Information

How to Keep and Care for Freshwater Clams in Aquariums


Jocelyn loves learning about different marine creatures. She has a Youtube channel where she creates instructional tropical fish videos.

Clams (bivalves) are wonderful additions to the aquarium. Undue to popular belief, they are not difficult to keep successfully in a properly maintained and aged home aquarium.

What Do Clams Eat?

Clams are filter feeders meaning they acquire life-sustaining nutrients by filtering the water around them. In most home aquariums, there are not enough proper suspended particles throughout the water in order to sustain the bivalve’s life. In cases such as these, the clams require supplemental feeding or they will starve.

Clams can survive for quite a while without food—it is an unfortunate fact that this aspect of their anatomy leads to their ultimate demise in the hands of inexperienced keepers. Their clams live for at times several months until the day they are ultimately found dead. A dead clam is no laughing matter.

Keep Your Clams Alive

When a clam perishes in an aquarium it will lead to a deadly ammonia spike that can quickly kill the other inhabitants of the tank. That is one downside of keeping clams and mussels in the home aquarium; they bury themselves in the substrate and are difficult to locate when dead. In a heavily planted tank, this can mean days of hard work tearing out and replanting uprooted plants. However, there is a way around this.

To keep clams contained in the aquarium place them in a single serve applesauce container. Poke holes throughout the container to aid in water flow through the sand. Fill the containers with a fine substrate such as sand. Three or four small clams can be housed per container. Larger clams may need a container to themselves; it depends entirely on their size.

When doing tank maintenance it is advisable to remove the containers and dig the clams out. Dispose of any that are dead. Dead clams smell like rotting, fishy flesh. Clams that refuse to close their shells are dead, dying or injured. They should be watched carefully preferably in a quarantine tank until observed acting normally.

How Do You Know if a Clam is Healthy?

Normal clams are quick to action. When the water is disturbed around and over them, they will close their shells. This is a natural defense mechanism and a good indication of health.

A well-fed clam will show visible growth over time. Measure each clam before adding to the aquarium. Once or twice a month remove them from their enclosures and measure again. If growth is happening and continues, the clams are feeding properly. No visible growth may mean they are starving. In the case of clams that are at their full size, time will tell if they are feeding. It is a good idea to have differing ages as the growth of the juveniles can be used to judge the whether or not the adults are feeding.

A Clam Is Not a True Filter

Freshwater clams do not clean their environment as many people claim. Though they are filter feeders these creatures act more like animals rather than plants. They do not remove nitrate and ammonia. They add these chemicals to their enclosures. They are animals—not plants.

Clams are sensitive to their environment and ammonia can be particularly deadly.

What clams do remove quite efficiently are various forms of suspended algae. A grouping of a few small heavily feeding clams can clear the water in a 5-gallon aquarium within hours. They also filter out tiny creatures from the water. In a sense, they are filterers, just not the kind many pet stores market them as; clams are filter feeders, not filters. You do have to keep up with tank maintenance when housing clams.

Questions & Answers

Question: Do clams open by themselves?

Answer: Yes.

Question: Do dead clams smell rotten?

Answer: Yes.

Question: My turtle got his toe stuck in my freshwater clam, how do I get it unstuck without hurting the clam?!

Answer: It should let the turtle go on its own.

Question: Can a freshwater clam live with a goldfish?

Answer: Yes, as long as your aquarium has fantastic filtration.

© 2010 Isadora

Brooke on July 05, 2020:

What do fresh water clams eat

Not you problem on April 06, 2020:

Do you need to have fish

and the fish to make the tank dirty and the clams eat it?

Barber on April 17, 2019:

Can I use dirt as sand for my clam

Me on April 24, 2018:

Just got two clams one died you were really helpful

Shelby on January 15, 2018:

I have clams and they’ve got this like white stuff coming off of their shells there cleaning my tank pretty nicely the algae starting to dissipate and I do you feed them more algae with a dropper so I can like feed by squirting some in instead of just pouring a lot of algae In but what is the stuff comming off there shells I also have calcium rock soaking in the container I put the food in so I can have calcium for them too what’s going on with them

Chris R. on August 04, 2017:

One of my clams is fully open and ive had him only for a couple days. What does that mean?

Joshua on July 05, 2017:

How much copper in the water can kill a clam?

julia on June 02, 2017:

what happens when you find a lake water clam or mussle

shawna on December 08, 2016:

I have had a clam for about a year now...I put her where the water current flows at her and feed her algae wafers . I position it about 2 inches from her mouth and while the shrimp eat at it the water current carries pieces of it to her. ..she opens real wide when i do this, about every 3 days . also I don't allow my water to be "sparkley" clean, it isn't filthy but if a very small amount of particles are swirling around , it will also provide food for her.I have also learned that if I place a piece of moss over the back half of her shell and being placed where the water current flows at her, she doesn't move around ...which also tells me she is eating well and content in the tank.

Jo on November 27, 2016:

How long should it take for new clams to start filtering? I received an order of 15 small clams two days ago. They are divided into 3 tanks. They are all alive, but only about 4-5 have buried themselves. I have also not seen any visible change in clarity of the water. Does it take them a while to acclimate and get going?

Also - what do you find to be the best temperature?b I have read some things that suggest a cooler temperature is better. Thanks!

David Grover on October 31, 2016:

What is the best type of water for keeping clams? I have a 3ft by 1.5ft by 1ft tank with 3 large goodies and 6 white clouds with a decent filter and kept at 22 degrees Celsius.

chriss on May 21, 2016:

kinda looking around the web for info like, preferred ph, substrate type ( I keep aragonite in my tank and suspect that it may be a bit sharp for their lil foot) preferred temp , water hardness so on... any help would be appriciated

Marco on March 10, 2016:

Hey I just found two live clams in my Creek and iam trying to take care of them but I'm not sure if my tank is the best thing for them cause my tank has gravel instead of sand . is that okay ? And was wondering if my plecostamus may eat them ? And i was wondering if it is legal even to take these clams from the creek ? I would appreciate your response and wanna thank you for all the info I've learned on here!

toya on January 02, 2015:

Hey ! Its me again so you just buy the ingredients and mix it & drop it in the fish tank ?? So to lay them on substance side , that's the side with the 2 holes on it ??

toya harris on January 02, 2015:

Hello ! so your clams recipe is real meat ??

Vivian on October 24, 2012:

I added 2 clams about 2 weeks ago. My tank was cycling because I had just done a big water change and also added new fish. After adding them one dug himself in just at the surface and I think they were moving...very slightly, but yesterday morning saw one was on top of gravel wide open. I waited till this evening and took it out when I saw it was the same. Did I kill it?

Isadora (author) from Tennessee on June 18, 2012:

Yes, they can kill your clams. They are pretty nasty fish in the tank mate personality department.

I keep my tanks no less than three inches deep with substrate. You can move the clams without harming them, yes. They will just move around on their own though.

Megan on June 18, 2012:

Also, I have sand in my tank about 2 inches, but the bigger calm doesn't fit completely under the sand, only about half way. Is this a problem? Does he need more sand? And if so can I just pick him up and move him and add more sand and put him back

Megan on June 18, 2012:

I just bought 2 calms, the small one buried himself immediately and the large one about 48 hours after being put in the tank. The small one resurfaced a few days later. My 2in convict has been picking at him since, can he kill the calm? What are some good and bad tank mates for clams?

hi friend from India on April 18, 2012:

more informative

kiwwi on April 07, 2012:

Thanks

Isadora (author) from Tennessee on April 07, 2012:

I have a natural aquarium so do not use carbon to filter it. You probably can use it though.

Provide enough fine substrate that they can fully bury themselves--this depends on the clams size. My substrate is anywhere from three to nearly six inches deep. Its sand and silt substrate.

No, they do not harm your plants. They will help to keep the substrate aerated/turned though! I love clams and miss mine dearly, lol. Hubby accidentally killed mine. Sigh.

kiwwi on April 05, 2012:

how much substrate do you need to keep calms and will they destroy plants? Also should I use a carbon filter with the clams?

Isadora (author) from Tennessee on March 20, 2012:

Here is a link to that food recipe.

Isadora (author) from Tennessee on March 20, 2012:

If their shells are tightly closed, they are probably okay. You can just keep checking them everyday, a couple of times a day to make sure they aren't dead. That or take them out. If you have a small air pump, you can keep them in a large bowl of tank water.

They need more than a few bits of leftover food to survive. I wrote a hub on food you can make for the clams. Good luck!

HeidiJoMar on March 20, 2012:

I have 3 freshwater clams. They are half white and they have brown on them as well. The brown is peeling off allthough. I have had them for about 5 days know and they have not moved at all. I was told that they are bottom feeders and the eat left over food. I have some nvery cool fish in my tank and i love them all. I am afraid they are dead. I ac not smell them due to bad cold. What do i do? I have expensive fish in my tank that i donot want to get sick. They include prehistoric goby, african butterfly fish, elephant nose, fire eel, black ghost knife fish, clown knifefish, 2 african clawed frogs and a few more. Very unsure what to do at this point. An suggestions?

Isadora (author) from Tennessee on March 12, 2012:

If it is still cloudy, you can do a partial water change. Make sure the water you replace it with is dechlorinated.

When you feed them, make sure you slowly aim the food towards their feeding tube. Use water the same temperature as the aquarium water.

I use a syringe without a needle to slowly drop food over their feeding tubes. Try mixing the crushed food with tank water and making a slushy with it. They really like tiny foods so if the crushed flakes are too big they wont eat them.

I have another hub on here on the recipe I used to feed my clams. Its pricey when buying the ingredients but they last a long time.

Here is the link to the food recipe.

.

leelee on March 12, 2012:

how will i know if they dead.. just cos it would be very smeely?.. and wat shall i do about the cloudyness.. will that clear on its own ?.. x

leelee on March 12, 2012:

just grinded up fish flake.. i read up and it said that was ok for them .. is that right ?

Isadora (author) from Tennessee on March 11, 2012:

The cloudiness may be a bacterial bloom. It usually means something is off with your parameters. I'm not sure what to tell you other than keep your eye on them and yank them out if they die.

What are you feeding the clams?

leelee on March 11, 2012:

i got them Friday and sunday now and they still the same .. they are closed and have been sat on the sand in same place since then.. ive read that the tank ment to get really smelly if they dead but dont smell any different from how its always been.. have noticed that water has gone slightly cloudy too.. unless that's from the cucumber that i give my plecs.. x

Isadora (author) from Tennessee on March 11, 2012:

They could be dead. Are they open or just laying on the surface closed?

Sometimes they will come to the top of the sand for a bit--they don't usually stay above the soil long, unless they are sick/dead.

Pick them up and give them a whiff. If they smell rotten, chunk them.

Make sure you only use dechlorinated water in their aquariums. My husband added tap water to my tank and it killed ALL of my clams within hours. I was so upset.

leelee on March 10, 2012:

i just got 2 clams .. there are both just sat on the sand .. ive had them about 2 days .. havnt noticed a change in them .. they are both just sat on 1 side of there shell.. are they ment to do anythin .. do they open ?

John on February 09, 2012:

Haha, thanks for the advice!

Isadora (author) from Tennessee on February 06, 2012:

I really don't know, lol. I probably wouldn't eat them because clams filter the water to get food. Lord only knows what chemicals they might have eaten. :O

You could probably make fish food outta them though.

I'd leave them alone. Just makes your pond more biologically complete! :-)) I love those little guys!!!

John on February 06, 2012:

Thanks for your reply!

Yes these are amall clams. And just out of curiosity, are these clams edible? I could make a meal of clam spaghetti out of them!

Isadora (author) from Tennessee on February 05, 2012:

Getting your pond to a good nitrate level shouldn't harm your clams. If they all died at once, it may harm your water chemistry. If a few died at the same time, you have enough water to probably handle it.

I am assuming these are small clams.

I've had things die in my ponds and the fish did fine. They just pretty much ate the dead things.

John on February 05, 2012:

My above post got cut off when I accidentally hit Post Comment.

I guess this is how the normal Eco system works. The question is, if I brought down the nitrate to more acceptable levels, 20-30ppm, would it affect the clams? I have detritus in the substrate which I guess the clams can still feed on. Any comments appreciated!

Thumbs up for this site!

John on February 05, 2012:

I have a small outdoor pond 260gal with koi. I have hard water and zero ammonnia and nitrites, however I have high nitrates in the region of 70ppm which I attribute to my plants dying due to predators like birds and even snails! My tank used to have a lot of algae due to the high nitrates and while doing a cleaning on my substrate, I found clams in there. Initially it was only 2, then it grew to about 10 or so (not sure how many are hiding further in the substrate). I do not mind having these clams in the pond, however hearing that they contribute to ammonia spikes upon death makes me a bit worried even when i have a relatively large body of water. I recently saw a snail opened up halfway and a few snails and some kind of worm feeding on it. I guess this is how a normal eco

Isadora (author) from Tennessee on January 24, 2012:

You're welcome. Thank you! :-)

TheUsedCarGuy from Melbourne Australia on January 24, 2012:

Great tips! Thanks :)

Isadora (author) from Tennessee on January 08, 2012:

Your questions got cut off.

This should work for the Mississippi mussels, yes. :-)

Some clams are real travelers and might escape their cups. All of mine stayed put, as long as they were fed regularly. Hungry or stressed clams tend to move around as they try and find a better place to live.

They should make neat additions to a nature tank! Good luck. :-)

bugguy123 on January 08, 2012:

I would like to keep a variety of Mississippi River mussels for display at a nature center.

Do they actually stay in a container with holes put in the substrate?

Would your feeding recipe work for them? Do the

Isadora (author) from Tennessee on December 17, 2011:

I'll be honest with you ...I wouldn't put anything else in your tank.

I'm almost positive the convicts would harass your clams to death though.

craig on December 17, 2011:

I have 6 convicts and 4 brisstlenoses 2 rainbow sharks a golden shark a green terror a ghost knife and a yabbie. Can I put a mussel in with them in a 3 and a half foot tank?

Isadora (author) from Tennessee on November 06, 2011:

Thank you! :-)

Steve Andrews from Tenerife on November 06, 2011:

Voted up for this very interesting hub!

Isadora (author) from Tennessee on October 28, 2011:

That much bioload may kill your clams. You would have to have a kick-butt filtration system set up. You can do natural filtration or mechanical. The turtles may eat the clams though.

potatochobit on October 06, 2011:

I have a baby turtle tank

and the turtles are soo messy!

they tear the food pellets when they eat and it gets everywhere

the water clouds up instantly

I am wondering if a clam can help this?

Isadora (author) from Tennessee on September 21, 2011:

I would check them daily or at least every two days. Check your ammonia levels once a week too. If you look closely at the substrate, you should see the clams mouth opening. As long as that is moving(filtering)the clams are alive.

If they die, clams can kill your fish if you have them in a small tank. The bigger the tank, the better. That way the ammonia spike isn't so harsh. Make sure you feed the clams because they will starve to death if you do not.

Steve on September 21, 2011:

I just added two clams to my tank and it's not something I've ever looked up really and the pet shop couldn't tell me much either but I like things that are different.

One dug himself into the gravel within hours but the others still sitting on the top. How risky is it keeping them with how you said about the ammonia spike when they die? I've got a fair few fish and don't want to risk any.

Isadora (author) from Tennessee on September 15, 2011:

I would say it buried itself in the substrate FishLover. Look really closely at the substrate--you can usually see their little tubes sticking up, filtering the water. It would be like two small, pulsating holes in the sand.

Isadora (author) from Tennessee on September 15, 2011:

They might eat them, Chris, lol. Turtles are devious little devils! Of course, it would be a yummy snack for them, lol.

chris on September 15, 2011:

Can I put a couple clams into the tank with my 2 red-eared slider turtles?

fishlover on September 13, 2011:

Wow... I recently went fishing with a friend and i caught a perch a bluegill and 2 clams. I still have my perch and hes happy in his makeshift tank until i make a native one for him, the bluegill died before getting home and the 1 clam was already dead and when i put it in my fish tank it was eaten by my dojo loach i assume. But the other i put in i left on top of some sandy gravel and the next morning i use my net and find him burried and now i cant find him anymore (i assume he dug a tunnel) but anyway its my first time with clams and im at least happy.

Isadora (author) from Tennessee on August 20, 2011:

Well, if they are a cold water clam, then they should be okay. Might carry a parasite or disease though. I believe goldfish like hard water, so they would work with the clams preference in water hardness.

kitt on August 20, 2011:

thanks for the info, I just got a bunch of clams the size of my finger, I'm not sure how big they grow I got them on a river, I wonder if they are safe to put with a goldfish?

thanks

kaitlyn on July 22, 2011:

i have pet clams-i'm growing them as big as i can but so far they are about he size of my thumb

Aquaticopia on February 25, 2011:

Errg, sorry I've never used hubpages - that video was youtube > search "Asian Clam", unless this link works:

Aquaticopia on February 25, 2011:

Great info! I had always wondered if clams removed any waste *chemicals* in addition to their filter feeding.

@Darlene, when introducing the clam to the aquarium lay it on the substrate and when it feels safe (is not disturbed for a little bit) it opens up and uses a "foot" (looks like a white or pink tongue) to upright itself and feel its way into the substrate. It then wedges its way down into the substrate. As long as your substrate is deep enough, it will position itself vertically (where the two shell parts join is facing 'up & down'). You should be able to see two little syphoning holes showing up through the substrate. If your clam is laying horizontally and under the substrate - it may be dead? I linked a video of my clam when it first dug into the sand to illustrate it.

darlene on December 08, 2010:

Thank you for all this good information. At the Pet store they show the clams position up straight and mine is not its laying like a clam, is that normal? My clam is also buried. Could someone give me suggestions about the daily living habit of a clam ??

Isadora (author) from Tennessee on July 29, 2010:

Heya Sterling,

Thank you for your kind words!

I love keeping just about any kind of animal. Clams have always fascinated me--I can remember keeping them as a child. Lots of fun!

The only diving I ever did was the kind where you hold your breath and hope you don't land on a gator!

Sterling Carter from Indian Mound, Tennessee on July 29, 2010:

Wow, what an interesting Hub. I am a black water diver by trade of nearly 20 years. I have spent much of my life underwater searching for and learning about bivalves.

Here in Tennessee we have a few clams but mostly we have mussels. These are harvested for their mother of pearl. They are heavy, thick and can grow quit large.

I used to keep at least one of each species that I could legally harvest in an aquarium along with other wild caught fish.

I had to quite that when one of my larger shells, a 5 lb Washboard managed to get his foot between the silicon and the glass and broke my 200 gallon tank.

Lesson learned.

I greatly enjoyed this Hub

Thanks

Isadora (author) from Tennessee on July 29, 2010:

Hello Shad,

I advise against putting wild-caught animals into your aquarium. They carry diseases that probably aren't in your tank, this is bad for your Jack Dempsey.

If the clam dies it can wreak havoc on your system. If you do decide to keep it, I advise giving it its own container and remember to feed it!

If it were me, because of its injury, I would humanely put the clam to sleep.

I hope this helps and feel free to ask more questions. :)

shad on July 29, 2010:

i found a clam in a pond and put it in my fish tank with my jack dempsey. its about 4 to 5 in and it has a crack in its shell, is it safe to keep it in my tank and will it breed by its self thanks to who ever can answer my ?

Isadora (author) from Tennessee on April 15, 2010:

Brad,

*Yes, you can acclimate the clams just like fish.

*Algae powders can be purchased at various stores online, Ebay, or even at your local pet shop. I really enjoy using organic Spirulina, the clams eat it up quickly too.

*Mine do eat small particles of fish food but it may be difficult to get enough food for them crushed into small enough particles. They really do eat a lot and constantly! :-O

Here is the link to my clam food recipe.

Brad on April 12, 2010:

I was wondering, how do you add clams to an aquarium and how can you feed them? Do you add them like fish you add fish? To feed them when algae is not present, can I just crush up fish flakes?

Isadora (author) from Tennessee on February 25, 2010:

You're very welcome James. :-)

James on February 25, 2010:

Thank you for pointing out that clams act as animals not plants. They do not remove nitrites/ammonia; they remove suspended particles. Clams grow best in unfiltered, cloudy water.


Keeping Freshwater Clams in Aquarium

Clams make wonderful addition to any fish tank and unlike other pets they do not require special attention to fulfill their needs. They are often added to be part of an aquarium community because clams are known to act as natural filter to remove particles and leftover food debris which often get trapped among the sand and gravel bed. An aquarium designed to keep both fish and the clams should have mixture of substrates which should not be too coarse or too fine with the grain size measuring somewhere between 1 to 3mm . I would suggest you properly rinse and clean before adding the substrate to prevent unwanted accumulation of waste that might harbor viral diseases.

Coming to maintenance, I rarely have any problem having to deal with their needs. In fact these clams almost took care of themselves without even requiring my attention or supervision. Certain aquarists leave them alone without feeding any special food so that they will sift through the leftover waste and picking them up. For mine, sometimes, I will head over to the pet fish stores and try to buy for them some sinking algae wafers which they simply love to eat. One note of caution however is that, make sure that there are no dead clams being left in the tank, or else it will immediately foul the water and raise ammonia level hazardous to your aquatic community.

Freshwater aquarium clams are compatible with all tropical species and coldwater fish as they will adjust to suit the natural condition. However, what I found out is that they prefer slightly lower water temperature usually in the region of 20 to 22 degree Celsius meaning that coldwater companions will be more suitable getting along with them. There are certain fish species however which I would avoid keeping them together with my pet clams such as freshwater puffer, loaches and certain catfish species because they will end up making a good meal out of them.

Information provided by one of our loyal readers.
Thanks Mark, appreciate it!


Caring For Tridacnid Clams

Tridacna maxima Photo: Keith Berkelhamer

Giant Clams, both the Hippopus Clams and the Tridacna Clams, are beautiful, hardy, grow rapidly, and require little care!

  • Reef Aquarium Setup
    Aquarium Parameters
    Lighting Tips
  • Giant Clams for Sale:
    What to Look for When Purchasing Giant Clams
  • Placing Giant Clams In the Reef Tank
  • Giant Clam Care
    Feeding Giant Clams
    Nutrients for Giant Clams
  • Giant Clam Hitchhikers:
  • Giant Clam Predators and Pests:

All of the above is true when speaking of a clam that is already well adapted to your aquarium. As with all pets (in your tank or otherwise), they must be taken care of properly in order to actually live up to those claims. Once established a giant clam makes an awesome addition to a reef aquarium. Though like all reef inhabitants, it will need good water quality and proper lighting, it will require little else in the way of care.

Giant clams can give you a number of years of enjoyment, however the initial adjustment to your tank can be a considerably difficult time. The differences in lighting, pH, temperature, salinity, water current, and more can be drastic to the new clam. It's important to be as well prepared as you possibly can for the care of your clam before actually purchasing one.

Try to purchase farm raised giant clams instead of collecting them from the wild. Tridacnid clams have been exterminated in many areas because of over harvesting, collected for food and shells.

The mariculture of tridacnid clams was begun to re-stock areas where the clams had been eliminated, and to provide a farm raised source of clams for food. A portion of the farm raised clams now goes to the aquarium trade. Profits from the demand of aquarists has raised interest in producing colorful varieties of all the species. Ask your fish stores and online sellers for farm raised clams.

The Crocea Clam reaches sexual maturity around 3" and/or 4 to 5 years. They will shoot out their sperm or eggs every 2 minutes. A good skimmer to help rebalance the water parameters will help if one of these events occurs. SPS tanks with about 2 ppm of nitrates is the perfect environment for your clam.

The Derasa Clam is one of the easier clams to care for with a few notable facts. First, they are able to get by with moderate light, unless they are bright blue (rare coloring) and will do fine with Metal Halides, intense LED and strong T5s. They are still for intermediate aquarists who can maintain stable and clean water parameters. Acclimate them to a bright aquarium's lights slowly and over about a weeks time. They will grow 3" per year, so where they are placed will eventually be taken over by an 18 to 24" clam! Uh, no they are not a good choice for nano tanks! The coloring on this clam is a perfect example of a Derasa's warmer tones, mixed with iridescent accents and stripping.

The Gigas Clam has been known to grow to 4 feet, weighing around 500 pounds. The record is 4.5" and over 750 pounds, which emphasizes the reason that these clams are best left in the ocean to clean the water there. Living over 100 years long, if a clam out lives it's owner, is it unlikely a new owner beyond an aquarium would take the clam. Once they reach 12" and there are fish in the tank and the light is strong, feeding them is not as necessary, however the nitrates SHOULD be at least 2ppm.

This video shows that Maxima Clams are like fingerprints, in that no two ever look the same! They have light sensors on the mantle and do need a lot of lighting. Keep your tank kelvin range from 6K to 10K for best results. They do best in a tank that is at least 100 gallons. Maxima Clams can live over 200 years and will reach 14" around 70 or 80 years, however most do not live that long in captivity and will more than likely grow to around 8 to 9" in most aquarists tanks during their first 30 years.

Squamosa Clams usually will reach around 12" in captivity. They can reach almost 18," although it will take 60 to 70 years to do so! This video shows the beauty of the Squamosa Clam in great detail. Provide a tank that is at least 100 gallons for stable water and very strong light. These are considered a beginners clam, and strong light, an at least 6 month old tank and only turbulent water flow that can be low to high is required. Straight water shooting from a pump will cause the clam to eventually die over time for various reasons. The beauty of this clam is also seen in it's shell!

The Hippopus or Bear Claw Clam is only one of two clams in this genus, Hippopus. They typically grow to 16," so they will need a 100 gallon tank, stable water, moderate to strong lighting and low to high water flow that is turbulent, not linear. These are the most durable of the clams, suitable for beginners that can handle a 100 gallon system. They have very attractive shells, demonstrating beauty inside and out!

  • Temperature: Mid to Upper 70° F. (mid 20° C.). Do not let the aquarium exceed 84° F.
  • Salinity / Specific Gravity: 1.024. Salinity is also important, too high or low a salinity can cause the death of a clam. Try to keep specific gravity between 1.023 and 1.025.
  • pH: 8.3. Do not let the aquarium exceed a pH above 8.4.
  • Hardness: Maintain a dkh of 7.9.
  • Water Movement: For most giant clams low to moderate currents will be tolerated.

Giant Clams will do well under moderate to relatively high lighting intensities. They don't particularly like intense lighting nor will they tolerate sudden increases in intensity. Take great care if attempting to acclimate them to intense lighting such as metal halides. T. gigas can be adapted to metal halide lighting, but this should be done over time as a gradual process.
When determining the lighting needs of your clam, a few basic things to consider are placing it in the aquarium, its mantle color, what species of clam is it, and its needs as it ages:

Lighting tips for keeping giant clams:

  • Placing giant clams:
    With brighter lights, you can place your clams lower in the tank. With lower intensity lights, you will be forced to place them near the surface.
  • Giant clam species - lighting needs:
    Light requirements are different for the different species of clams:
    • The Crocea Clam T. crocea and Maxima Clam T. maxima need the most light..
    • These are followed by the Gigas Clam T. gigas , Derasa Clam T. derasa , and Squarmosa Clam T. squamosa .
    • The least amount of light is needed by the Hippopus Clam H. hippopus .
    Â Â Most clams need a lot of blue light in the bulb's spectrum. The Derasa Clam T. derasa needs less blue light than Gigas Clam T. gigas and Maxima Clam T. maxima .
  • Clam mantle color - lighting needs:
    Clams with brown mantles do not require as much light as those with blue mantles, usually, and are considered easier to keep in the home aquarium lighting wise. Clams with blue mantles are usually found in shallow-water. The blue pigment acts as a light filter and so they require substantial quantities of light.
    A good rule to stick to is, the more colorful the clam, the greater quality and quantity of light it will need.
  • Giant clam ages - lighting needs: :
    As the clam grows, its mantle will thicken and the number of zooxanthellae will increase (with the deeper lying zooxanthellae receiving less light) and it will require more and more light.
    Smaller clams, those less than 1.56 inch / 4.0 cm, require less light to maintain their optimum growth while the larger clams require more light. Also, juvenile clams will adapt to lighting variables more readily than adult clams.

Changes in lighting / environment - effects on giant clams:

When you take a clam from the sea and place it in the aquarium, the difference in the spectral composition of the light can have drastic impact on the clam's food supply. A clam at sea receiving the full light spectrum transferred to a tank with the same light intensity, only with blue wavelengths dominating, is receiving the same amount of light but some wavelengths are missing and others are in greater quantities.
Depending on the clam's adaptation, some of the zooxanthellae's assimilation pigments may cease to function and pigments that would use the new wavelengths aren't even present. Basically in this situation, the new lighting is incorrect for the clam even though the intensity of the illumination is the same as before. The clam can adapt to the new spectral composition, slowly, but the time needed for this to occur may be too long.
This leaves the clam weakened, with less resistance to defend against predators, diseases, etc. Smaller clams require less light.

What to look for when purchasing Tridacnid clams - what to know about giant clams for sale:

  • Watch for gaping Clams:
    Recently imported or transported clams usually exhibit a behavior called gaping. A gaping clam will appear as follows: shell fully open, mantle poorly extended, and inhalant siphon widely stretched. This eventually passes.
    Gaping will continue if the clam is kept under insufficient lighting, is damaged, or unhealthy. The mantle will begin to pull inwards, shriveling and tearing between the siphons. A healthy clam's inhalant siphon can open wide sometimes, but gaping leaves a very wide opening.
    The clam will stay like this for as long as the clam is unhealthy.
  • Examine the mantle:
    The clams mantle should be colorful everywhere with no clear or white areas. Colorless areas may be the result of poor lighting, predators, or disease. A clam will quickly recover from poor lighting once conditions are improved. NOTE: It is normal for T. gigas to have clear areas near the center of their mantle.
    Also check for rips and tears in the mantle. A healthy mantle should be extended over the edge of the shell and not pulled inwards. NOTE: It is normal for H. Hippopus' mantles to not extend over the shell.
  • Check the clam's reactions.
    A healthy clam should react to external stimulus by forcefully closing its shell. Newly imported and transported clams tend to react more slowly, but will improve as they regain their strength.
  • Check the clam's byssus gland:
    The byssus gland should be undamaged. You should not see any torn or loose tissue hanging from the bottom of the clam. Some byssal strands may be visible, but no solid tissue hanging loose.
    Byssal gland damage isn't always visible, however. The clam may appear fine for a couple of weeks and then die suddenly for seemingly no reason.
    On the good side, byssal gland damage isn't always fatal. According to The Reef Aquarium Volume One, Delbeek and Sprung have collected and purchased damaged clams with little loss.
  • Removing a giant clam:
    If the clam is attached to substrate, please take care when detaching. Lift the shell gently and insert a sharp knife, razor, or scissors and cut the threads as close as possible to the substrate. Do not cut close to the shell. You could cut into the extended byssal gland. If the clam is attached to a small rock, pebbles, etc., just leave it alone.
    The Crocea Clam T. crocea and Maxima Clam T. maxima are very sensitive about being handled like this and are best left attached if possible.

Farm raised giant clams: Hatchery (culture/farm) systems for giant clams are setup basically the same. Baby clams only live a short time in tanks. Once the clams reach 0.75 to 1.25 inches (20 to 30 millimeters) they are moved to ocean nurseries. They spend the rest of their growing time, until they reach about 1.5 inches (4 centimeters) or more, in the ocean. This is true for majority of the clams, regardless of their species, that are marketed to the hobby. So, even the farm raised clams are from the sea!

A hint for clam sellers: A good way to display clam stock would be to place them on small cups or pots filled with crushed coral.

  • This way the clam will only attach to the gravel. This makes it very easy to remove the clam when sold and with much less stress on the clam and its byssal threads and gland. There is also less stress on a seller who has to dismantle their display to detach the clam while the customer stands around waiting.
  • Rinse the gravel routinely to prevent worms from moving in.
  • The pots will also help keep the clams upright and positioned properly under the light source.
  • Dealers can also hang a mirror above the aquarium (at a 45 degree angle). The customer will then see the true colors of the clams without having to contort themselves.

Placing Giant Clams In the Reef Tank

When putting your clam in your tank there are a few placement considerations:

  • Clam movement :
    Once placed, clams generally cannot move around on their own. This is why where you put them in your tank is of vital importance. Clams placed on hard surfaces (rocks) will not be able to upright themselves or shift their positions. Clams on sand can manage to upright themselves or shift positions with small movements.
    Don't expect your clam to move any great distances. Juveniles clams settle permanently, only using their foot to travel short distances.
    Generally the larger the clam, the less moving around you should expect, which basically means your clam's place in your tank and its happiness there is really up to you.
  • Closing clam shells :
    Clams can close their shells with enough force to expel a surprising amount of water out of their siphons. If you place your clam near the top of your tank, this water may be expelled out of the tank or up into your lighting system.
    Clam's may also accidentally trap small, slow moving fish that rest on their mantle (for example, mandarins, gobies, hawkfish, or blennies).
  • Surface - flat or inclined:
    Find as flat a surface as possible and place the byssal opening flat on the substrate with the mantle facing directly up.
    Horizontal surfaces are best for clam placement. If you insist on putting your clam on an incline, make sure the byssal opening is on the lower portion of the substrate. If the incline is too great, the clam will not receive enough light, so do not place it on steep substrate.
  • Substrate types:
    A clam may fall over several times before it firmly attaches to the substrate. A good idea is to put some small rocks (crushed coral, large pieces of substrate, etc.) around the clam to help it stay upright. These small rocks will not get in the way of the opening and closing of the shell.
    Your clam will attach within a few days to a week. Substrate is not related to attachment speed. Once your clam is attached, you can remove the rocks, unless the clam has used them in its attachment.
    Do not place your clam between large rocks, inside small holes, or up against the tank wall, or you may prevent them from opening fully.
    • The Crocea Clam T. crocea and Maxima Clam T. maxima are found in rocky habitats so it is best to place them on rocks. .
    • The Squarmosa Clam T. squamosa , Derasa Clam T. derasa , Gigas Clam T. giga s, and Hippopus Clam H. hippopus are best placed on sandy substrates.
  • Lighting requirements:
    Remember the lighting requirements of the clam you are putting in your tank. Clams with colorful mantles need a great deal of light. Clams with brown mantles, not as much light. If your clam has a brown mantle, place it nearer the bottom of your tank, or shield it (an overhang would work well for this) from strong lighting if you have to.
  • Giant clam position:
    Don't leave a clam that has fallen over, upright it as soon as possible.
  • Inhalant siphon:
    Place the clam so the inhalant siphon (which lies above the byssal opening) is on the lowest portion of the slope. As the clam grows it will place greater strain on its byssal gland, so if the gland is on the upper portion of the slope, the weight of the clam could gradually pull the gland out. Adult Hippopus sp . tend to sit more on their hinge than on the byssal opening.
  • Mantle:
    Giant clams should be placed so that the majority of their mantle is facing upwards. Juveniles will attach themselves to rocks with byssus threads just as other tridacnid clams do.
  • Currents:
    GIant clams do not like strong currents, especially the Crocea Clam T. crocea . Do not place them where they would receive strong, direct water currents. Too much current will cause your clam not to open. They do need water flow to bring nutrients to them, just not too strong.
  • Tank mates:
    Keep your clam as far away from any aggressive coral or anemone as is possible in your tank. If sections of the mantle are pulled away or shriveled on the same side as a coral or anemone, it is probably irritating the clam and move the coral, anemone, or clam as soon as possible. Do not hesitate, or it will die quickly.

With proper lighting and careful attention, giant clams require little else in the way of care. It is important to make sure they are not being irritated, not being fed upon by other organisms, and good water quality must be maintained. Giant Clams can be kept in a reef environment with live rock and coral substrates. The number one cause of a giant clam's demise is usually water quality. A high pH and high temperatures can cause problems.

  • Giant clams receive the majority of their nutrition from their zooxanthellae, whether additional feeding is required is still debated. Some hobbyists believe that tridacnids should be fed, going on the assumption that they are filter feeders like other clams.
  • According to The Reef Aquarium Volume One, when Delbeek and Sprung attempted to feed the clams, they closed forcefully and expelled the food. They may accept a dilute suspension of live phytoplankton or a yeast. However, the effort required to feed these items is not worth it in the opinions of Delbeek and Sprung. Delbeek and Sprung noted that for many years, Tridacnid clams have been grown successfully in both culture systems and home aquaria without any supplemental feedings. They noted that bacteria, organic and inorganic compounds are always present in the water of closed systems (like our tanks), and these may be consumed or absorbed by the clams.
  • Of opposing opinion, Albert Thiel noted that in some cases supplemental feeding may be necessary. What those "cases" are was not mentioned. Mr. Thiel further notes that small foods should be used and that clams do not feed on large chunks of food. Use good quality food like shrimp or scallop meat run through a blender.
  • For more detailed information about the nutrition and feeding requirements of clams see:
    Giant Clams - What Do Clams Eat?

Basic Nutrients for giant clams:
Basic nutrients in the aquarium that these giant clams need are calcium, strontium, iodine, magnesium, and possibly a minute amount nitrate.

  • Calcium: Calcium is the main building block for clams and should be present in the water at levels of at least 280 mg/L for growth to occur. More rapid, natural growth is seen when calcium is in the range of 400-480 mg/L.
  • Strontium: Strontium is incorporated in the shell along with calcium and should also be provided for optimum growth.
  • Iodine: The addition of iodine to the aquarium will also enhance growth and color in giant clams.
  • Magnesium: Magnesium aids in maintaining proper calcium levels and in the formation of skeletal material in clams
  • Nitrate: They require some nitrogen for proper growth. Nitrate can be added if levels are extremely low, but be careful as nitrates should never exceed 2 mg/L.

What might be hitching a ride on a giant clam:

  • Clam shell with encrusting organisms:
    Clam's sometimes arrive with growths of encrusting organisms on their shells, especially the Maxima Clam T. maxima and Squamosa Clam T. squamosa . Check these growths very carefully. Dead or necrotic areas may foul your tank.
  • Parasitic snails:
    Various parasitic snails can be imported with your clam. They are carnivorous boring snails and that description should be enough for you to want them out of your tank and as far away from your clams as possible.
    Look for small rice grain-sized, cream colored spots near the base or hidden within the flutes (the grooves and indentations in the shell) of the shell, or, at night, along the upper edge of the shell. If the clam is attached to a rock, check by lifting the clam a short distance off the rock and look underneath. You are looking for small (0.08-0.2 inch / 2-5 mm long) snails. Remove all of these snails.
  • Quarantine giant Clams:
    If you have the facilities, quarantining your clam until you are sure all the snails are removed is a good idea. Also check for the egg masses of these snails and remove them as well. They are small, jelly-like masses on the shell. Don't confuse the jelly-like mass some clams excrete around their byssus opening for these egg masses .Keep looking for these snails. Just because you think you got them all when you added the clan to your tank doesn't mean you really did!
  • Safe shrimps and crabs:
    Symbiotic shrimp from the family Palaemondidae ( Anchistus , Conchodytes and Paranchistus ) or small crabs such as Pea Crabs of the family Pinnotheridae may be visible through the inhalant siphon in larger clams.
    These animals live inside the clam and do not harm it, although what they eat and what they do for the clam is unknown.

Giant Clam Predators and Pests:

In the wild, small tridacnid clams are heavily preyed upon. Many species of fish (triggerfish, large wrasses, puffers, etc.), crabs, lobsters, shrimp, polychaetes (Bristleworms, Fireworms, etc.), octopi, and snails prey on clams. Even burrowing sponges! Since most of the clams available to aquarists are juveniles, hobbyists should be extra cautious about both predators and environmental factors that can wreak havoc with a clam.

  • Fish Predators:
    Certain wrasse species (Family Labridae ) are bad tank mates. Species like the Twin Spot Wrasse Coris aygula and Bird Wrasse Gomphosus varius have been known to attack and devour juvenile clams in the aquarium. Sometimes the clam is eaten from above or knocked over and eaten through the soft and unprotected byssal opening. Any large wrasse species should be watched closely when introduced into a tank with giant clams.
    Other fish can also irritate clams. Fish that are constantly grazing like as Centropyge sp. (Pygmy Angelfish), Ctenochaetus sp. (Chevron Tang, etc.) and Acanthurus sp. (Achilles Tang, etc.) Tangs, and Ecsenius sp. (Blennies) will occasionally nip at a clam in passing.
    Sometimes small pieces of tissue are removed but the problem is that the clam is now irritated and it will expand less and less. It may eventually expand so little that it won't receive enough light and will slowly die.
  • Crab Predators:
    Large crabs will eat clams and usually shortly after they are placed in the tank, before they can attach to the substrate. They attack the clam through the byssal opening, but larger crabs just crack the shells open.
  • Shrimp Predators:
    Certain species of shrimp can also prey on clams. Large shrimp such as Marble Shrimp Saron marmoratus and Buffalo Shrimp Saron sp. will attack clams at night.
    The common Cleaner Shrimp Lysmata amboinensis has been known to attack clams. It's rare, but it does happen, especially when the clam is injured and the shrimp hungry.
  • Snail Predators :
    Parasitic snails are sometimes imported with tridacnid clams as mentioned earlier. Examine new clams closely and remove any snails or eggs right away.
  • Environmental factors:
    A number of environmental factors can also irritate giant clams, creating potential problems:
    • Algae:
      Algae is another problem for clams. If algae begins to grow over the lip of the shell, the mantle may become irritated and it will not expand as much.
    • Macroalgae:
      Macroalgae like Caulerpa can irritate the clam from underneath if allowed to grow under the byssal opening. If this happens, the clam will produce large amounts of mucus from below that surrounds the base.
    • Clam Mucus:
      Producing large amounts of mucus is a normal means of protection for the clam against algae, stinging corals, or predators. The mucus is thick, clear, and often contains brown patches (brown jelly). The effect of noxious by-products of soft corals (example: Xenia spp.) can also cause clams to produce large amounts of clear mucus. The mucus can quickly clog prefilters
    • Aiptasia anemones:
      If Aiptasia are allowed to grow on tridacnid clams, they can reach underneath the mantle and sting the clam. This will result in the mantle pulling away and the clam will eventually die.
    • Clam worms:
      Polychaete worms such as the larger Nereis sp. and Eunice sp. can prey upon tridacnids. They are usually active at night and feed on the clam from below, through the byssal opening or by boring a hole through the shell.
    • Air bubbles:
      Air bubbles can be a problem too. They can become trapped inside the clam and cause the clam's demise.
  • For more information on giant clam predators and pests see:
    Tridacnid Clams: Friends, Enemies & Ailments

Authors: Elizabeth M. Lukan / Clarice Brough, CFS.

Copyright © [Animal-World] 1998-2020. All rights reserved.


How to Keep and Care for Freshwater Clams in Aquariums - pets

This picture shows a Freshwater Clam.
These are Fun !!
Please read the important
email below on this page.

Appropriate Home
An aquarium with an external power filter with a BIO-Wheel, and a maximum of 1/4-inch of gravel.

We know that these clams do well from 65 to 82 degrees F., so they will do well in both cool water aquariums without a heater and warm water aquariums with a heater.

Click here for more about cool water aquariums, or click here for more about warm water aquariums.

Freshwater Flat Clam
Size: 2" to 3" long
More Fun !!
Please read the important
email below on this page.

Recommended Diet
These clams are filter feeders, filtering what they eat from the water that they live in. They seem to do well in aquariums, and we have kept them for many months.

Size and Lifespan
These clams are usually about 1" to 1.5" across the shell, but we have heard that a few are as big as 2" across the shell. We don't know how long they can live, but they can live for at least a few years.

Unfortunately, when people tire of aquarium species - or they become problematic they elect to 'dump' them into a pond or lake rather than finding them a home or digging a hole and burying them. Aquarium dumping is a major pathway for invasive species.

One good example of what can happen is the snakehead problem that has been recently made national headlines. The hundreds of thousands of waterbodies across the US that are infested with elodia, milfoil, salvinia, azola and other aquarium plants are another prime example of aquarium dumping that is costing the taxpayers billions each year for control and eradication.

You have a wonderful website and I will no doubt purchase some cichlids from you in the future. However, I would encourage you - and other mail order houses - to include information that explains why these animals and plants should never be put into public waters - or even into private ponds where there is a chance that flooding may spread them into public waters.

We know that that we must responsible or the government will have to make more laws that limit the kinds of pets we keep.


Author: Giovanni Carlo

I am a koi fish keeper and breeder a husband of beautiful wife Maybel and beautiful daughter May Carl I have been in fish keeping hobby for over 35 years. Like many kids in the 80's We catch fish in the rivers and canals and kept it in the "pasong" local visayan name for pond. or a large mayo bottle since We don't have aquariums yet on that time. decades later their is a small petshop open in my place and that starts me from buying aquarium and fishes that are sold in the pet store decades later start growing goldfish and koi fish until today. View all posts by Giovanni Carlo


Watch the video: Unboxing 10+ FreshWater CLAMS for My Aquarium!! (July 2021).