doomed bottom dwellers?!

[fishdoc11]

My 75 gal sps tank was created with the idea of keeping clams as well as sps. So far I have tried 4 clams and all have followed the same patern before expiring. When I recieve them they do well for about a month and then slowly open less and less until they die at about 1.5 months from purchase. All clams were purchased from my local lps that keeps them in much less than adequate light. However all spent a fairly short time there and had seemingly healthy bysus (not torn,all attached well in my tank).Very close to the same thing has happened with two open brains and two ORA conchs. So any thing I have put on the bottom besides blue hermits, emerald crabs and sps frags have died(before you say anything about the crabs all except the last clam died before they were introduced). I have a healthy population of bristle worms and do suspect them. I also dose 1 tspn of strontium and 2 drops of Lugols a week and realize according to some people this may be a problem. Clams were 2 maximas,1 squamosa and 1 deresa ( tried last because of hardiness). All water parameters are good and calcium is maintained with daily additions of Kent A&B. If anyone sees a pattern here your input would be greatly aprechiated.
Thanks, Chris

 

[kmk2307]

Hey Chris,

Some people have a motto of "if you don't test for it, don't add it." Also, I have heard the addition of strontium and iodine is detrimental to clams. There is a thread in Dr. Ron's forum I recently saw about this. What is your water quality like? Do you feed a lot? Do you feed phytoplankton? You might want to start removing some of your bristle worms. You could probably give them to local reefers with new tanks that would be happy to recieve them.

Kevin

 

[fishdoc11]

Hey Kevin,
I recently have been reading alot more about testing for additives. I decided on my current routine through trial and error which was the thing to do a few years back. My routine works well for my corals at least. I listed the only things I have lost in over 2 years aside from 2 seriatopora frags( they just dont do very well in my tank, I have one now but it's growing very slow) and a green slimer that looked bad when I got it. Aside from these all of my corals do very well. I am planning on getting test kits though as this makes alot of sense. Aside from that my water tests as followsH=8.2-8.3,Alk=3.2-3.5,calcium=450-475,NO3<2.5,NO2,NH3andNH4=0,PO4<0.1,temp=76-79 winter,79-82 summer,SG=1.023-24.As far as DT's and stuff like that I don't add any. I tried DT's when I had the two Maxima's. The only thing it seemed to do was increase the level of algae ( thus the addition of the crabs ). I feed the tank fairly heavily and scrape the glass 2-3 times a week and currently am of the opinion that this is sufficient. This is another area where popular opinion seems to be changing. As far as the bristle worms I have tried to trap them with limited success. I must admit this limited success is probably due to my reluctance to reduce feeding in the tank much. I failed to mention the size of the clams before,Maximas 5" and 2.5", squamosa 2.5" and a 4" deresa.Thanks in advance for any more help and thanks Kevin for replying.
Chris

 

[gwrulzmylife]

just watching this thread, so I don't have the same problem

 

[fishdoc11]

Anybody else have any ideas?

 

[piercho]

I think that you can illiminate not enough light as a problem, based on your tank description. So look at the rest of possible causes and try to eliminate them:

1) Cumulative stress. Your clams died very quickly and that would make this the main thing I'd look at. From ocean to distributor to retailer to you the clam endures sequential changes in lighting and water chemistry. For instance, most pet stores keep their SG and temp very low at around 1.020 @ 75F, while the clams are accustumed to environments more like 1.026 @ 81F. The clams have to survive on energy reserves for days to weeks during this process, and compensate for radical changes in water chemistry and lighting, and sometimes it is just too much for them. I'd consider purchasing the clams from a retailer (or etailer) who specializes in Tridacna and who has specialized tanks for holding them for acclimation after they arrive from the distributor. I used clamsdirect.com but there must be reputable dealers in the southeast where you live.

2) Lack of food. There is live plankton, inert refridgerated or frozen plankton, and yeast-based additives. These all work, probably with varying effectiveness, to provide food for clams. These are expecially important while the clams are newly arrived and adjusting to new conditions. Larger clams that are acclimated may not need them. I kept a 3" Squamosa in a completely bare 10G under PC for 2 months while treating it for severe mantle pinching disease before moving it to the main tank. During this time it was fed DT's refriderated live plankton and had measurable shell growth. I'm not convinced feeding is needed over the long term but IMO it is essential for new, sick, or small clams.

3) Disease and parasites. The most important ones to be aware of are mantle pinching condition and minute parasitic snails that feed on the mantle. The parastic snails could be resident in your system, hosting on your grazing snails. There are also boring predatory snails but it does not sound like your previous clams died from a predatory attack. If the retraction of the mantle into the shell started with a small area of pinched mantle and progressed, that describes mantle pinching condition (disease?). My opinion is that the worms that you have are not predatory on Tridacna, but people have different opinions and experiences on this than me.

4) Water quality and water parameters. This is a big topic but if you have animals declining and you can't account for why, it's time to suspect that your water has gone south. Or that you have good water but not within the allowable temp, pH, or salinity limits for the clams.

That's all I can think of. If you haven't read it, I'd read Knop's book "Giant Clams" before trying any more. I'd also research and consider the 30 minute FW dip described by Minh Nguyen for all new clams as a preventative for mantle pinching disease and to kill off most most small animals resident on the shell or mantle surface. I 'm not an expert in clams and I would seek out more advise from people more experienced than me before trying them again. Good luck.

 

[fishdoc11]

Piercho, Thanks for your in depth response. Stress is probably a factor. I just figured after a couple of weeks I was ok but apparently not. I have recently figured out ( through selling frags to this lfs) that the manager of the salt dept. where I purchased these clams pretty much floats stuff and in it goes, nothing for the change in SG. I have thought about Clams direct but would hate to order 4-5 clams ( enough to make shipping worth it) and have them die because the problem was'nt fixed. I have read Knop's book twice and I think it is excellent. I have also read other stuff on clams by Tullock, Sprung and Delbeek and others. As far as pyramidellid snails I have never seen any and have also found no evidence of boring in the shells. I'm ceartain my H2O is fine as I have many sps and other corals and fish growing like weeds. The freshwater dip is new to me and I will have to read up on it. Thanks again for your suggestions. Maybe I'll get this figured out one day.
Chris

 

[joe123987]

Fishdoc

I think you will find this article interesting:

http://www.animalnetwork.com/fish2/aqfm/1999/july/features/2/default.asp

I now run my 2 x 400w MH + 2 x 96w super actinics for 13 hours a day. Clams, SPS and LPS (everything) in my tank has been doing much better since I increased my light time. I also feed DTs every other day. For small clams (less than 4") you need both. Bigger than 4" - you still need both but more reliance on light and less on DTs.

Also, please read Dr Ron's articles on dosing Iodine and Strotium with clams.

Lack of Light and suplemental feeding as well as dosing may contribute to their early demise.