accidently left lights on too long

[JamesJR]

I have had a 1 inch tridacna maxima in my tank for nearly a month now. It was showing fresh growth and good mantle extension until yesterday. I realized that I had accidently had my timer bypass switch on and my lights had been on for over 24 hours. The clam's mantle was withdrawn but the clam wasn't completely shut. When I walked up to the tank it responded to my presence by closing further. I am only using t-5 lighting. I am aware that it can be pretty serious for clams to get too much light. I am just wondering if anyone else has done anything this stupid and gotten away with it. I am feeling kind of restless and am dreading coming home.

[moliken]

james, i have never heard of clams getting too much light. in the wild they are sometimes exposed to direct sun at low tide, with no water on top of them. a 1 incher may have other probs. it may have had its calendar thrown off, or something else may be bothering it, but too much light is doubtful to me, esp w/t-5's in a 20 gal. is the maxi way at the top?
check your params recently?

[JamesJR]

Clams can definitely get too much light if they are not adapted to it. I remembered reading in Knop's book that changing the photoperiod can be bad for them. He even shows a picture of a clam he lost by leaving the lights on 2 hours longer than normal.

I guess what I was trying to wonder is if anyone has ever seen the same symptoms as I am just a little paranoid. I will let you know when I get home if I see if things have improved.

I tested yesterday and my values are always the same.
ammonia, nitrite 0 by salifert
Ca 420 by salifert
alk-runs a little high on salifert at 10.5
Magnesium 1300 by elos,
pH 8.2
SG 1.026 via thermo fisher calibrated hydrometer (I have used a friends refractometer on several occaisions and gotten good agreement).
Nitrate and phosphate are undetectable by Salifert
Temperature is always about 76-78.

I have a pair of clowns and I feed them regularly. I also feed my clam once a week with a tiny addition of a yeast culture.

[moliken]

i'm looking at pg 80 in knop's book, in which he discusses this death. it occurred in clams 'insufficient ability to shield it from ultra violet light...the condition develops slowly over a period of weeks or months during constant conditions of illumination" ; i don't think that's the case with yours. this clam he mentioned had this "pronounced central bleaching" from exposure and the 2 hour light lengthening killed it. later he says "unchecked exposure to light will kill the animal." i hope this interpretation is right, and again, i really doubt that a 24 hr light period one time did any harm. in addition, your clam has had a month to adapt to its lighting; this mistake shouldn't kill it. maybe a bit of bleaching, and i even doubt this. move it down if there's no improvement or find a different cause. got snails?

[a4twenty]

24hr light can be a problem for clams, often causing a spawning episode. i think this is due to stress caused from not getting a rest period but the clam should make a full recovery. after work, i'll have to take a quick look through my books / links / papers to find the article.


hope everything is still ok..........

[tahoe61]

Extended periods of light can be a problem for clams. Yes in the wild they are exposed to intense lighting but the lighting is effected by passing clouds, changes in tides and they only recieve approx. 12 hours with the most intense being at mid-day. Point is that the light they recieve in the wild varies greatly during the photoperiod.
The act of metabolism by the the zooanthellae, causes production of O2 and free radicals. Clams need a break from the light to decrease the levels of O2 and free radicals within their tissues.
If your can burn corals and inverts with a new replacement bulb, than 24 hours of constant light can be detrimental as well.

[JamesJR]

I made it home and the clam looks a lot better. This is the first time I've attempted a maxima this tiny and I am just trying to be very cautious.

[moliken]

very happy for you and the clam. they can be really stressful. i had one of those big poly maxis for 13 days. looked perfect and happy. dead the next morning.

[JamesJR]

Mine is an ORA gold maxima. So far so good.