Clam food

bknapp · Jan 27, 2015

I love spot feeding my corals and watching as they eat. I've recently got my first clam, an ORA Derasa. And I was wondering if there were any good foods for clams.

Thanks guys.

Tahoe61 · Jan 27, 2015

I know some individuals feed their smaller clams phytoplankton, brand I have no idea. Personally any clam larger then 2 inches does not need/require feedings if you're providing adequate lighting.

skinz78 · Jan 27, 2015

https://www.reef2reef.com/forums/cl...on-pyramidellid-snail-removal.html#post634767

hart24601 · Jan 27, 2015

A few years ago the conventional state of mind was that you had to feed small clams phytoplankton and not large ones after they grew beyond 2-3â€. Now the assessment seems to be that they do not require any additional feeding aside from strong lighting.Now obviously there are many people who have kept clams with no feeding, but that doesn't mean there is no benefit to growth or more importantly, acclimation to a new system after shipping (1-2 months).

The champion of the no extra feeding seems to be James Fatherree â€“ well sort of. He says in most systems they donâ€™t need feeding as they get fed from nitrogenous byproducts. I think that last point has been lost on many people.

Aquarium Invertebrates: Tridacnid Clams (Usually) Don't Need to Be Fed in Aquaria ? Advanced Aquarist | Aquarist Magazine and Blog

This study shows how fast giant clams can uptake ammonia and phosphate and that occur, but only under optimal lighting which agrees with commercial propagation as they drip ammonia into the water to speed growth. They also indicate nutrient rich water is more efficient than algae feeding, but I donâ€™t see good data analysis in that paper.

http://www.nova.edu/ncri/11icrs/pro...m10-07.pdf

Another paper indicating that while some clams can get energy needs solely from zooxanthellae filter feeding does play a part and is important in deeper water dwelling species.

http://www.int-res.com/articles/mep...07p147.pdf

I do wonder with the current popularity of ultra-low nutrient systems with bioplastics and incredible skimming systems ****** clam growth or increase mortality, but I am sure there are many that have kept clams in those systems with good results but the two studies below indicate that N and P (N much more so) are critical to juvenile clams and without they are nutrient limited.

http://www.int-res.com/articles/mep...70p131.pdf
http://isjd.pdii.lipi.go.id/admin/j...127130.pdf

Interesting article about hard clams and their total reliance on feeding most interesting is that they use commercial products:

http://somas.stonybrook.edu/~MADL/p...growth.pdf

Yet another showing how important early symbiosis is for even the larvae, while still needing phytoplankton.

http://www.scielo.br/scielo.php?pid...ci_arttext

Anyway, while feeding does not appear needed unless maintained in an ultra low nutrient system, it does look to be beneficial in my opinion if the addition of food is not overdosed. I think there is value in feeding phytoplankton after shipping and during acclimation (based off a few decent studies I think DTâ€™s is the best brand) and there may be some value in feeding artificial food of the correct size, such as the smallest size golden pearls.

MondoBongo · Feb 4, 2015

there is no need to feed Tridacna clams, it provides them nothing. their primary method of carbon supply is from their symbiodinium. it is a common myth, for some unknown reason, that they need fed. this is not supported by any of the current scientific literature.

hart24601 · Feb 4, 2015

MondoBongo said:
there is no need to feed Tridacna clams, it provides them nothing. their primary method of carbon supply is from their symbiodinium. it is a common myth, for some unknown reason, that they need fed. this is not supported by any of the current scientific literature.

While there is no need to feed, I don't think one can say it provides nothing. They do feed and digest food, and while not required, there is no evidence to say filter feeding does nothing to benefit the clam. Just like how they don't require elevated nitrogen, but grow much faster with it. All that info is in the papers above.

MondoBongo · Feb 4, 2015

there is quite a substantial amount of evidence that it is a neutral if anything, and will provide no benefit to the clam up to and beyond the point that the other needs of it have been met. the vast majority of the nutrients the clam takes in are directly through adsorption, not filter feeding.

MondoBongo · Feb 4, 2015

Aquarium Invertebrates: Tridacnid Clams (Usually) Don't Need to Be Fed in Aquaria ? Advanced Aquarist | Aquarist Magazine and Blog

However, it is important to note that no matter how much a tridacnid eats, it still needs bright light and apparently cannot make up for a lack of light with more feeding. Tridacnids are never found in dim/dark waters, regardless of the availability of planktonic/particulate foods, and I tried feeding a couple of them copious amounts of phytoplankton in a low-light aquarium with no luck, either. They eventually had to be removed to save them.

When it comes to absorbing nutrients, tridacnids can take them directly from seawater via the use of a specialized tissue that covers their surfaces (Fankboner 1971, Goreau et al. 1973, Wilkerson & Trench 1986, Fitt et al. 1993, Belda & Yellowlees 1995, Hawkins & Klumpp 1995, and Ambariyanto & Hoegh-Guldberg 1999).

Thus, any notion that their sole means of acquiring nitrogen, phosphorus, etc. is through filter-feeding is incorrect, as nitrogen and phosphorus are primarily taken directly from the surrounding seawater in forms other than plankton or detrital particles.

Nutrition of the giant clam Tridacna gigas (L.) I. Contribution of filter feeding and photosynthates to respiration and growth

We conclude that autotrophy is the major source of carbon to this clam, potentially capable of satisfying all respiratory requirements of the host.

www.nova.edu/ncri/11icrs/proceedings/files/m10-07.pdf

Although recent research into ecological and physiological background of different stages of the life cycle of clams made commercial aquaculture possible, there is still a high mortality with early stages. While juveniles rely on both heterotrophic and
autotrophic feeding, adult clams depend more on available light.

Results show that light intensity and spectra have a significant effect on survival and length or weight increase. Nutrient concentrations only seem to play a role when clams are kept in optimum light conditions. In this case fertilization with NH4+ and PO43- is more effective than feeding with algae.

hart24601 · Feb 4, 2015

MondoBongo said:
there is quite a substantial amount of evidence that it is a neutral if anything, and will provide no benefit to the clam up to and beyond the point that the other needs of it have been met. the vast majority of the nutrients the clam takes in are directly through adsorption, not filter feeding.

Can you link those studies please? I keep bookmarks on clam studies and I don't remember seeing those - well I have been plenty about adsorption as I already linked.

Gigas sure uses filter feeding (but it's the most studied): Nutrition of the giant clam Tridacna gigas (L.) I. Contribution of filter feeding and photosynthates to respiration and growth

This indicates that while derasa and tevoroa are not as dependent on filter feeding they still use it 8-14% when avaliable. http://www.int-res.com/articles/meps/107/m107p147.pdf

While not the best this indicates squamosa uses heterotrophy, but not maxima, to extend its range: Photosynthetic performance of giant clams, Tridacna maxima and T. squamosa, Red Sea - Springer

KorD · Feb 4, 2015

I fed mine phytoplankton.

MondoBongo · Feb 4, 2015

linked above.

thank you for the links, i'll check these out.

hart24601 · Feb 4, 2015

Don't get me wrong, not arguing, I am pretty interesting in giant clam research so just trying to get more info.

I agree 100% that they don't need to be fed in proper conditions, and they utilize dissolved nutrients more effectively, but in those articles you linked they didn't say the clam does not benefit from filter feeding after the light requirements have been met. Just that it isn't required, which I why I stated that there is no evidence that filter feeding does not benefit the clam. Not based off any paper, but I personally feel that feeding could help in times of stress such as after shipping or in acclimation before the clam is comfortable fully extending the mantle.

MondoBongo · Feb 5, 2015

hart24601 said:
Don't get me wrong, not arguing, I am pretty interesting in giant clam research so just trying to get more info.

I agree 100% that they don't need to be fed in proper conditions, and they utilize dissolved nutrients more effectively, but in those articles you linked they didn't say the clam does not benefit from filter feeding after the light requirements have been met. Just that it isn't required, which I why I stated that there is no evidence that filter feeding does not benefit the clam. Not based off any paper, but I personally feel that feeding could help in times of stress such as after shipping or in acclimation before the clam is comfortable fully extending the mantle.

no totally, i love talking about this stuff, and if my information is incorrect, or i'm drawing the wrong conclusion then i prefer to find out what the right answer is. in the end it all leads to better husbandry.

i feel the opposite about the feeding during times of stress. if they're not benefiting from filter feeding feeding until their lights needs are being met, and they're stressed or retracted and not able to photosynthesize, then it seems like wasted effort.

i was actually thinking about this yesterday on the drive home a bit, and i was wondering if the perceived benefits of filter feeding might have to do with the fact that the decaying phyto matter could provide the clams with some nitrogen and phosphorus in otherwise nutrient poor systems?

it also makes sense that this would vary from species to species.

one of the really frustrating things about all of this for me has been the academic pay wall. it is tough to find information on reef inhabitants in general, and often when i do they want upwards of $30 per paper. as a hobbyist, it' s just not practical for me to go around spending hundreds of dollars on research papers.

mainly the third paper seems to have the best information (Physiological performance of giant clams (Tridacna spec.) in a recirculation system).

Results show that light intensity and spectra have a significant effect on survival and length or weight increase. Nutrient concentrations only seem to play a role when clams are kept in optimum light conditions. In this case fertilization with NH4 + and PO4 3- is more effective than feeding with algae.

hart24601 · Feb 6, 2015

I forgot about the pay articles... I am lucky to use my work account and DuPont already has subscriptions to lots of journals and it's all automatic.

Interesting idea about feeding could elevate nutrient levels, sadly for us, there just isn't a whole lot of in depth research on this particular subject. I am happy to agree to disagree on this subject though, lol, I think the information is sparse enough that one could draw either conclusion from the literature. I still think providing food can possibly help clams, and if not taken overboard, sure doesn't hurt. It does seem to provide greater benefit to different species - but considering all the types of planktonic food, natural and artificial, coupled with variation in clam species and perhaps even individual differences, I doubt there will be a definitive answer in my lifetime at least!