Reef Aquarium Tridacna Clams – maxima, crocea, squamosa, and gigas

Reef Aquarium Tridacna Clams – maxima, crocea, squamosa, and gigas


What’s up guys… let’s talk about clams. Giant clams of the Genus Tridacna are a popular
mollusk in reef aquariums. Most people that aren’t into this hobby are familiar only
with the shells of clams. It’s a shame because their true beauty can only be realized when
they are living as they have a brilliant mantle that is stunning to behold. Tridacna clam mantles have intricate patterns
and come in a variety of colors. I’ve seen clams that are purple, blue, green, yellow,
and even some even have iridescent qualities. It is not difficult to understand why these
clams are so popular in the reef-keeping hobby. Tridacna clams are found all throughout the
Pacific. The four most readily available species of Tridacna clams are derasa, squamosa, maxima,
and crocea. In rare instances one might find the true giant clam, Tridacna gigas. Here
is a 30-year old gigas at the Waikiki aquarium in Hawaii. It was grown from a tiny specimen
less than an inch to this monster that weighs hundreds of pounds. There are actually two other species that
are not in the aquarium trade namely T. tevoroa and T. costata which is a new species discovered
in the Red Sea. Let’s talk a bit about their anatomy. The mantles are filled with zooxanthellae
much like photosynthetic coral. Early in a clam’s life the quantity of zooxanthellae
is limited so they rely more on filter feeding. It is estimated that smaller clams get 65%
of their energy from filter feeding. Larger clams only get 34% of their total carbon from
filter feeding indicating a much greater reliance on photosynthesis. As a general guideline,
clams smaller than 3” would benefit from phytoplankton supplementation. Lighting is probably the single most important
factor to consider when keeping clams. Second to lighting is the need to maintain tip-top
water chemistry. High calcium and alkalinity are a must. Clams are known for fast growth
rates and deplete calcium and alkalinity aggressively to power this growth. This is why they tend
to do better in tanks designed for corals like Acropora, which also require high light
and ample supply of major elements for calcification. As for flow, these clams prefer moderate flow
despite originating from shallow areas on the reef that receive heavy wave action. The
concern with high flow in the aquarium is the risk of introducing bubbles into the body
that the clam cannot effectively eliminate. Clams have two siphons that move water in
and out of its body. There is a large Inhalent siphon lined by fine tentacles. When it opens
wide, you can catch a glimpse of the clam’s gills. The gills of the clams are interesting
in that they are used for both respiration and feeding. The water then is expelled through a smaller
exhalent siphon. The exhalent siphon is also used to expel waste from the clam as well
as discharging sperm and eggs for reproduction. At the base of the clam is a foot by which
it attaches to the substrate. There is also a byssal organ that excretes a thin byssal
threads to anchor it into place. It is critically important that the aquarist does not damage
the foot or the byssal gland moving a clam from one place to another. It is easy to damage
the byssal organ and if it happens, chances are the clam will die. Once a clam is anchored
to a rock it is best to move the clam and rock together. Now that we’ve covered the common anatomical
features of Tridacna clams, how do we tell the different clams apart? Let’s start with
Tridacna maxima and Tridacna crocea because they are by far the most similar to one another.
They both have dazzling multi-colored mantles. The best way to tell them apart is the shape
of their shells. Maxima clams are slightly elongated in shape while croceas are more
stout and stubby. Also, maxima clams tend to have more pronounced flutes on their shell
compared to croces clams that are a little more smooth in texture. Crocea clams are called boring clams because
they are able to dissolve the nearby coral substrate leaving only their mantle visible.
At their base they can secrete a mild acid that over the years erodes the calcium carbonate
substrate kind of like how a calcium reactor dissolves media. Like just about every sessile organism on
the reefs, clams are looking to clear out real estate for their personal growth. Some
have observed that not only are clams capable of releasing a mild acid at their base to
bore down into rock, they are also capable of releasing acid through their extended mantle
to kill off nearby coral. Tridacna derasa are much easier to tell apart
from the other clams. Derasa clams have a distinctive golden colored
mantle with streaks of teal and a vibrant blue rim. In comparison to maxima and crocea
clams, derasa clams get massive. It is not uncommon to have a derasa grow to over 20”
in a home aquarium. They are considered one of the more hardy clams making it an ideal
choice for a first time clam enthusiast. That brings us to Tridacna squamosa.
While less common than the other three clams, the occasional squamosa turns up from time
to time. Squamosa clams have muted coloration in comparison to maxima and croceas but have
a distinctive fluted shell. While maximas, croceas, and derasas have somewhat smooth
shells, the squamosa has pronounced scales that are quite attractive in their own right. One day I would like to try and aquaculture
clams. We are a long way off from doing anything like that, but they are such cool animals
and it is possible to get them to reproduce sexually by manipulating light, hormones,
and chemical parameters in the water. Most of the places doing it now are doing it with
mariculture setups out in the ocean or hybrid facilities on the coast. I think in the next
few years there will be a lot of progrWhat’s up guys… let’s talk about clams. Giant clams of the Genus Tridacna are a popular
mollusk in reef aquariums. Most people that aren’t into this hobby are familiar only
with the shells of clams. It’s a shame because their true beauty can only be realized when
they are living as they have a brilliant mantle that is stunning to behold. Tridacna clam mantles have intricate patterns
and come in a variety of colors. I’ve seen clams that are purple, blue, green, yellow,
and even some even have iridescent qualities. It is not difficult to understand why these
clams are so popular in the reef-keeping hobby. Tridacna clams are found all throughout the
Pacific. The four most readily available species of Tridacna clams are derasa, squamosa, maxima,
and crocea. In rare instances one might find the true giant clam, Tridacna gigas. Here
is a 30-year old gigas at the Waikiki aquarium in Hawaii. It was grown from a tiny specimen
less than an inch to this monster that weighs hundreds of pounds. There are actually two other species that
are not in the aquarium trade namely T. tevoroa and T. costata which is a new species discovered
in the Red Sea. Let’s talk a bit about their anatomy. The mantles are filled with zooxanthellae
much like photosynthetic coral. Early in a clam’s life the quantity of zooxanthellae
is limited so they rely more on filter feeding. It is estimated that smaller clams get 65%
of their energy from filter feeding. Larger clams only get 34% of their total carbon from
filter feeding indicating a much greater reliance on photosynthesis. As a general guideline,
clams smaller than 3” would benefit from phytoplankton supplementation. Lighting is probably the single most important
factor to consider when keeping clams. Second to lighting is the need to maintain tip-top
water chemistry. High calcium and alkalinity are a must. Clams are known for fast growth
rates and deplete calcium and alkalinity aggressively to power this growth. This is why they tend
to do better in tanks designed for corals like Acropora, which also require high light
and ample supply of major elements for calcification. As for flow, these clams prefer moderate flow
despite originating from shallow areas on the reef that receive heavy wave action. The
concern with high flow in the aquarium is the risk of introducing bubbles into the body
that the clam cannot effectively eliminate. Clams have two siphons that move water in
and out of its body. There is a large Inhalent siphon lined by fine tentacles. When it opens
wide, you can catch a glimpse of the clam’s gills. The gills of the clams are interesting
in that they are used for both respiration and feeding. The water then is expelled through a smaller
exhalent siphon. The exhalent siphon is also used to expel waste from the clam as well
as discharging sperm and eggs for reproduction. At the base of the clam is a foot by which
it attaches to the substrate. There is also a byssal organ that excretes a thin byssal
threads to anchor it into place. It is critically important that the aquarist does not damage
the foot or the byssal gland moving a clam from one place to another. It is easy to damage
the byssal organ and if it happens, chances are the clam will die. Once a clam is anchored
to a rock it is best to move the clam and rock together. Now that we’ve covered the common anatomical
features of Tridacna clams, how do we tell the different clams apart? Let’s start with
Tridacna maxima and Tridacna crocea because they are by far the most similar to one another.
They both have dazzling multi-colored mantles. The best way to tell them apart is the shape
of their shells. Maxima clams are slightly elongated in shape while croceas are more
stout and stubby. Also, maxima clams tend to have more pronounced flutes on their shell
compared to croces clams that are a little more smooth in texture. Crocea clams are called boring clams because
they are able to dissolve the nearby coral substrate leaving only their mantle visible.
At their base they can secrete a mild acid that over the years erodes the calcium carbonate
substrate kind of like how a calcium reactor dissolves media. Like just about every sessile organism on
the reefs, clams are looking to clear out real estate for their personal growth. Some
have observed that not only are clams capable of releasing a mild acid at their base to
bore down into rock, they are also capable of releasing acid through their extended mantle
to kill off nearby coral. Tridacna derasa are much easier to tell apart
from the other clams. Derasa clams have a distinctive golden colored
mantle with streaks of teal and a vibrant blue rim. In comparison to maxima and crocea
clams, derasa clams get massive. It is not uncommon to have a derasa grow to over 20”
in a home aquarium. They are considered one of the more hardy clams making it an ideal
choice for a first time clam enthusiast. That brings us to Tridacna squamosa.
While less common than the other three clams, the occasional squamosa turns up from time
to time. Squamosa clams have muted coloration in comparison to maxima and croceas but have
a distinctive fluted shell. While maximas, croceas, and derasas have somewhat smooth
shells, the squamosa has pronounced scales that are quite attractive in their own right. One day I would like to try and aquaculture
clams. We are a long way off from doing anything like that, but they are such cool animals
and it is possible to get them to reproduce sexually by manipulating light, hormones,
and chemical parameters in the water. Most of the places doing it now are doing it with
mariculture setups out in the ocean or hybrid facilities on the coast. I think in the next
few years there will be a lot of progress made on trying to grow clams inland and I
personally think it would be an exciting project. Anyhow, that does it for Tridacna clams. I
hope you guys enjoyed the video. Until next time, happy holidays, and happy reefing.
ess made on trying to grow clams inland and I personally think it would be an exciting
project. Anyhow, that does it for Tridacna clams. I hope you guys enjoyed the video.
Until next time, happy holidays, and happy reefing.

39 thoughts on “Reef Aquarium Tridacna Clams – maxima, crocea, squamosa, and gigas

  1. I've got a clam that I wasn't sure what kind it was but after watching I'm pretty sure its a maxima. The only thing that threw me off from me thinking it wasn't a maxima was because it's mantle was tan and not the common blue/purple. Maybe it could be a squamosa?

  2. Acro Al has done this successfully from home from Australia. He has breed some very nice specimens. A lot of cool maxima variants the world has never seen up until recently..

  3. I've been waiting for this video! Great job Than, your videos are very informative and entertaining. Would you recommend a Maxima Clam in a 38G mixed reef? Thanks.

  4. Hi, I have managed to get them to spawn twice now using 3 banks of AI's on the moon cycle.

    Not great though, almost wipes my tank every time.

    Good luck! Keep us updated

  5. after watching I have a much better understanding of clams and there care thanks so much

  6. There is a sale this weekend at my Lfs for a squamosa clam for 34 dollars,. Is this a good deal. They are about two inches.

  7. Great video!! Thanks! I'm thinking of getting a small Derasa clam pretty soon. What are the clam's natural predators? Any fish/inverts I should avoid if I wanna keep a clam?

  8. Hey dude. I'm sure you know by now but younger clams don't rely on filter feeding more than older ones. This is a myth.

  9. I first met the big black giant clam in the ocean and it was a bit scary (because I did not know anything about them before) but enormously fascinating

  10. Wouldn't it be awesome if the pigments in our skin were made up of cells that could perform photosynthesis? It would solve quite a few problems around the would especially for people who live in hot sunny countries we're faming is a huge problem. People would rely more of fresh water than food. It should also cut the production of agriculture as we would need to eat less…

  11. Way back in 1980's, we export the meat of T. Crocea and Maxima to Japan for food consumption, but later on the government banned the exportation, because these 2 specie of clams are belongs to Giant Clams and is embedded in the Corals, so that when the fishermen get the meat, they can destroy the Corals which we protect for fish as their dwelling place, so we started to culture these 2 specie by sea ranching. I observe that variation of colors of T. Maxima and Crocea came from sunlight. Giant clams is rich in protein and it is considered aphrodisiac so that it is in demand in Japan market. I agree on farming and propagation of GIANT CLAM. Thank you for sharing the techniques of culturing clams.

  12. so where would you place them in the tank? can they go on a lower rock, or do they have to be in the substrate?

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