way to the top of the 90 gallon tank on some live rock. Before today, he was firmly attached there. He wasn’t an old clam, only about 4” in length.

Water parameters:
Ammonia, phosphates and nitrites - all 0
Nitrate – 1 to 1.5 ppm
Dkh – 10.6
Cal – 400
PH 8.2

I am not dosing anything, just weekly 10% water changes with RO water and reef crystals

My first thoughts are that I added a filter feeder to early to the tank and the food additives were not enough to keep the claim happy

I would be interested in any thoughts you might have as to what might have happened

[ILuvMyGoldBarb]

With sufficient lighting, your clam shouldn't have died due to lack of feeding. Feeding is not crucial for these creatures when lighting is sufficient. I have a Crocea in my 37 that has been there for almost a full year.
My guess is the age and stability of the tank is not yet what it should be for a clam. There is another possibility, the clam may have had Pyriamid snails. These will devastate a clam in captivity.

Just a couple other pieces of info for you; Squamosa clams are bottom dwellers and should be placed on the sand. In addition to that, they are one of the less light demanding of the Tridacnids.

[Cliff]

Thanks Goldbard.

By pyriamid snails are you referring to these guys



Or are you referring to pyramidellids

[ILuvMyGoldBarb]

No, that is an Astrea snail. Many call them Pyramid snails, but these parasites are really Pyramidellids. They punch holes in the clams tissue and suck the blood. Not a good thing.
The feeding may have been an issue for your clam as they depend heavily on feeding up to about 4" in size. After that they are less dependent. If your clam was just under 4" then it may have actually needed more food.

[gadget228]

I don't know anything about clams so I won't be any help but wanted to say sorry for your loss...

[Cliff]

Thanks again Goldbarb. Looks like I was editing my second post while you were replying. I havn't seen any of pyramidllids yet in the tank, but I'll keep an eye open for them.

Thanks Gadget228.

[labnjab]

How big was the clam? Small clams have a high mortality rate, even ora ones. I won't buy ones anymore unless its over 4 inches.

As far as feeding goes, we had a long discussion on this on my local reef club. Spot feeding can actually lead to their demise as it can clog up their gills if you feed too much. Its best to feed the whole tank something like phytofeast. I personally don't feed our clams and they are growing very fast.

[Cliff]

Labnjab: the claim was about 4" (give or take a 1/4"). I was adding the food suppliments into the water as I also read a lot of information that spot feeding is really bad for a clam, but didn't understand why it was bad until I read your post (thanks). With 0 phosphates and very low nitrates, I was worried about the clam and corals that are not easy to spot feed (like leathers) not getting enough food.

I didn't realize some clams have a high mortality rate. I've talked with a bunch of SW Reef owners that also frequent our SW LFS and they all have clams and it seams that only the clams that are 4 to 6 years old past on like mine did. But I think that might be because our SW LFS typically only stocks clams in the 5 to 6" size range so they are more hardy once reaching that size (as Goldbarb has already stated).

I'm starting to think it was a bad idea to add a smaller clam to a new tank. I should have got a bigger one or just waited a few more months.

[ILuvMyGoldBarb]

Something else to keep in mind. Phosphates are not a bad thing for Tridacnids. These clams use the phosphates in their environment, in fact, they need a small amount. Much of the reason people see such a high mortality rate on their clams is because they keep their reef environment too sterile. That's not to say you should have a phosphate reading in your tests, but they do need some source of it to use up. Phosphate reactors are actually not a good thing for Tridacnids.
Clams are also used by some hobbyists to help keep their water clean. I have seen a tank with 6-8 Crocea clams in it and the water was pristine. The clams are excellent at keeping phosphates down and keeping particulate matter to a minimum in the tank as well.

[Cliff]

Thanks Goldbarb.

I knew they needed a little nitrate and phosphates (which is why I supplimented), didn't realize they were capable of taking up that much phosphate.