Tridacna stroke? - 6/2/05 I have a Tridacna maxima in my 29gal reef that has been great for the few months I have had it. <Actually says very little unfortunately. It can take up to nine months for a healthy specimen to starve to death. A slow death indeed. This is the case with a lot of Tridacnid species as they don't get all their nutritional needs from light alone.> The past few days he has only opened on one side. <Weird.> I know that is hard to picture but imagine what a clam would look like after having a stroke. He is lying horizontal and the left side is colorful and looks as it has, but the right side is tucked away. <Maybe something irritating the mantle by way of stinging or picking at it?> All other corals, fish and inverts are doing fine. <Doesn't help me to further identify your situation any better without knowing more about your tank. Size is good but what about inhabitants (specifically fish and corals and other inverts), water chemistry, lighting, and any other thoughts that might come to mind. Thoroughness really goes a long way in diagnosis. Can't help much here except possible predation on the mantle or irritation from chemo reactants (i.e.. coral aggression through allelopathy) or again possible starvation.> Is this normal or is my clam in danger? <Very likely in danger> Thanks for your much appreciated help! <Please read through our articles and FAQ response to Tridacnid care. See if there are any questions/answers describing your situation. Thanks for being part of it all. ~Paul>

Clam question Hello there- My father says WetWebMedia has given him lots of great advice- I have a question about Tridacnid clams (purple/blue (not maxima)......I've had a couple for about a year or so, and they both died the other day, both within about 24 hours.  All I could see was what looked like clear snot, and what looked like pieces of sand in the mucus, .....the clams closed up, and they seemed to have a hole in the bottom of them......the only thing that seemed to be near the clams, were brown tiger tail cucumbers. Have you seen this before? Thanks for your help..... DaveB <Hello Dave, Have you fed your clams weekly?  Marine Snow is a good product to use.<<Uhh, not in all's opinion here. This product is a placebo IMO... has VERY little nutritional value>>  It's not necessary to feed daily, a once a week feeding should be enough. <<Barry Neigut suggests a minimum of 3 times per week... and NOT Marine Snow>> Also, do you change your bulbs on a yearly basis?  Clams do require strong light of the proper spectrum.  Just cause the light lights doesn't mean the full spectrum is still there.  Most clams will only do well under metal halide lighting. James (Salty Dog)>  

Clam exudation 3/27/03 Greetings!  I have a blue Tridacna maxima, about 5 inches below the surface of the water under a 175W MH with 40W of fluorescent actinic.  The clam is about two years old.  Recently I have noticed that in the evening, I see a very thin brown strand of  (I assume) Zooxanthellae algae coming out of the exhalant siphon.   <could be... sometimes they are expelled naturally in small packets, other times induced by stress (increase in light as with new bulbs or clarity as with water change or sudden use of carbon)> The clam is well extended and looks great.  Water parameters are great and unchanged, except that I recently (1 month ago) noticed that the pH was dropping to 8.00 during the night.  I slowly used Reef Buffer to raise the pH to about 8.45 during the day, dropping to about 8.30 at night.  Salinity is 1.025 and nitrites are zero, and nitrates are 5ppm.   <all good> I use PolyFilter and an Urchin Pro.  Is this algae discharge normal? thanks tom <likely no worries at all. Be mindful not to overfeed (at risk of clogging gills) with liquid supplements too. Best regards, Anthony>
Re: Clam exudation 3/27/03 Thanks for your response, Anthony.  I have been feeding liquid food, perhaps a little bit more than usual.  This afternoon I noticed some bleached spots on the mantle which weren't present this morning.  The mantle is open/out. <not good signs at all... and rules out coagulated food from overfeeding as the primary. Stress from a physical parameter is more likely now... the sudden influx of a larger than normal bit of freshwater perhaps for belated evap top-off? Dosing supplements in strong concentration near it at the top of the tank (sans dilution in sump or strong stream). Hmmm... many possibilities. Predation is more common in general but would not expectedly cause the bleach spots. Instead we are looking for stress or disease here. Perhaps a new fish or coral added recently without QT brought in a pathogen> Any suggestions? thanks, tom <watch nightly for predators, but otherwise do not disturb while evaluating water quality. A water change is usually helpful too (dilution of the unknown). Anthony>