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View Full Version : Dosing amino acids; A good idea?


HighlandReefer
10/10/2009, 12:45 PM
The natural amino acid production inside coral tissues is much higher than I expected. ;)

How might this impact hobbyists who are dosing amino acids? Perhaps dosing amino acids may be excessive?


Net release of dissolved organic matter by the scleractinian coral Acropora pulchra:
http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6T8F-4WW1714-2&_user=10&_rdoc=1&_fmt=&_orig=search&_sort=d&_docanchor=&view=c&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=7419e009329b17f27d7e9354a8dd5831

"The net production of dissolved organic matter (DOM) and dissolved combined and free amino acids (DCAA and DFAA, respectively) by the hermatypic coral Acropora pulchra was measured in the submerged condition, and the production rates were normalized to the coral surface area, tissue biomass, and net photosynthetic rates by zooxanthellae. When normalized to the unit surface area, the production rates of dissolved organic carbon and nitrogen (DOC and DON, respectively) were 37 and 4.4 nmol cm− 2 h− 1, respectively. Comparing with the photosynthetic rate by zooxanthellae, which was measured by 13C-tracer accumulation in the soft tissue of the coral colony, the release rate of DOC corresponded to 5.4% of the daily net photosynthetic production. The tissue biomass of the coral colony was 178 µmol C cm− 2 and 23 µmol N cm− 2, indicating that the release of DOC and DON accounted for 0.021% h− 1 and 0.019% h− 1 of the tissue C and N, respectively. The C:N ratios of the released DOM (average 8.4) were not significantly different from those of the soft tissue of the coral colonies (average 7.7). While DFAA did almost not accumulate in the incubated seawater, DCAA was considerably released by the coral colonies at the rate of 2.1 nmol cm− 2 h− 1 on average. Calculating C and N contents of the hydrolyzable DCAA, it was revealed that about 20% and 50%–60% of the released bulk DOC and DON, respectively, were composed of DCAA."

Randy Holmes-Farley
10/10/2009, 02:12 PM
Even if total amino acids are released, certain ones may still be deficient. For example, aspartic acid. :)

That said, I've not bothered to dose them. :)

HighlandReefer
10/10/2009, 03:03 PM
Thanks for the input Randy. You made me did deeper into the subject. ;)

It appears from this paper that production of aspartic acid is not a problem for well fed coral, at least during lighted periods.

Interactions between zooplankton feeding, photosynthesis and skeletal growth in the scleractinian coral Stylophora pistillata
http://jeb.biologists.org/cgi/reprint/207/9/1461.pdf

"We investigated the effect of zooplankton feeding on
tissue and skeletal growth of the scleractinian coral
Stylophora pistillata. Microcolonies were divided into two
groups: starved corals (SC), which were not fed during the
experiment, and fed corals (FC), which were abundantly
fed with Artemia salina nauplii and freshly collected
zooplankton. Changes in tissue growth, photosynthesis
and calcification rates were measured after 3 and 8 weeks
of incubation. Calcification is the deposition of both an
organic matrix and a calcium carbonate layer, so we
measured the effect of feeding on both these parameters,
using incorporation of 14C-aspartic acid and 45Ca,
respectively. Aspartic acid is one of the major components
of the organic matrix in scleractinian corals. For both
sampling times, protein concentrations were twice as high
in FC than in SC (0.73 vs 0.42·mg·P–1·cm–2·skeleton) and
chlorophyll c2 concentrations were 3–4 times higher in fed
corals (2.1±0.3·mg·cm–2). Cell specific density (CSD), which
corresponds to the number of algal cells inside a host cell,
was also significantly higher in FC (1.416±0.028) than in
SC (1.316±0.015). Fed corals therefore displayed a higher
rate of photosynthesis per unit area (Pg
max=
570±60·nmol·O2·cm–2·h–1 and Ik=403±27·mmol·photons
m–2·s–1). After 8 weeks, both light and dark calcification
rates were twofold greater in FC (3323±508 and
416±58·nmol·Ca2+·2·h–1·g–1·dry·skeletal·mass) compared
to SC (1560±217 and 225±35·nmol·Ca2+·2·h–1·g–1
dry·skeletal·mass, respectively, under light and dark
conditions). Aspartic acid incorporation rates were also
significantly higher in FC (10.44±0.69 and 1.36±
0.26%RAV·2·h–1·g–1·dry·skeletal·mass, where RAV is total
radioactivity initially present in the external medium)
than in SC (6.51±0.45 and 0.44±0.02%RAV·2·h–1·g–1
dry·skeletal·mass under dark and light conditions,
respectively). Rates of dark aspartic acid incorporation
were lower than the rates measured in the light. Our
results suggest that the increase in the rates of calcification
in fed corals might be induced by a feeding-stimulation of
organic matrix synthesis."