Livestock Profile: Tridacnid Clams

[NateHanson]

How about a thread like Moe's "How Does it Work" equipment threads, but concentrating on a category of livestock we keep in our tanks?

I know very little about keeping Tridacnid clams, and I'd like to prod some of the experienced folks to discuss the types of clams, what environments are suitable for them, and how to take care of them on a regular basis.

Nate

 

[Moe_K]

Great idea, Nate.
If we get good content I'll stick this in w/ the useful threads too.

 

[_Eric_]

I wrote this a long time ago...Maybe this will help.
First of all I would like to thank you in advanced for reading my article on clams..

After you read this article this should give you a better understanding on saltwater clams.

Here are some words that are associated with clams and there definitions that will help you on your way as well.

#Larvae__The newly hatched stage of any of various animals that differ marked in form and appearance from the adult.

#Byssus Gland__The structure in clams that produces fibrous threads{byssus} that attach the clam to substrate.

#Iridophores__Fixed cells in Tridacnid clams that contains numerous UV protection pigments.

#Hyaline Organs__ Clear areas in the mantle of Tridacnid clams that appear to focus light onto dense aggregations of zooxanthellae.

#Mantle__Large, pigmented fleshy portion of Tridacnid clam that is exposed to the light by gaping of the shell valves. Also called "Siphonal tissue".

#Siphon__The inhalant and the exhalant siphons of the Tridacnid clams are used to allow for gas exchange and to expel waste.

#Siphonal tissue__Another description of the mantle

#Palps__Flap/like structures in clams that direct food towards the stomach.

#Phytoplankton__Microscopic algae which is suspended in the part of the water column that is penetrated by light.

#Ultraviolet{UV}Light__Ultraviolet is a high energy, short wavelength of light. It is shorter than violet in the visible spectrum and on the border of the X-ray region.

 

[_Eric_]

This is some info on Tridacinds that you should know as well.

They all have two ""valves"" shells like all normal clam have. The difference between the normal clam and the Tridancinds are they have the presence of Zooxanthellae in them. The mantle on the Tridacinds increases the surface area when available for exposure to the light.

The mantle contains the majority of the Zooxanthellae as well as fixed cells called iridophores that contains pigments and these pigments are mostly in the color range of blue, green, brown, and yellow.."I feel there are a few more colors but thats beside the fact. :wink:.. Thats why there is a large amount of colors and patterns in these calms.

Pigments are the main function on protecting the clams from excessive light and UV radiation.

 

[_Eric_]

If your Tridacnids does not receive the proper light intensity or even the quality, they will loose there bright colors. When they loose there bright colors, the brown color of the Zooxanthellae becomes very visible to the eye. If you catch this soon and are able to improve the conditions immediately you can regain the clams health.
If not the next step you will see is the clam taking on a color of whitish-brown. This is called Bleaching, once this has taken place death will follow.
Another thing that can cause Bleaching is the lack of Iodine.


There inhalant sipon is made up of an elongated opening. Fringed tentacles sometimes surround this opening. These tentacles strain out large particles. There exhalent siphon forms a raised cone which can be found further along the mantle from the inhalant siphon. After the water is filtered it leaves the clam gills though the exhaled siphon.


If you end up purchasing one of these inverts make sure you place something under them. You will see why after you read the rest of my article.


The Tridacnid will form a foot..(Called a Byssus) this byssus will be formed next to the hinge of the valves. This byssus gland produces filaments called byssal threads that will extend though the opening between the two valves and "Thus" allowing the clam to fasten it self to the substrate...In this case I would use a flat rock that way if you need to move the clam you can do it safely.We also have a sponsor that has a handy clam cradle to offer. here is the link if you need one.
http://www.nicksacrylicreef.com/Livestock_Accessories.html
Also keep in mind if the byssal threads fasten them self to a large rock and you cant take the rock out you can safely cut them with a razor blade.


Tridacnids have hundreds of eyes along the edges of there mantle. These eyes are used to mostly detect shadows, which warns them of potential predators. There eyes also serves a purpose for the detection of excessive amounts of harmful UV wavelengths.

Smaller clams fulfill there nutritional requirements by filter feeding and absorbing dissolved organic compounds from your aquarium. Basically what you need to do with these little guys is feed them by taking them out of the tank and placing them in a bowl of tank water with ""phytoplankton""
twice a week. You will know when the clam is done eating.. The bowl of phyto will be almost clear.


Older Tridacnids (4 inches+) will make there own food by using there zoozanthellae to manufacture food for themselves.
One important thing that I did not type yet is..
To own one of these guys is your tank must be stable..

NO...NO!!

Ammonia
Nitrate(Low NO4 is O.K but better to have none)
Nitrite
Phosphate

And of course you will need a Calcium test kit, Iodine Test, Kh/Alk test kit, and a Magnesium test kit..

I would suggest Salifert for your test kits too
A must have too...
Your Tank has to be running at least 8 months..

 

[_Eric_]

Now how about we talk about some of the different species of clams out there.

Lets start of with the

Gigas Clam

Scientific name__Tridacna gigas

The Gigas clam is the one the the largest clams kept in reef tanks.
They are also one of the largest clam in the wild as well. There mantle is usually golden brown, yellow, or olive green with tons of iridescent blue or green spots.

There natural environment is from the Indo-Pacific. Water depth of 30-60 feet deep.

The Gigas is a very hardy clam with the right reef tank conditions. They are a fast grower too. They need moderate light as well..
Good clam for a beginner.

 

[_Eric_]

Next clam.

Derasa clam



Scientific name__Tridacna Derasa


The Derasa clam usually have wave-line patterns. The mantle patterns consist of yellow, orange, black, blue, and white...(Keep in mind all clams that I am talking about today have many other color morphs too.)
The Derasa are a very faster grower..Here's an example for ya..
Growing 2" to 5"-6" in only one years time. :shock:
There max growth is a length of 24 inches.

There natural environment is from the Indo-Pacific in shallow waters.


The Derasa is a very hard clam as well. As long as there is moderate light and great tank conditions..
Good clam for a beginner.

 

[_Eric_]

Alright..
Lets talk about the

Squamosa clam



Scientific name__Tridacna Squamosa

The Squamosa clam has a color that is mostly brown with colored spots and wavy lines. I have seen some of them blue, Green and tan. They can get as big as 16".


There natural environment is from the Indo-Pacific and are in 30-50 feet deep waters.

The Squamosa is a hardy clam as well.

The Squamosa does need more light than the previous clams that we have covered though..

Still good for a beginner hobbyist though. :wink:

 

[_Eric_]

Next, one of my favorite clams.

The Maxima clam


Scientific name__Tridacna Maxima

The T maxima clam has a large range of colors and patterns ranging from
brown, green, blue, purple, yellow and green.
There max growth is close to 14".


There natural environment is from the Indo-Pacific and are in shallow waters but have been also found in waters that are 45 feet deep.

They are a hardy clam if all is kept up in the aquarium. They do require intense light..
I would not recommend the T Maxima for a beginner clam..

 

[_Eric_]

Next clam is the!

Crocea clam



Scientific name__Tridacna Crocea


There natural environment is from the Indo-Pacific in shallow waters.

The Crocea is one of the attaractive clams and it is easily confused with the T Maxima clam. There colors patterns range form blue, purple, yellow, brown, gold, and orange. The Crocea is one of the slowest growing clams and one of the most light demanding clams.
There max growth is 6-9".

They are a hardy clam if all is kept up in the aquarium. They do require intense light.. More intense than the Maxima clam.
I would not recomend the T Crocea for a beginner clam..

I hope you learned and enjoyed my article..


Sincerely,
Eric

 

[_Eric_]

Here is an old picture of my Derasa clam.

 

[_Eric_]

Here is a picture of my tear drop Maxima.

 

[_Eric_]

Here is a picture of my Crocea.

 

[_Eric_]

My Ultra Crocea

 

[_Eric_]

 

[Moe_K]

Very nice, Eric, thanks.
Lets keep the thread going, folks.
At least post a picture of your clam and let us know how long you've had it, what type of lights, and how you maintain calcim and carbonate.
If you think of anything else to add, please do so.

 

[nunofs]

Great posts, Eric.

Per Moe's request, here's a pic of my Crocea:

I've had it for 3 months, it sits at the top of my rockwork, under T5 lighting (6x 54W). It's growing well and seems very healthy. Calcium is kept at around 450ppm and alk at around 12dkH.

Nuno

 

[NateHanson]

How do folks mount their clams. And where? Sand or rockwork? What are things to watch for in clam care? Danger signs? Fixes?

 

[Reef55]

How do folks mount their clams. And where? Sand or rockwork? What are things to watch for in clam care? Danger signs? Fixes?

As to how you mount a clam... you don't. It will attach itself to rock via its byssus gland. Multiple thin threadlike things come out of the gland to anchor it in place. Doesn't happen immediately though, so when placing the clam it needs to be in a stable location that allows it to fully open.

For smaller clams that need to be fed phytoplankton, they can be put into a small glass bowl. The clam will attach to the bowl, and when you need to feed, just pull out the bowl, feed, and put back in the tank. This way you aren't disturbing it much and can still spot feed. Another option if it will fit is to cut the bottom off a 2 liter bottle. With the cap off, put it over the clam (if the clam is on your sand). Squirt the phyto down the opening of the bottle, then put the cap on. Leave in place until the water is clear again

Mark

 

[smcnally]

Here's my Derasa. I't's grown about 1" since I got it in February (It's about 6-8 inches now). I dose B-Ionic 2-part, and keep my calcium around 460 / Alk is around 12 dKh right now.