Golden pearls, DT's, Marine Snow....why?

[golfish]

Just wondering if you guys feel this stuff is needed for the larger clams. I see lots of you guys use it. Do you really think your clams need it?

I have never noticed a difference when using these kinds of foods in my clams or my SPS.

[Hippopus]

Golfish,
Yes! I use Dts to the "maxima" level! This was reinforced afew weeks ago. As I was taken down one of my clam tanks (a 120 gallon) I have a new larger one. With a friend I started removing some liverock. After removing afew big pieces we noticed a maxima clam shell about 3 inches is size, he was siiting on his side. Now this clam must after fallen off his perch several months ago. When I picked him up he was still ALIVE! Now this maxima had not gotten any light for many months! The only reason he is alive and doing well today is because were he fell was the exact spot I pour the DTs into the tank! So yes I have clams from 2 inches to over 16 inches and all filter DTs!
Jim

[scubadude]

I have been going through a similar question in my head lately and its been the battle of Live Foods versus Enhanced Foods such as flake frozen etc etc and I have come to the conclusion that a mixture of both is probably the spice of life, the trick is knowing when to feed what and I personally try and alternate as much as possible. I have found that if I stick to feeding the same food over and over then certain areas seem to decline, I also thought of the frozen mixture slurrys of food like Mr. Borneman has a nice recipe in his book for which consist of a very large variety of foods mixed into one, but I just cant shake the idea of feeding my tank just one source over and over again. I do feed Golden Pearls, and I do feed live phyto plankton....havent used marine snow yet but would if I had it ....or atleast I would try it.

[Barry N.]

Mark,

I also use DT's in my main clam tank but have a few small tanks set up as a few companies have asked that I try their product so we are doing some testing with 3 products.

Been using Dt's for over a year and I surely like it. Dr Ron Shimek has writen some great artical regarding feeding of Giant Clams and after keeping Giant Clams for many years I have to agree with what he says. Clams of all sizes need food as they have a digestive system so that means they can not just live off photosynthesis.

Dr. Ron Shimmek:

Many aquarists have had the experience of keeping Tridacna alive for a few months after which they mysterriously die, after seemingly" doing well." Well...they haven't done well, they have slowly starved to death using up all their energy reserves and finally dying. All of these deaths - ALL OF THEM-could have been prevented by adequate feeding with good phytoplankton

With all due respect, I wouldn't say All OF THEM but a very large percent of them.

Barry

[traveller7]

Barry,

While certainly subjective at an early stage, are they any interim results for the other foods you are playing with? I am about out of the DT's and was thinking buying a smaller batch of DT's and something else.

traveller7

[Barry N.]

Am currently trying some other phytoplakton food in seperate tanks so I can see if there is a differents in the clams.

One product that I am using with the DT's is KORALvit F which has yeast and vitamin B in it and if you have read Daniel's book he stated that is one food that clams love. I have been using it for a few weeks and the clams appear to really extend more so then when I was just using the DT's I think it is a VERY good suppliment to feed. I have other Knop product but haven't really had time to try them.

Hope this helps.

Barry

[hreef]

Hi Barry, I too have been experimenting with different types of phyto-liquid foods. I really like DT's. I liquidfy with RO water, spirlina flakes along with Golden Pearls. I dose 3 times a week, about a tsp at night. I do not make but just a cup full at a time and refrigerate. I found as long as you are feeding the tank, they should not be deprived of what they filter. I use kents phytoplex , I use the "dead" stuff as a supplement. I dose Zoe too, it has vitamin b and essential lipids and other vitamins. Good Luck, I too wonder if my clams are getting enough food. I just try to keep a routine going with feeding.
Holly

[Barry N.]

Hi Holly,

Nice to see you here;) So many people think that they do not have to feed their clams as they will live off photosynthesis alone, not true they have a digestive system which means that have to eat.

Barry

[butesch]

Just reading up on clams and I see your post that says they need supplemental feeding.

Yet on the care page of the clams direct website it says they need no special feeding?

I am hoping to get into clams.........please tell me which is correct?

Thanks.

[Barry N.]

butesch,

Thanks for bring that to my attention as that link was made a year ago and since then, I have changed my views on that. Small clams do need feeding but since I have been doing some testing with different feeding products, I now find that clams seem to do better when fed.

I will change that link this coming week.

Thanks and welcome to ReefLand.

Regards,

Barry

[Ninong]

Barry,

I would be inclined to agree with your original statement that clams need no special feeding provided you are referring to adult clams and provided that people do not ignore the fact that you have included the adjective "special" before the word "feeding."

All of the scientific articles that I have read on the anatomy of giant clams that have been published by people who specialize in this field state that giant clams get a significant percentage of their nutrition from filter feeding as juveniles but that as they mature they switch to almost exclusive dependence on their zoozanthellate photosynthesis. They can still, to a certain extent, filter phytoplankton from the water and then utilize that as food but the photosynthetic products of their zooxanthellae make up >90% of their energy uptake. Some authors state that in most cases symbiotic algae provide all of the required energy (Fisher et al., 1985). In fact, in most species, the organs for food intake show signs of degeneration, which is an indicator of their dependence on symbiotic algae.

It is important to remember that giant clams can and do absorb dissolved organic compounds directly from the water via their mantle (Goreau et al., 1973). Even though you may see references in Knop and elsewhere that state that adult giant clams meet 90-95% of their energy requirements from zooxanthellate photosynthesis, that doesn't imply that the remaining 5-10% must come from filter feeding. Just like many corals, giant clams get a significant amount of nutrition directly from the water via absorption. Which is why I would tend to agree with your original statement that adult clams do not require special feeding. This is based on the assumption that the clams will be housed in a reeftank with corals and fish that will be fed on a regular basis.

This is not to say that it is a bad idea to feed phytoplankton to your clams (it is even essential when they are small), only that it is probably unnecessary to feed them anything special after they are mature. Assuming that everyone will want to err on the safe side and feed their clams anyway, regardless of their size, there are some things that they should keep in mind in choosing the special food that they offer them. First, they really cannot filter microalgae greater than 15 microns in size and, second, the microalgae that you choose may be deficient in the required nutritional elements. The microalgae that is available on the market is available because it is a commercially viable product that is easy to cultivate, etc. You may be interested to learn that Nannochloropsis spp. are primarily used for enriching zooplankton to feed fish larvae in fish hatcheries; it is not used in commercial bivalve cultivation, at least not in Australia. In Australia the most popular species for bivalve cultivation are Isochrysis sp. (T.ISO), P. lutheri, C. calcitrans and C. muelleri. For the prawn industry, C. muelleri is the most popular.

Some people might argue that because clams have digestive organs they must ipso facto be fed. This would seem logical, especially based on our knowledge of corals. But there are significant differences in the anatomy of corals and giant clams beginning with the location of their symbiotic algae. Zooxanthellae live inside endodermal cells in corals but in giant clams they establish themselves in the ectoderm, the outermost cell layer. And there are higher concentrations of zooxanthellae in giant clam mantles than in corals. Giant clam larvae must capture their zooxanthellae by feeding on phytoplankton (phagocytosis). The free swimming flagellates are filtered out of the water and can survive digestion inside the stomach. Observations in commercial clam hatcheries have shown that metamorphosis from larva to sessile clam can began as soon as a few hours after fertilization or be delayed for a week if conditions are unfavorable. Shortly after metamorphosis one can see algal cells spreading out over the mantle (Fitt & Trench, 1981). Juvenile clams collect free living zooxanthellae and accumulate these in the tissue surrounding both mantle openings (Knop, 1996).

I think that adult giant clams are less dependent on feeding than corals but that they are still capable of filtering phytoplankton in the appropriate size range (1 to 15 microns). Daniel Knop has found that they are fond of yeast, so products that contain yeast may enhance growth, but I still think that in their natural environment mature giant clams get less than 5% of their nutrition from filter feeding and can, in fact, meet their minimum nutritional requirements through absorption and photosynthesis alone.

P.S. -- Maybe I should have included the caveat that adequate photosynthesis requires adequate lighting. According to Knop, minimum lighting for Tridacna spp. is 250w metal halide.

[Hippopus]

Ninong,
Great reply! My concern is at what age does a clam mature? On a maxima most state anything around 3 to 4 inches is mature. But clam farms state about 8 inches is when a maxima is mature. So if one is feeding their clams and stops feeding altogether to soon what happens???? Your right on with DT's formual. But it has been the best food out there so far. Reed maricluture, Inc. has developed a food for clams and sps that I have been trying and it is good! It contains 5 strains were DT's contains one. It will be available to the public soon!
Jim

[Ninong]

Jim,

I think that a safe size for T. maxima would be >4". What I mean by that is that at that size it no longer really requires special feeding. It may not be fully mature, but it can get by in a reeftank without special efforts specifically aimed at it.

The type of product that you are trying right now from Reed Mariculture, Inc. would be a step up compared to what is presently available. DT's is excellent, but it is not ideal.

[Hippopus]

Yes,
The product is DT's to the next level. And the price is way less!
Jim

[Captain Clam]

When can we get some?

[Barry N.]

Ninong,

Great post and thanks for sharing that great information.

Have read the articals as well and most have been written some years ago. With the awareness of keeping Tridacnid Clams has grown these past few years and some other research has been going on at the farms and also with some hobbyist, I think it has opened up some new avenues that we should also consider. No doubt that a tank will do better for the animals if it is well established and has lots nutrients
in the water.

Daniel Knop

It is a widespread misconception that clams live solely on their symbiotic algae. The presence of a fully developed intestinal tract with a digestive tract with digestive glands, bowels,and anal papilla as described in the chapter on anatomy speaks for the contary.

I think that is what you made reference too.

If a tank has a large fish load and the hobbyist is feeding the fish well, then there in no doubt that there is a large amount of so-called nanoplankton available.

I have been suppliment feeding with a product that is yeast based and it appears that the clams except it very well as far as fully extending it's mantles. As far as tracking growth rate, that is a slow process as we all know.

As far as symbiotic algae living in the siphonal mantles of the clams, the density per square unit is about 10 times in comparison to corals and produces a high degree of photosynthesis. Nitrogen now comes into play. A small number of clams being kept, the amount of nitrogen utilized is not probably negligible but larger numbers of clams being kept will lead to nitrogen deficiency. Another good paper wrote on this subject is (C.A. Belda 1993)

I feel that most of the cultured clams sold are in the size range of 1.5" - 3.5" that is one reason I think feeding is important at that size range. The more clams you have in a tank the more compititive for food source.

The farms are doing so much more then they did a few years ago, such as some are using ammonia nitrates for growth. Have heard of some other things that are being tried at this time and I think we should keep our options opened and continue to share idea's as I am sure there is so much that we need to learn about these amazing creatures.

Truly love reading post and threads like these as it is good for all to share. These boards can be a teaching and learning experence for all.

Barry

[Hippopus]

Should be availiable this week!
The five main cultures are:
nannochloropsis
isochrysis (T-iso)
tetraselmis
pavlova thalassiosira pseudonana (3H)
thalassiosira weissflogii (TW)
Like DTs it needs to be refrigerate. It is also concentrate.
Example my main show tank with refugium is about 300 gallons. I use the max DTs of 120 ml every other day. With this new product I use 10ml every other day. A 30 oz. bottle of DTs is about equal to 100ml of this product and I think it is approx going to be $20.00 less!!!!!!
Jim

[Ninong]

Barry,

You can get a lot of information from some of the Australian websites, such as the Australian Institute of Marine Science: http://www.aims.gov.au/index-ie2.html This is an enormous site with tons of information on studies done on the Great Barrier Reef as well as information developed through their various workshops. They have tested hundreds of species of microalgae and have found that about 20 species meet their requirements as far as being available locally, being easy to cultivate and having valuable nutritional elements. Check out their Hatchery Feeds Workshop: http://216.239.53.100/custom?q=cache...rt=27&ie=UTF-8

Another interesting site is: http://www.mesa.edu.au/friends/seashores/page1.html

[Barry N.]

Thanks SO MUCH!

Barry

[Captain Clam]

Barry and/or Jim - Please be sure to make a post when any of these products become available. Any comments you may have from testing them out would also be greatly appreciated. Thanks.