Tridacna Clams and feeding/care

Hey all, I was wonder what is your feeling about feeding clams? I know 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 2-3”. 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 I am curious what people think about feeding for extra 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 – well sort of. He says in most systems they don’t need feeding as they get fed from nitrogenous byproducts. I think that last point has been lost on many people.

http://www.advancedaquarist.com/2010/7/inverts

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 don’t see good data analysis in that paper.

http://www.nova.edu/ncri/11icrs/proceedings/files/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/meps/107/m107p147.pdf

I do wonder with the current popularity of ultra-low nutrient systems with bioplastics and incredible skimming systems retard 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/meps/170/m170p131.pdf

http://isjd.pdii.lipi.go.id/admin/jurnal/12207127130.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/pubspdf/Emma-clamgrowth.pdf

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

http://www.scielo.br/scielo.php?pid=S1679-87592012000200003&script=sci_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 DT’s is the best brand). I recently bought a crocea and am dosing DT’s but at a much lower rate than the bottle suggests. I will discontinue if I notice increased algae growth, and will probably not dose after the 1[sup]st[/sup] few months as I have P and N in my system to sustain him.

So does anyone else see value in phytoplankton with their clams or am I way out of line? I have not really seen anyone talk about longer term acclimation and feeding to reduce mortality. Thoughts?

 

Silly me! I forgot the most important one. I have a copy of the paper if anyone can't access it.

http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=8567206

From the paper: "Among clams cultured with and without supplemental phytoplankton (Chaetoceros spp.), feeding resulted in significantly lower mortality in all species but T. deresa, whereas growth was significantly higher among fed clams for all species except T. squamosa."

From what I understand the water used in the growth aspect was not N rich, but I think this paper does have impact on keeping these clams.

 

Anyone?

Bueller?