Clam Stress and Suggestion

BonsaiNut

Premium Member
I am posting this note only after keeping clams for years and reading some of the problems people are having. Note that my thoughts are based on personal experience only - I am not a marine biologist.

In reef tanks over the years I have kept large numbers of tridacna clams. Some of them were purchased, while some of them were collected in the wild (by myself). In general, my success rate was very high and I found these inverts very forgiving once they were established in a reef tank and recovered from shipping stress and/or collection damage. However, when clams start to go 'bad' they can succumb very quickly if the signs are not recognized and appropriate action taken.

Smaller clams in the wild (less than 1') are ALWAYS firmly anchored to the substrate. In most cases, the clams (through vigorous rocking action) can slowly grind away the coral rock beneath them, causing a substantial concave depression that protects much of the clam (and most importantly protects the 'back' of the clam from predators). In some cases, the clam can be over 75% buried in rock, so that the clam shell can only open partially, and when the clam's mantle is withdrawn very little of the clam is visible. In the wild clams are more firmly anchored to the rock (when young) than you would believe - it is easier to remove the clam with the surrounding rock than to try to separate the two. Healthy clams react VERY strongly to stimuli, contracting their mantles into their shells, closing their shells tightly, and anchoring themselves more firmly to the substrate.

The most noticeable way to detect that your clam is in trouble is when it starts to exhibit a 'gaping mouth' look. This is when the clam seems to be gaping open - its two shell halves are open wider than normal and the clam tissues almost appears stretched between the two shell halves. Note that the largest and strongest muscle in a clam is its 'abductor' muscle - which is the muscle that closes the two halves of its shell. A clam's shell is like a spring - if the clam cannot hold the two sides closed, it will automatically open up, even at a time when the clam most needs it to be closed (to recover from damage, stress, etc). I have had clams that demonstrate this 'gaping mouth' look even in tanks that have held other clams that were so healthy as to be spawning and otherwise behaving vigorously.

I have found that once a clam starts to exhibit this 'gaping mouth' look the mortality rate was almost 100% if action was not taken quickly. However, I was able to significantly reduce the rate of mortality to 10-20% by taking a very simple step. I would tie the clam closed.

The idea of tying a clam closed came from the simple intuition that clams close when they are in a risk situation, and that when clams exhibit 'gaping mouth' they are open beyond their normal healthy range. Perhaps (though I don't know) their abductor muscle is damaged, or stress has weakened them to the point where they cannot contract the muscle, so that the natural spring-like mechanism of the shell is slowly tearing the clam in half. Regardless, I use binder's twine or some other reef-safe material to tie the clam closed almost 100%, leaving just a 1/8" opening. In the vast majority of cases, this simple treatment will have a dramatic impact on the clam.

Normally as a clam recovers from its stressed condition, they will slowly project more and more of their mantle through the crack each day. A clam can project almost 100% of their mantle through a 1/8" crack (if the clam is hobby size - 6" or less). Wait until the mantle is fully extended during the day, and then remove the string, or (in cases of severe stress or damage, loosen the strong for a week or two before removing it entirely). Usually clams would recover strength in about two weeks.

I hope this note helps people with their clams, and may save a clam or two. Note that this treatment assumes an otherwise healthy environment (good water conditions and absence of predators). Clams for me were especially susceptible to bristle worms through their byssal opening (at the back of the clam). If your clam releases a brown mucus at the back of the shell, wait until nightfall and check to see what is irritating the clam - in most cases worms are getting behind the clam (something which does not happen in the wild due to the depressions in the rock where the clams live and their ability to rock/grind against the substrate). Note that I have NEVER seen a wild clam in sand. In all cases they were anchored on solid rock. On reefs in the wild you could see where larger clams were harvested by natives for food - the clam depressions were clearly visible.
 
Well written and well done! I will try this and let you know. I house about 100 to over 200 clams at any one time and you are right on the money with everything stated. I would like to hear more!
Where abouts in Orange County? I lived in Tustin for about 8 years.
Jim
P.S.
May I reprint this in my website? www.tanku.net
It is all clams.
 
Have to agree with Jim, Very well written.

I have heard of this method before from a Marine Biologist in Florida but have never tried it.

Barry
 
Hi Guys -

Feel free to copy this information anywhere that it might do some good. I was in a store the other day and I saw a stressed clam and I thought to myself - that clam is gonna be dead within 24 hours - but I could probably save it. It made me feel bad, especially when this simple treatment worked amazingly well for me. In the past, I have taken clams that looked REALLY bad and tied them almost completely shut and they have come back. On occasion, with really bad cases, the clam was tied shut for so long that much of algae in the inner tissues of the clam had died off. However, as long as the mantle was healthy, and the clam was gradually reintroduced to full light (by loosening the string gradually over a week or two), the clam colored back up perfectly. As far as I am aware, I have never killed a clam by tying it shut too tightly - clams I have seen in the wild have sometimes bored into stone to such an extent that they can only open 1/8" or so at most, so they don't seem to be adversely affected by the treatment.

Let me know how everything turns out. I expect that you are going to be very happy with the results, expecially if you keep so many clams.

I live in Laguna Hills :) I actually lived in Tustin myself for about three months when I first came out to Orange County. I LOVE the location and the weather - but the electricity is killing me :) I left my reef tanks back in Chicago (because of an agreement my wife and I had while we were having children), and have been keeping myself satisfied with a 7000 gallon koi pond - but after keeping a reef there really isn't much challenge with it (though it is kinda fun to be able to swim in your 'tank' while doing maintenance). Of course now I am thinking about starting up a new reef tank and every time I think about the $100/month just for the metal halide lighting I wince.

I plan on going out to Polynesia in about five months - maybe I could take some photos of clams in the wild so people could see what they look like and where they live?

- Greg Peterson
 
I recently moved the contents of a 28 and 34g (old tanks) into a new 150g and added even MORE (75lbs) cycled live rock so I pretty much never cycled.

I'm about 2 months into the new tank and I had to take my blue spot puffer (he was a new addition from a local friend) because it was nipping at the clam.

Almost immediately, the clam began to open again as it did in the old tank once the puffer was gone however, I noticed today that the mouth is wide and there is a 2nd hole from what appears to be damaged or missing tissue below the mouth.

He's open and reacts to stimuli but I wanted to run these images by you if you wouldn't mind giving me your opinion. I don't want to assume he'll recover and find him dead!

IMG 1: https://www.dropbox.com/s/s1i4jp1d0rs1bhk/2016-09-21 10.15.51.jpg?dl=0

IMG 2:
https://www.dropbox.com/s/ds72ukpo2l4cgvx/2016-09-21 10.16.14.jpg?dl=0

IMG 3:
https://www.dropbox.com/s/ph3ys8uyk9eg9jt/2016-09-21 10.16.23.jpg?dl=0

Thank you!
 
I recently moved the contents of a 28 and 34g (old tanks) into a new 150g and added even MORE (75lbs) cycled live rock so I pretty much never cycled.

I'm about 2 months into the new tank and I had to take my blue spot puffer (he was a new addition from a local friend) because it was nipping at the clam.

Almost immediately, the clam began to open again as it did in the old tank once the puffer was gone however, I noticed today that the mouth is wide and there is a 2nd hole from what appears to be damaged or missing tissue below the mouth.

He's open and reacts to stimuli but I wanted to run these images by you if you wouldn't mind giving me your opinion. I don't want to assume he'll recover and find him dead!

IMG 1: https://www.dropbox.com/s/s1i4jp1d0rs1bhk/2016-09-21 10.15.51.jpg?dl=0

IMG 2:
https://www.dropbox.com/s/ds72ukpo2l4cgvx/2016-09-21 10.16.14.jpg?dl=0

IMG 3:
https://www.dropbox.com/s/ph3ys8uyk9eg9jt/2016-09-21 10.16.23.jpg?dl=0

Thank you!

Not sure if you realize but this thread is 14 years old!! Maybe someone will chime in but not sure if any of these guys are even on this form anymore. I would help but im new to saltwater so im a newbie sorry..
 
Almost immediately, the clam began to open again as it did in the old tank once the puffer was gone however, I noticed today that the mouth is wide and there is a 2nd hole from what appears to be damaged or missing tissue below the mouth.

I'm not sure which "hole" you are referring, to because I can't see one in the photos. You realize that giant clams have two holes in their mantles, naturally - one is the inlet siphon and the other is the exhalent siphon. Just like it sounds, water goes in the one end and out the other :)
 
I saw this thread and I'm giving it a try.... My local reef store is owned by a friend of mine. He's having a system crash of some type and asked me to see if I could rescue a t-max clam. I bought the one on the right from him about a month ago, and the one in the upper left is the rescue. The clam was gaping pretty bad. I put a ziptie around him and gave him slightly more than a 1/4" opening. Hopefully this will do the trick. I'll report back if it was successful.

 
Sad to report the clam died this morning. Unfortunately we caught it too late, and this isn't an indictment on the method. I just didn't get the call to rescue it in time.
 
Maxima has been gaping again so I've placed it on rock (before it was only in the sand) and I closed it with a rubber band. I hope this does some good. Any feedback?

I noticed it was gaping after directly feeding it reef roids and phytochrom the other night.

https://vimeo.com/195210602
ac78042a24498c42366be633e5694ffa.jpg



Sent from my iPhone using Tapatalk
 
do NOT force your clams closed. this is just bad one very level.

clams need to be open to photosynthesize, exchange nutrients in the water, and for respiration purposes.

UNTIE HIM NOW!

i don't know where, how, or why this myth about forcing clams closed but started but it is absolutely without merit, it even goes against their basic physiology.

http://www.reefcentral.com/forums/showthread.php?p=24313359#post24313359

i doubt that will do anything to help a clam recover.

the opening of the shell is provided by the tension of a ligament. as noted in that post. when the clam is at rest, it is open. tying it closed would only serve to restrict mantel extension and limit it's ability to photosynthesize.

a month isn't a long time for a clam. it could have been having issues long before it came to you, and just now started to succumb to them. in my experience Tridacna clams (especially T. derasa) look fine right up until they're not, and telling a healthy specimen from a doomed specimen takes some experience, and a little bit of luck.

the first thing i always asses with a new clam is the growth edge on the shell. that's a good lagging indicator for long term health.

here is a picture of mine early morning, so his mantle was out of the way. you can see near the top of the shell the clean, white edge, indicating recent calcium precipitation on the shell"

21yFB4r9RuGsmh1Gy4VRbpITa0J0VK1PNgezlK1zeQIqifJ3G4ZgQ8RPYlCo9lQlMv0YlYtidt8-ei0rw8kYbrC9Pd06aaVAEgoAG_3OSKaS94EkXHWsxtiUJZjDnvyBOuiXycrUoOeKYyGIA5qBQBPQpBfFG9ufuvFeDFBDKMfrxZrI226UDi14Kv4TpRg6JhUgcMxZNyddyI6rag7wZ_W2yRJyALffGJN5GkgH9bbM3LrmS9ooUEeH6o7xm2deZ49VvL-dGgOeSxr9jxCb6izRzk_FiKgq9Ms22DOrRtnNGyCXdncWiqqhDWGyyCha2ZIFnfn8sAd3NihdUNsmB3v6oS9Hp4UrYzSe6hRLnrvHwnuLDX2kmypjtJrBbkes1mTg44EhJ_PFKNuItzmwMoM9IxiZ21D6Zv4PxeGQ_qMbE3g7lFIf9vVrun-ZnaUtp5QZ3feEfuIsV7E0LKF__LQAW8IYYmz3F5pIjOc-ExsxSoVFZVpc2qmhHSHZdY7tZWHwOfbi3-_RsIuzyom5ltl1TXoXMyW3fPQJmRikzWe69eBc5j_8ii5MzhRTc1g=w737-h755-no


next is the reaction to stimuli, mainly shading. to be clear, a clam can have good reaction to shading, but still be in trouble. when the clam's reaction is weak or not present, that's usually an indicator of imminent demise.

after that i like to just generally look at it. the mantle should have a vibrant hue, and it should just look right for the species (not a good description, i know, but it's the best way i can describe it). the siphon shouldn't be gaping, on T. derasa it should be a fairly closed intake siphon.

is this the first clam you've tried to keep?

is it possible that you have something in your tank picking on it?

were there any signs of physical damage to the mantle or foot? any snails present?
 
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I removed the rubber band first thing this morning. It's doing well. I added a rock as I mentioned and it's already begun to attach to it. Gaping is gone today and it responds strongly to shading. **For the record I didn't force it closed yesterday. It closed and retracted when I picked it up.

Maybe I jumped the gun but after reading countless posts and information (including this forum) online I became convinced it was stressed and that tying it closed would benefit it.

At the moment I have no cause for concern as far as I can tell. Good response, attached to rock, vivid blue color.

This is my first clam, and all the more reason I'm trying to be proactive. I'd actually like to add one or two more in time.

Thanks for the tips. I posted on Facebook yesterday and I got replies from the Saltwater group from "He's a goner" to "They always look like that. It's perfectly normal". :hmm5:

This hobby.... LOL:crazy1:
 
do NOT force your clams closed. this is just bad one very level.

clams need to be open to photosynthesize, exchange nutrients in the water, and for respiration purposes.

UNTIE HIM NOW!

i don't know where, how, or why this myth about forcing clams closed but started but it is absolutely without merit, it even goes against their basic physiology.

http://www.reefcentral.com/forums/showthread.php?p=24313359#post24313359


[Citation Needed] Seems like you're citing opinion / anecdotal evidence as fact. Based on your join date, I'm more inclined to agree with the more experienced reefers until you can cite a primary source.
 
[Citation Needed] Seems like you're citing opinion / anecdotal evidence as fact. Based on your join date, I'm more inclined to agree with the more experienced reefers until you can cite a primary source.

you would be a lot better off if you judged my posts on the content than the join date, but that's your prerogative.

there's several papers out there that lay out how the muscle/ligament system in the giant clam functions. it is clearly stated that clams are at rest open, and require muscle contraction to close. additionally while closed clams are unable to take in light and water properly.

i also haven't seen a single instance of clam bondage that led to the clam recovering. so it seems like that might be the claim you would want to investigate.

i was in this hobby before i registered for this board, but hey, all my clams are alive and well, so feel free to quibble about join dates all you like. :love2:
 
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