Clam not opening all the way.

[NikkiPotnick]

Hello all,

I got a small Maxima clam from Pacific East Aquaculture a few months ago, and it has been doing great until the last few days. It now only opens partially, and I've noticed that the mantle doesn't seem to extend as far on one side.

My water parameters have been stable, and I haven't seen anything nipping at it. I'm at a bit of a loss and starting to get worried.

My lighting is two Illumagic X4s. I don't have a PAR meter, but the clam is positioned almost directly under one of the lights.

Any advice would be greatly appreciated. I've attached a few photos.

 

[Mr. Mojo Rising]

I don't see new growth on the shell, so it has been starved for light for a while. Personally I would try to move it up closer to the light. The most important thing is to see a layer of bone white new growth at top of the shell, a clam is always growing until the day it starts dying. @minus9 is one of the clam guru's maybe he can offer more comment.

 

[kevgib67]

@OrionN ?

 

[EnterName]

As yours didn't close up very soon after being introduced, I don't think it was too much light, but this is another possibility (happened to me once). Some time ago I purchased a Tridacna from a large European coral shop. After it had closed up after a few days I asked them at what PAR level they keep their Tridacnas. They recommended 250 PAR, while I had accidentally grilled mine in 380 PAR and didn't know because the PAR meter was still being delivered. I'm sure it is possible for them to get used to higher levels, but the sudden increase was too much.

They additionally recommended feeding them with Nannochloropsis sp. phytoplankton and Nyos LYQ-RED.

 

[NikkiPotnick]

As yours didn't close up very soon after being introduced, I don't think it was too much light, but this is another possibility (happened to me once). Some time ago I purchased a Tridacna from a large European coral shop. After it had closed up after a few days I asked them at what PAR level they keep their Tridacnas. They recommended 250 PAR, while I had accidentally grilled mine in 380 PAR and didn't know because the PAR meter was still being delivered. I'm sure it is possible for them to get used to higher levels, but the sudden increase was too much.

They additionally recommended feeding them with Nannochloropsis sp. phytoplankton and Nyos LYQ-RED.

Interesting. One variable change I made recently was I ramped the lights up a bit. I will lower them again to what I had them set at before and see if that changes anything.

 

[BriDroid]

I agree that if you’ve had it for a few months, there should be white growth on the edges of the shell. Here is my little 2 inch maxima that I’ve had for about the same amount of time. You can see all the white new growth.

 

[NikkiPotnick]

Hmm I believe I do have growth though. You can see it a bit from this angle.

 

[BriDroid]

Is he firmly attached to the rock, or just kind of half attached? Mine had small growth lines like that early on when it wasn't fully committed to the spot I placed it. Once I moved it to around 250ish PAR, it fully attached and started growing.

Since it just started, make sure that there isn't anything along the edge of the shell irritating it. I had a few bubble algae bubbles on one of my little crocea clams and it would close up and make slime. It looked very similar to how yours is closed up. Once I plucked them off, it is happy again. I honestly think they are a lot tougher than most people make them out to be. You just need to figure out why it's not happy, then treat it like an acro, it will grow!

Here’s how mine looked when it wasn’t happy. Very small, if any white growth, similar to yours. I was determined that it had pinched mantle disease. It went through two fresh water dips and is growing like a champ today. Turns out it just wasn’t happy where I placed it. Like I said, I think they’re tougher than people act.

 

[NikkiPotnick]

Is he firmly attached to the rock, or just kind of half attached? Mine had small growth lines like that early on when it wasn't fully committed to the spot I placed it. Once I moved it to around 250ish PAR, it fully attached and started growing.

Since it just started, make sure that there isn't anything along the edge of the shell irritating it. I had a few bubble algae bubbles on one of my little crocea clams and it would close up and make slime. It looked very similar to how yours is closed up. Once I plucked them off, it is happy again. I honestly think they are a lot tougher than most people make them out to be. You just need to figure out why it's not happy, then treat it like an acro, it will grow!

Here’s how mine looked when it wasn’t happy. Very small, if any white growth, similar to yours. I was determined that it had pinched mantle disease. It went through two fresh water dips and is growing like a champ today. Turns out it just wasn’t happy where I placed it. Like I said, I think they’re tougher than people act.

I appreciate the reply. I moved the clam down a bit and on a rock that seems better for it, I noticed it was not attached. Right when I turned around to check the clam again I noticed my tail spot blenny nip at the clam shell! I wonder if my Benny is irritating it…

 

[BriDroid]

I appreciate the reply. I moved the clam down a bit and on a rock that seems better for it, I noticed it was not attached. Right when I turned around to check the clam again I noticed my tail spot blenny nip at the clam shell! I wonder if my Benny is irritating it…

That’s one of the reasons I didn’t add a tailspot to mine! You may have just solved your mystery!

 

[NikkiPotnick]

That’s one of the reasons I didn’t add a tailspot to mine! You may have just solved your mystery!

I had no idea tail spots nipped clams !

 

[BriDroid]

I had no idea tail spots nipped clams !

I didn’t either until I asked google if they’re reef safe

 

[minus9]

There's a little growth, but there could be more and there's no way you can over-light a maxima, especially one that's been in you tank for that long. As you figured out, your blenny is nipping at the mantle. Put the clam back up towards the top and turn your lights up. Re-home the blenny and enjoy the clam. As long as you have measurable nutrients, you have plenty of "food" for the clam, you can dose phyto to the whole tank, which is a great way to feed the food chain that benefits the whole tank. I would increase your lighting, as that clam should have a healthy growth margin like @BriDroid posted.
Clams don't need a lengthy acclimation to lighting, find a good spot for them and crank the photons! If you don't see new growth on a clam, then don't purchase that clam and when you purchase one online, ask for a side shot to see the growth. If they don't want to send you any pics, move on to another vendor. Also, maxima should be getting about 350 micro moles minimum for at least 8hrs a day (full spectrum lighting, not blues).