Crocea help

[Mark G]

Help! I purchased a beautiful crocea six days ago from a LFS. The light intensity at the LFS was marginal at best. I placed the clam in the sand bed of my aquarium and all seemed well. My current lighting system includes two 175 Watt MH and 2 110 Watt VHO actinics. The top of the sand bed is 21 inches from the glass on the bottom of the hood. I am planning to upgrade to 250 Watt MH soon. I was surprised the clam always seemed to position itself in the sand at about a 45 degree angle so that the mantle was facing slightly away from the light. About two days ago I began to notice some loss of pigment on the edges of the mantle that was closest to the light. Today I noticed bleaching around the incurrent and the excurrent siphon openings. Is this condition being caused by insufficient lighting or from a sudden exposure to a more intense lighting? Could trauma or stress from shipping be a factor? This is such a beautiful creature and I would hate to be responsible for it's death. Any help would be greatly appreciated. Thanks.

 

[MiNdErAsR]

<img src="http://www.reefcentral.com/images/welcome.gif"><br><b><i><font size="4" color="blue">To Reef Central</b></i></font>

It could be light shock, as you mentioned LFS lighting was marginal at best. Try relocating further from the halide, gradually bringing it back into full light. Of course it may have been affected by something at the LFS and didn't show any signs until now.

HTH.

 

[toptank]

I think Jim hit it on the head. It could be a form of central bleaching cause by sudden increased lighting.

IMO I would try what Jim has suggested first.

Keep us informed please.

Barry

 

[Mark G]

Thank you for the advice. I can't move the clam any lower in the tank so I will move it over to one of the sides. Hopefully the light there will be less intense than it was in the center. I'll let you know in a couple of days how it is doing.

 

[toptank]

Can you place a small piece of frosted glass over the top of the tank so you can filter the light. I have done that when I acclimate my clams.


Barry

 

[Mark G]

I've moved the clam over to the side and have placed the textured-glass cover that came with the tank over the light. Should I wait until the bleached areas have resolved before I begin increasing light intensity? Thanks.

 

[toptank]

Mark I would watch him for a few days to see how he look and then remove the glass cover as he MAY have lost some of his symbiotic algae. You have different types of bleaching so it is really hard to say at this point.

Barry

 

[jim norris]

Mark,
How is the clam doing? IMO the crocea like all clams filter feeds. If a crocea who's filtering member (which is the finest of all giant clams) Gets stopped up he cannot filter he bleaches and dies. A crocea on a fine sand bottom often sucums to this. A crocea more so that any clam needs to be on a rock away from and sand.
Jim

 

[Mark G]

After two days under the textured glass the clam appears to be no worse. Here is my plan. I will remove the textured glass tomorrow but leave the clam in the corner of the tank. This clam does tend to blow a lot of sand around so I will follow Jim's advice and try to find a flat piece of rock to sit him on tomorrow as well. In two days, I will move the clam to the more intensely lit center of the tank. Two days after that, I will move him up onto the rock about half-way up. If all goes well, I will then upgrade my MH's from 175 to 250 Watt.

 

[Mark G]

Thank you everyone for your great advice. The clam is looking much better and has happily attached itself to a nice flat rock.

 

[jim norris]

Mark,
That is GREAT news! Keep us updated.
Jim

 

[toptank]

Mark, glad to hear the good news.

I have a few Crocea and haven't had any problems but just be careful if the sand. My biggest one is 6 1/2" .

Barry