As I went to look at my tank this morning I noticed my Deresa clam in a terrible state. It has basically shrunk to a quater it's size within it's shell. It is gaping open and looks like I will have to remove it before it pollutes.
Here's the history:
I have 5 clams in the tank. 2 crocea, 2 maxima, 1 dersa. The deresa was the last clam that I added. All my other clams have been putting on good shell growth. I know deresa are generally considered the easiest clam so I didn't think I would have any problems. Tank is lit by 2x150W 10,000K. I bought the dersa 6 months ago and placed it on the bottom of the tank on the sandbed. Clam seemed happy in this position. After a few months I noticed the colour of the clam was browner with the irridiscent edges going. After looking in Knops book I decided this was probably due to not enough light. So I moved the clam slightly so it was on the bottom under the light. After awhile the clam was colouring up again and I thought all was OK.
Anyway after a few more months had passed I was still not totally happy as the clam was not putting on any shell growth. All other clams and SPS were growing great, yet the deresa which should be fastest growing wasn't. Tank has a Ca reactor and Limewater doser so calcium concentration is alway up in the 400s with alk around 3mEq/L. After a while longer I noticed a clearing up of mantle after referring to Knop i concluded maybe a lack of nitrate. Well I don't want to go round dumping Ammonium Nitrate in my tank so I decided to up my phyto feeding to everyday. I thought this was the clam will either decide to feed on the phyto or it will go on to help provide more nitrate for the clam zoox.
Clam has remained this way opening as normal with just generalized bleaching. The clam looked healthy yesterday (although still no shell growth) but today it is a quarter of it's size in the shell.
My conclusion is that the clam has never adapted to my tank be it light intensity, spectrum or lack of nutrients the clam must not have ever had enough energy to put on new shell growth. So maybe it's basically just had enough and run out of energy reserves?
Here's the history:
I have 5 clams in the tank. 2 crocea, 2 maxima, 1 dersa. The deresa was the last clam that I added. All my other clams have been putting on good shell growth. I know deresa are generally considered the easiest clam so I didn't think I would have any problems. Tank is lit by 2x150W 10,000K. I bought the dersa 6 months ago and placed it on the bottom of the tank on the sandbed. Clam seemed happy in this position. After a few months I noticed the colour of the clam was browner with the irridiscent edges going. After looking in Knops book I decided this was probably due to not enough light. So I moved the clam slightly so it was on the bottom under the light. After awhile the clam was colouring up again and I thought all was OK.
Anyway after a few more months had passed I was still not totally happy as the clam was not putting on any shell growth. All other clams and SPS were growing great, yet the deresa which should be fastest growing wasn't. Tank has a Ca reactor and Limewater doser so calcium concentration is alway up in the 400s with alk around 3mEq/L. After a while longer I noticed a clearing up of mantle after referring to Knop i concluded maybe a lack of nitrate. Well I don't want to go round dumping Ammonium Nitrate in my tank so I decided to up my phyto feeding to everyday. I thought this was the clam will either decide to feed on the phyto or it will go on to help provide more nitrate for the clam zoox.
Clam has remained this way opening as normal with just generalized bleaching. The clam looked healthy yesterday (although still no shell growth) but today it is a quarter of it's size in the shell.
My conclusion is that the clam has never adapted to my tank be it light intensity, spectrum or lack of nutrients the clam must not have ever had enough energy to put on new shell growth. So maybe it's basically just had enough and run out of energy reserves?
