Clam FAQ!!

[Wiskey]

Clam FAQ

In a few words this is meant to be a beginner’s guide to Clams, it is a few short answers dealing with the Tridanca Clams commonly kept in Salt Water Reef tanks. The specific species discussed will be T. Derasa, T. Gigas, T. Squamosa, T. Maxima, and T. Crocea, as they are the most commonly available, and commonly kept.

These are all photosynthetic clams which both filter feed and depend on powerful lighting which they pick up with their mantle to provide nourishment and energy for health and growth.

The particular questions that will be addressed are as follows:
1. Is your tank ready for a clam?
2. ID of your clam, telling the most common species from one another.
3. Lighting for your clam, what does yours require to be happy?
4. Placement of your clam, does it like rocks or sand?
5. Basic ways to tell if your clam is happy specifically, gaping, and mantle extension.
6. Maintaining CA and ALK for your clam, they use more than you think!
7. Should I buy THIS clam? (Special considerations for smaller clams)
8. Transporting and “burping” your clam, the things you need to know to get it home.
9. Pyramidellidae snails.

1. Is your tank ready for a clam?

It is hard to sum up what makes a tank “ready” for a clam, but there are a few rules of thumb that I have found do it rather well.
--First off tank maturity must be addressed, I would say the tank must be a minimum of 6 months old, this means that the last piece of LR you put in the tank, the last time you added sand or live sand, etc,.. was 6 months ago. This time gives the final stages of die-off in the rock time to cycle through, some time for benifital life forms to colonize and make a comfortable home, time for you to get a grip on the essentials of running your tank. By this time you should be comfortable with all the equipment, have a good handle on the proper way to do water changes and matinence, and the aquarist has come down to a routine of matinence, so major changes in husbandry no longer happen.
--Second is Coralline algae, Coralline algae is a great tool to use when looking at a tanks stability, it is a rather finicky algae that grows well in the proper conditions for calcifying animals, and does not take to major changes well. If you have a good amount of growing coralline algae in your tank, chances are that a clam will also do great.
--Third is testing, I recommend that major prams (CA, ALK, Nitrate, Phosphate, PH, Salinity, and Mag) be tested once per week (or more), if you tank is ready for a clam you should get the same results from your tests every time you run them. The aquarist should be comfortable enough with the tank, and experienced enough with the way it runs to be able to predict the result of every test and be right. This does not mean you can stop testing, but it does indicate stability of your tank, this is going to make your future clam’s life easer and he will thank you for it with good growth and great color.

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[Wiskey]

2. ID of your clam, what is it? Clams have distinguishing charistericts that can help us tell one species from another. What some of those differences are I will go over here.

-Derasa,.. This clam has a thick and heavy shell when compared to others; its shell is normally vertically smooth without scoots (protrusions from the side of the shell). When you look horizontally along the shell it is wavy (goes up and down smoothly). This clam has a solid arc line long the side of the mantle, it is not “peddled” like Maxima tend to be, and the inhalant siphon has clearly visible tentacles. Interestingly enough it looses its byssal gland as it grows, and depends on its own weight to hold it down. Max size reported to be about 20 inches.
-Gigas,... These have many of the same charisterics as the Derasa clams, thick heavy shell, lack of scoots, solid arc line on the mantel and wavy horizontal look of the shell, and they also drop their byssal gland as they grow. Some of the differences include, Gigas don’t seem to extend their mantle past their shell as far as Derasa. The inhalant siphon has no tentacles and they can grow to be much larger at a maximum of 4 feet long! Not for nano tanks
-Squamosa,.. The shell of these clams have widely spaced scoots, along with a symmetrical shape. The mantle has a more pedaled look where it comes over the shell, and it extends a long way past the shell’s edge. The inhalant siphon has many large branched tentacles. This clam is often confused with the Maxima due to the scoots, but the scoots are far larger on the Squamosa, and not as close together. Max size 16 inches, usually found in the wild attached by their byssal threads, on the sand.
-Crocea,.. These clam’s shell is symmetrical, and has closely spaced scoots, it may have no scoots from the bottom of the shell if it is harvested from the wild because these clams sometimes boar into the rock grinding down their bottom scoots. They have a large and wide byassis gland opening, and the inhalant siphon has very small, fine tentacles. The max size is between 6 and 9 inches.
-Maxima,.. These clams don’t have a symmetrical shell; it is usually asymmetrical and elongated. They are 3 times as long as they are wide, have a short hinge, and a large byssus gland opening. The incurrent siphon has small fine tentacles, and it has scoots that are low and close together. Maximum size is about 14 inches, it is one of the smallest “giant” clams.

3. Lighting considerations for clams.
-This is a hard topic to discuss properly without everyone having a way to quantify lighting such as a submersible PAR meter so I will have to fall back on the old standards.
- Crocea and Maxima are the highest light demanding of all the clams, they require very high intensity light, a correctly setup MH or T5 HO with the good reflectors and allot of bulbs, basically if you can’t keep the most light demanding SPS corals, you can’t keep these clams.
- The other types of clams, Squamosa, Derasa, and Gigas can get by with lower levels of light, very intense PC light that is properly setup will get them by, but they would prefer more light than that. I think the rule of thumb here is if you can keep monitpora species (a less light SPS coral) then you can probably get by with one of these clams.

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[Wiskey]

4. Placement!

-Squamosa, Derasa and Gigas prefer being in the sand, however I have been successful with keeping all but Squamosa (never tried) on the glass bottom of my tank and they were plenty happy. [edit: VWD reports sucess in keeping a Squamosa Clam on the bottom of his BB tank.] This says to me that they don’t “need” sand placement so if you have less light you may want to put them higher in your tank to keep them happy. Maxima and Crocea should always be on the rockwork, they are rock boring clams and are usually not happy on the substrate. This also helps because they are such high light clams so you can place them right under the light. A tip, you may want to attach these clams to a small rock that can be placed in your rockwork because if you ever need to move him it may not be possible to get them off the rock.
-Flow, this is part of placement so I put it here. Clams don’t mind allot of water moving in the tank, but they don’t like much direct flow on them. The rule I have always used is that if it moves the mantle around, it is too much. Maxima and Crocea clams can take a little more flow than the other types, but they still don’t like to be beat up by it.

5. Health, basic ways to tell if your clam is happy.
-This is a largely visual thing so I recommend you look up as many pictures of your clam as possible and compare how yours looks to the pictures. Two major things to look for are mantle extension and gaping.
-Gaping is when the “mouth” of the clam is a large opening, this mouth should be more of a slit than a large hole, if it is a large hole then it is a sign of stress. The clam may gape from time to time for a short period of time, but if it does it regularly you need to find out why.
-Mantle extension, the clam’s mantle is the way it retrieves light and nourishes itself, but if the clam is not healthy or being picked on it will not extend its mantle all the way and eventually die from lack of light. If the clam is closed or only partly open during the day you also need to find out why.
-bleached or white areas in a clam’s mantle are also something that should grab your attention, this is also a sign of distress and left unchecked could cause a serious problem.

6. Maintaining CA and ALK, they use more than you think!
-There are numerous ways to maintain you CA and ALK levels and I won’t go into those here because they are somewhat out of the scope of this article; however it should be noted that clams use these elements at an amazing rate. I recommend that you pick up a Salifert CA and ALK test and run your tests regularly (2 or more times per week) in the first month or so your have your clam. I recommend levels of CA and ALK at 425 PPM CA, and 9.0 DKH ALK, but provided the levels are in balance you could run a range of different values. ALK between 8 and 11 is appropriate, and CA between 420 and 450 would be fine, just keep it stable, and if you chose to run an ALK of 10 DKH, find out what balanced CA is and keep the CA there.

7. Should I buy THIS clam? (Special considerations for smaller clams)
-If you have never had a clam before, I simply wouldn’t buy one less than 3 inches.

They have a lower chance of survival because they need to be fed. There mantle is not yet big enough to collect the light they need so without removing the clam and putting it in a bowl full of phyto every day. I think this is too much work, so I just make sure that the clams I buy are over 3 inches.
I no longer beleive this to be true, I do not beleive smaller clams need to be fed,.. Please see this post for a discription as to why: http://thereeftank.com/forums/showpo...4&postcount=12

It is true that larger clams are more hardy though,.. and I highly reccomend that people buying their first clam stick to larger ones as there less touchy.

-When looking into buying a clam there are a few things you should look at. You need to make sure the byssusal gland (some call it a foot) is not torn, because this could lead to early death.
-Briefly pass your hand between the clam and the light, this should make the clam immediately “flinch” if it does not the clam is not healthy, or at least not happy I would not buy it.
-The clam should not have bleached areas in its mantle, it should not be gaping, and it should have good mantle extension.

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[Wiskey]

8. Transport and “burping” of your clam.
-Clams are unlike other corals in this aspect, the problem is that if you take a clam out of the water it will squirt you in the eye because it doesn’t like being out of the water. Trust me, it will! The other problem is that after it squirts you it will pull in a whole bunch of air, if you place the clam in your tank after this it will have a bunch of bubbles stuck in it. There are 2 ways to get around this and I will discuss them both.
-First, it is important to drip acclimate your clam to get it used to the water in your tank, do this for at least 1 hour, I do it for 2 to be sure the clam is not hurt.
-I am paranoid about getting LFS water in my tank so this is the way I do it. I have the LFS not take the clam out of the water while bagging it, and make sure the bag is sitting so that the clam never hits air as I am driving home. Once I get home I drip acclimate for 2 hours, once again making sure the clam never hits air. I then remove the clam from the water, get squirted in the eye, dip place the clam in a small picture full of my tank water, let it open and close a couple of times, pull it out of the container, get squirted in the other eye, and place the clam in my tank. When I put the clam in my tank I put it in leaning up on a rock at a 45 deg angle with the “mouth” straight up, I always do this with the tank lights on. I leave the clam like this for an hour or so, and he will open and close, during this time he will expel all the air from himself and I can then place the clam in its final location. This is called “burping”.
-The other way is simpler, never let the clam hit the air, and you will never need to burp it, but the problem is that you can’t do this without getting some LFS water in your tank, so I don’t do this.

9. Pyramidellidae snails: I didn’t go into much detail on clam disease in this article, but these snails are one thing that bear mentioning, you should check for them before buying any clam. There is a great reference at the bottom of this article that talks more about the various diseases that clams get, and it is definitely worth reading. These snails are very small, they measure from 2-4 MM long, they stay out of the light during your photoperiod hiding in scoots if available, or down by the base. At night however they come out, walk to the top of the clam and poke a small needle into the clam’s mantle to extract and feed on the juice inside. These things are nasty, a single snail is capable of laying 2-3 egg masses per day, each containing 120 eggs. The best way to look for these are to see the clam at night, though this is not always possible, other things to do is to look very carefully between the scoots and at the base of the clam. A quarantine period is always recommended so if you get a clam with a problem your whole tank does not become infected.

I hope this helps some people enter into the wonderful world of clam ownership, if you have any further questions feel free to start a thread in this forum and ask away, we are here to help! Good luck and happy reefing!

References:
A great amount of my information came from this website, it is a great reference on clams and I recommend giving it a read:
http://animal-world.com/encyclo/reef/clams/tridacna.htm

This is definitely worth a read, it is the part of the reference section of this website that deals with clams:
http://thereeftank.com/forums/http://www.thereeftank.com/forums/f109/

This is another good sight with some information on clams:
http://www.reefs.org/library/talklog/r_gent_020898.html

This is a great reference on clam disease:
http://animal-world.com/encyclo/fishnchips/sept99/fnc0999.html

This is a good article on Clam ID:
http://www.reefkeeping.com/issues/2002-07/jf/feature/index.php

Great general clam link
http://www.wetwebmedia.com/ca/cav1i3/Clam_care/Clam_care.htm

I hope this article was of some help!
Whiskey

[Wiskey]

Clam pictures below are sorted by Clam type, one type per post. These Pictures are from your Fellow TRT members, they were kind enough to submit them for my article here. The person who submited the pic is listed under the pic, a big "Thank-you" to everyone who hooked me up with pics to use!


I am closing and sticking this thread, but if you have any questions or comments about this article please post them here, that way future readers will have access to further info on Clams:
http://thereeftank.com/forums/showthread.php?p=833921#post833921

Thanks,
Whiskey

[Wiskey]

Thanks Viv!


Thanks Reefneck!


Thanks Wharyat!


Thanks ThePlatipus!


Thanks again Reefneck!


And Thanks again Wharyat!

Whiskey

[Wiskey]

Thanks Reefman23!


Thanks ReefStock!


Thanks Charlie!


Thanks Reefneck! (Man, you are big into clams )


Thanks ReefNeck!


Thanks Wharyat!


Thanks Mg!

Oops got to break this one, Page one done,
Whiskey

[Wiskey]

Thanks Wharyat! (you have quite a few clams too )


Thanks Wharyat!


Great Shell shot, Thanks Nyles!

Whiskey

[Wiskey]

Thanks Reefneck!


Thanks again Reefneck!


Thanks Charlie!


Thanks Mg!


Thanks Viv!

Whiskey

[Wiskey]

Thanks Charlie!


Thanks Mg!


Thanks LadyReefNeck!

Whiskey

[Wiskey]

I found a member with a Gigas! Nyles was kind enough to PM me a picture of his. I still need to post a picture of mine, and I need to add my Derassas and my Maxima to the pics too.


Thanks Nyles!

Whiskey

[Wiskey]

Phyto and Clams:

In the first post of this thread it was suggested that Phyto be fed to Maxima clams,.. But it is a long held hobby myth that any clam under 3" should be fed Phyto, by means of the boal feeding method, or by puting a container over the clam and injecting phyto into the container,.. or more simply feeding it directly to the tank.

There are certainly plenty of phyto supplements out there,.. and it is proven that clams do eat phyto, but do they need it?

Why do we care? Phyto is not something I want to add to my tank,.. it's loaded with phosphate (anyone looked up how they make this stuff? ) and with the exception of some feather dusters and sponges and such almost nothing eats it directly.

Also, phyto is naturally occurring in our tanks,... anyone that has skimmed wet has probably come up with a green skimate,.. that's phyto at least in part.

The following references are from a book called "Giant Clams in the Sea and the Aquarium" by James Fatherree,.. It's a really good book, and I recommend anyone that's into clams go pick it up. I used to reference a number of different sources for info,.. but now I'm happy to say I don't need to because it's all there.

The book goes into amazing detail at how these numbers were reached, and sites the studies they came from,.. but to avoid copywrite infringement I will just give a brief overview lol.

The first thing the author does is setup an Acronym called "CZARG" (page 45) This is the percentage of a clam's daily respiratory and growth/reproductive needs that are covered by the Zooxanthellae. A CZARG Value of 100% would mean that a clam could satisfy 100% of it's carbon/energy needs by zooxanthellae alone, and not need to filter feed at all to be healthy and grow at a normal rate.

Initially it was thought that the energy provided a clam by the zoox was much lower than it is in actuality so that's where these myths came from, the calculations used to find these first numbers are now considered to be way off.. For details on this I refer you to page 46 and 47.

The book references Klumpp & Lucas (1994) in finding CZARG values (page 48 for below)
2.2cm Derassa (less than 1 inch) =140%
2 cm (less than an inch) Tevoroas = 140%

Refrencing Klumpp & Griffiths (1994) CZARG values
4.2 Cm Gigas (1.68 inch) = 191%
2.4 cm Crocea (just under an inch) = 206%
4.2 cm Squamosa (1.68 inch) = 118%

Page 49
Fitt & Trench (1981) did a study on how Squamosa acquired it's zoox and reported that over a dozen clams were raised from sperm and egg in filtered sea water with no access to particulate foods at all and were maintained for the 10 month study. They didn't do any studies on CZARG, but reported that the clams didn't just live but grew.

Now remember that a CZARG value of 100% means that the clam meats 100% of it's needs for C/E for health and growth/reproduction off just it's zoox and light.

So,.. after reading this data I decided that before I update anything I should probably try this out for myself,... I went out and bought a Maxima clam that was just under an inch,.. but a beautiful blue,.. I'd have been bummed if I killed it. The tank I got it from had Monti eating nudies,.. which forced me to Q this clam for a month under very weak PC lights,.. big mistake. By the end of the month the clam was in seriously bad shape. I moved it into my 125 after the month and immediately left for a week long trip to San Diego (bigger mistake),.. The Clam was then shocked by the sudden increase in light and bleached on me, and to make matters worse got pinched mantle! I was forced to do a FWD on it when I got back from Cali, and I shaded the clam and it slowly started to regain it's color. I then acclimated it carefully to the MH and it really started to take off. It got better and started growing quickly,.. and that clam now 5 months later is almost 3 inches in size.

Do I recommend buying really small clams?

Well,.. They are far more touchy,.. and much more sensitive so I guess it depends on your confidence in your setup and experience with clams,.. but be aware the small ones go downhill much faster than the larger ones will.

I hope this helps despell a hobby myth!
Whiskey