Clam ID and advice

[LovesDogs_CatsRokay]

I got this clam back at the end of September, the LFS said he was a squamosa so I put him on the sand bed. For the first month or two he wasbut the last few weeks he doesn’t seem to open much. My Bella goby dumped a bunch of sand on him and since then he’s been staying closed. I’m not sure if he’s just avoiding sand or if something else is going on. I’m also now wondering if it’s a derasa clam not a squamosa, and if so does it need more light? I also have a maxima in the tank that is up higher on the rocks than the goby ventures and it is doing great.

Here is a pic of when I got him and one of how he looks now.

 

[DenverSaltyFarm]

that is for sure a derasa clam and they do need higher lighting. im not seeing any fresh shell growth which is not a good thing and there could be more issues than just the lighting. when you bought it did it have any new shell growth?

 

[Vette67]

Looks like a derasa to me. Yeah, it isn't opening much. I have noticed that 9 times out of 10, when mine starts to not open, it is because of high alk. Do you know where yours is at? My derasa doesn’t like alk above about 9.0. I was adding too much kalkwasser before, which was causing my alkalinity to spike. I have cut back dosing that and my clam is much happier. That is, if you are providing enough light. They like lots of light.

The issue with alk has been something I noticed in my tank, that may be worth looking into for you. I wouldn’t think it would have anything to do with a little sand. Here’s mine opening up as much as it can for the light. And since I got this one back in February, it has about an inch and a half of new shell growth. They grow quick in the right conditions.

 

[LovesDogs_CatsRokay]

that is for sure a derasa clam and they do need higher lighting. im not seeing any fresh shell growth which is not a good thing and there could be more issues than just the lighting. when you bought it did it have any new shell growth?

It did have new growth and continued to grow at first. It had about 1/8 inch of white shell all around at one point. Maybe a little more. A couple days ago I saw a tiny bit of white edge in a couple spots but not nearly as much as it did have. It’s foot is attached to glass through the sand. If it want to move it up higher how do I go about removing it?

 

[LovesDogs_CatsRokay]

Looks like a derasa to me. Yeah, it isn't opening much. I have noticed that 9 times out of 10, when mine starts to not open, it is because of high alk. Do you know where yours is at? My derasa doesn’t like alk above about 9.0. I was adding too much kalkwasser before, which was causing my alkalinity to spike. I have cut back dosing that and my clam is much happier. That is, if you are providing enough light. They like lots of light.

The issue with alk has been something I noticed in my tank, that may be worth looking into for you. I wouldn’t think it would have anything to do with a little sand. Here’s mine opening up as much as it can for the light. And since I got this one back in February, it has about an inch and a half of new shell growth. They grow quick in the right conditions.

I keep my alk around 8.2. If it’s not getting enough light would that cause it close up?

 

[vetteguy53081]

Here are a few things you must know and follow with clams in general

Lighting is important for overall health
Feed Phytoplankton daily
PH not to exceed 8.3
Salinity not to exceed 1.025
Temp not to exceed 80 degrees
Alk Not to exceed 9
Calcium not to exceed 450

Also inspect occasionally for any crabs or tulip looking Pyramid snails

Pyramids:

 

[Vette67]

It did have new growth and continued to grow at first. It had about 1/8 inch of white shell all around at one point. Maybe a little more. A couple days ago I saw a tiny bit of white edge in a couple spots but not nearly as much as it did have. It’s foot is attached to glass through the sand. If it want to move it up higher how do I go about removing it?

Well that’s interesting. Derasa clams do not have a byssal foot. I can move mine whenever I want. It occasionally wanders when it closes too forcefully, so I have to move it back where I want it. But I keep mine on the sand because it cannot anchor itself to a rock.

I would only be guessing about light. I have not personally experienced one in low light. I would imagine it would stop opening as much, but I’m only guessing. I have been running metal halides since 2002, and I have never measured my PAR, so I can’t tell you how much mine gets. But if I had to guess, it is under a 250 watt bulb, and I would think it is somewhere around 300 or so.

Hope that helps.

 

[LovesDogs_CatsRokay]

Well that’s interesting. Derasa clams do not have a byssal foot. I can move mine whenever I want. It occasionally wanders when it closes too forcefully, so I have to move it back where I want it. But I keep mine on the sand because it cannot anchor itself to a rock.

I would only be guessing about light. I have not personally experienced one in low light. I would imagine it would stop opening as much, but I’m only guessing. I have been running metal halides since 2002, and I have never measured my PAR, so I can’t tell you how much mine gets. But if I had to guess, it is under a 250 watt bulb, and I would think it is somewhere around 300 or so.

Hope that helps.

This one is definitely stuck to the glass.

 

[LovesDogs_CatsRokay]

I got a pic from a different angle. It looks like the one side still has the new white shell. You can see I’m having cyano issues. Don’t know if that would irritate it? I just verified the rest of my parameters, PO4 is 0.08,, NO3 is 2, sg is 1.025, calcium is a little low at 390.

 

[OrionN]

Well that’s interesting. Derasa clams do not have a byssal foot. I can move mine whenever I want. It occasionally wanders when it closes too forcefully, so I have to move it back where I want it. But I keep mine on the sand because it cannot anchor itself to a rock.

.....

It is a Derasa.
All clams have byssus gland and have thread to attach to a hard surface when young. As they get older, larger and heavier, the byssus thread no longer used in Gigas, Derasa and Squamosa. They rely on their massive weight to stay stable.

OP need to make sure the Derasa have plenty of light and good level of Ca and Alkalinity, and nothing bother him, not Parasitic snails of fish or other animals. Also need to ID if it has Pinch mantel disease
Good luck.

 

[LovesDogs_CatsRokay]

It is a Derasa.
All clams have byssus gland and have thread to attach to a hard surface when young. As they get older, larger and heavier, the byssus thread no longer used in Gigas, Derasa and Squamosa. They rely on their massive weight to stay stable.

OP need to make sure the Derasa have plenty of light and good level of Ca and Alkalinity, and nothing bother him, not Parasitic snails of fish or other animals. Also need to ID if it has Pinch mantel disease
Good luck.

I looked overnight for pyramid snails and didn’t see any but since it’s attached I can’t pick it up and look at the bottom. Would they only be on the bottom?

 

[SMSREEF]

Do you have measurable nitrate in the tank?

My first guess is that nitrate is too low. The dinoflagellates they have in the mantle need nitrate or ammonium. It may not have enough and is not opening fully to partially shade the mantle.

Second guess irritation from the goby dropping sand on it.

 

[LovesDogs_CatsRokay]

Do you have measurable nitrate in the tank?

My first guess is that nitrate is too low. The dinoflagellates they have in the mantle need nitrate or ammonium. It may not have enough and is not opening fully to partially shade the mantle.

Second guess irritation from the goby dropping sand on it.

Nitrate is at 2ppm. I tested last night.

 

[Vette67]

It is a Derasa.
All clams have byssus gland and have thread to attach to a hard surface when young. As they get older, larger and heavier, the byssus thread no longer used in Gigas, Derasa and Squamosa. They rely on their massive weight to stay stable.

Thanks for the correction. Now I know... I guess the 2 derasas I had were big enough to not have the byssal threads anymore so I wrongfully equated that back throughout their life.

 

[SMSREEF]

Nitrate is at 2ppm. I tested last night.

That should be enough.