Coral Scientists Learn from Aquarists

[PeterIMA]

Subj: Re: [Coral-List] coral bleaching: response to Goreau
Date: 6/1/2006 8:26:51 AM Eastern Standard Time
From: [email protected]
To: [email protected], [email protected]
CC: [email protected], [email protected]
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Dear Tom and Margie,
As someone who sits on both sides of the fence (research and aquarium keeping) the information and knowledge know on both sides is interesting/varied and not well communicated. Yes many aquarium owners in the begin know little about feeding corals, however with the high cost of purchasing each piece the last thing you want (and can afford) is for the coral to die. When I was in working in the aquarium trade I instructed/taught each customer how to feed the coral they had bought. I know of a number of shops (In Australia) that sell "green water" (marine algae cultures) and rotifer/green water mixes by the litre as well as a number of commercial products for feeding coral and inverts (that in some case won't be removed by protein skimming well that is what the bottle said). For the case of large corals Euphyllia's, cataphyllia's and favities/favia hand feeding is done, placing small pieces of fish/prawn/octopus onto the tentacles. I did get some strange looks from customer when
I explained what to do, however this was normally replaced by questions on their next visit like "what else can I feed my corals? we sat there for hours watching the coral eat the food! and what corals eat what food?"

As to how we share or learn from each other can be as simple as a researcher joining an aquarium club. A number have host nights where they all gather at a members house or at an aquarium shop and discuss new filtration ideas, refuge tanks being one of interest in Australia for the last few years, to natural condensed light vs 250 watt 20,000 kelvin metal halides vs fluoros as well as swapping coral fragments harvested from their home aquariums. Another possibility is publishing journals in aquarium magazines. With the advent of googling and scholar google some of the questions being raised by hobbists are highly technical. A copy of Charlie Verons "corals of the world" are a must for the serious aquarium keeper as are a number of the more technical marine biology reference books. As is identifying corals to the species level and learning how to propagate them.

Hope this helps and not raises more issues/questions


Dion

 

[PeterIMA]

Subj: [Coral-List] Coral feeding
Date: 6/1/2006 1:19:14 PM Eastern Standard Time
From: [email protected]
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Dear Coral-listers:

There has been quite a bit of discussion about
what corals eat, how much they eat, and what some
of the downstream effects of feeding are. I
would like to point you to a few publications
from my group involving corals studied in situ on
the reef. We have found that coral feeding rate
varies among species, with depth, with
zooplankton abundance, and with
bleaching. However, what they eat is always the
same. We have also found that of all six species
of corals we have examined, at all depths and
health status, that they all eat zooplankton
predominantly in the 200-400 micron size class,
and that their diet consists primarily of crab
zoea, amphipods, and isopods or shrimp (corals
studied include: Montipora capitata in Hawaii,
Porites compressa in Hawaii, Porites lobata in
Hawaii, Pavona clavus in the Gulf of Panama, and
Pavona gigantea in the Gulf of Panama, and
Pocillopora damicornis in the Gulf of
Panama). Other work by Ken Sebens group has
shown the effect of flow on feeding and that
tentacle structure affects zooplankton capture
capability. Others have also shown that bacteria
and/or particles can make up a measurable amount
of fixed carbon in the diet. In addition, my
group has natural abundance isotopic evidence
that both photosynthetically and
heterotrophically acquired fixed carbon is
incorporated into the coral (this is from a
combination of field and tank studies). Our
research strongly supports the idea that corals
are both photoautotrophic and
heterotrophic. What is emerging however, is that
the relative proportion of fixed carbon acquired
via one mechanism or the other, varies among
species, and with bleaching vs. healthy
status. In other words, there is no single
formula that would apply to all corals, but
rather a several alternative photo vs hetero
combinations that can vary with bleaching. I
have included a list of references here for those who might be interested.

Sincerely,
Andrea Grottoli

Published papers;
1- Grottoli AG, Rodrigues LJ, Palardy JE. (2006)
Heterotrophic Plasticity and Resilience in
Bleached Corals. Nature 440: 1186-1189 doi:10.1038/nature04565
2- Palardy JE, Grottoli AG, Matthews KA. (2006)
Effect of naturally changing zooplankton
concentrations on feeding rates of two coral
species in the Eastern Pacific. Journal of
Experimental Marine Biology and Ecology, 331(1):99-107
3- Palardy JE, Grottoli AG, Matthews K (2005) The
effect of temperature, depth, morphology, and
polyp size on feeding in three species of
Panamanian corals. Marine Ecology Progress Series 300:79-89
4- Rodrigues LJ, Grottoli AG (in press)
Calcification rate and the stable carbon, oxygen,
and nitrogen isotopes in the skeleton, host
tissue, and zooxanthellae of bleached and
recovering Hawaiian corals. Geochimica et
CosmochimicaGrottoli AG, Rodrigues LJ, Juarez C
(2004) Lipids and stable carbon isotopes in two
species of Hawaiian corals, Porites compressa and
Montipora verrucosa, following a bleaching event. Marine Biology 145: 621-631
5- Grottoli AG (2002) Effect of light and brine
shrimp levels on the skeletal d13C values of the
Hawaiian coral Porites compressa: a tank
experiment. Geochimica et Cosmochimica Acta 66: 1955-1967
6- Grottoli AG (1999) Variability in stable
isotopes and maximum linear skeletal extension in
reef corals in Kaneohe Bay, Hawaii. Marine Biology 135:437-449
7- Grottoli AG, Wellington GM (1999) Effects of
light and zooplankton on skeletal d13C values in
the Eastern Pacific corals Pavona clavus and P. gigantea. Coral Reefs 18:29-41

other related papers in preps include:
1- Palardy, JE, Rodrigues, LJ, Grottoli, AG. (in
prep) Feeding behavior changes with the loss of
facilitative interactions on coral reefs.
2- Rodrigues LJ, Grottoli AG (in prep) Energy
reserves and metabolism in bleached and
recovering Porites compressa and Montipora capitata corals from Hawaii.
3- Rodrigues LJ, Grottoli AG, Lesser MP (in prep)
Long-term changes in the chlorophyll fluorescence
of bleached and recovering corals from Hawaii.


*******************************************************
Andréa G. Grottoli, Assistant Professor
Ohio State University
Department of Geological Sciences
125 South Oval Mall
Columbus, OH 43210-1398
office: 614-292-5782
lab: 614-292-7415
fax: 614-292-7688
email: [email protected]
web: www.geology.ohio-state.edu/~grottoli
Office location: 329 Mendenhall Labs

 

[PeterIMA]

Subj: Re: [Coral-List] Coral feeding
Date: 6/1/2006 3:27:50 PM Eastern Standard Time
From: [email protected]
To: [email protected], [email protected]
CC: [email protected], [email protected]
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Dear Andrea,

When you say; "into the coral" are you saying that this translocated photosynthate in the form of carbon is going directly into the host issues and not to mucus bi-products? Or are you saying that the translocasted photosynthate or carbon that goes directly to the mucus (which we know is substantial) is part of the "into the coral quote" ? Because If you are saying that the mucus products that are the result of translocated photosynthate defines corals as autotrophic then this is incorrect, because none of this material is going towards the energy buget thus making them heterotrophic. Much of the oxygen is lost into the water-column.

Davy and Cook have also shown that During thermal bleaching host release factors or HRF diverts surplus carbon away from storage compounds to translocated compounds such as glycerol which is found in mucus and within host tissues.

Cheers, James





I believe in compulsory cannibalism.
If people were forced to eat what they killed,
there would be no more wars.
Abbie Hoffman
_______________________________

 

[PeterIMA]

Subj: Re: [Coral-List] [SPAM] Re: coral bleaching: response to Goreau
Date: 6/1/2006 8:04:48 PM Eastern Standard Time
From: [email protected]
To: [email protected]
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There are a couple of points in this discussion that I feel the need
to address:

1) Shops selling phytoplankton as coral food - most research that I
have read involving feeding in stony corals deals mainly with the
ingestion of ZOOplankton. Soft corals, particularly azooxanthellate
ones such as Dendronephthya have been shown to feed on phytoplankton.
This makes sense to me since most of these corals lack nematocysts
and their polyp structures appear to be more suited for sieving food
from passing water than stinging and capturing it as can be seen in
stony corals which all seem to have nematocysts ... why sting a
phytoplankton cell to capture it which is basically a passive entity
unlike a struggling copepod?

I have a pet theory that people who report responses from corals when
fed phytoplankton could be seeing the result of any number of factors
such as the addition of nutrients, the decay of phytoplankton leading
to increased nitrogen and phosphorous levels, to the increase in
filter feeders and hence, an increase in reproduction of these i.e.
more zooplankton being generated.

2) Feeding vs. non-feeding of corals in captivity - yes corals will
feed on zooplankton and more meaty food in the case of corals with
polyps large enough to take them. No one disputes this. What is in
question is do corals in captivity need this? Given that nitrogen,
phosphorous and organic nutrient levels are generally several times
that found on natural reefs is this enough to keep the corals
"happy"? The success of aquarists in Europe with stony and soft
corals in the 1970s and 1980s, without any feeding, would tend to
support this idea.

3) The role of dissolved nutrients - The Waikiki Aquarium has been
keeping, propagating and spawning stony corals, mainly Acropora,
Montipora etc since the late 1970s. We have never added any sort of
zooplankton or phytoplankton to our systems. We use a saltwater well
as a water source for the majority of our exhibit and they are
semi-open systems. The well is 80ft down in coral rock, the chemistry
of this water has been discussed in Atkinson et al. 1995, there is no
zooplankton or phytoplankton in this water. That is not to say that
there isn't any bacteria in the water, or that there could be
plankton being generated in the systems themselves. All I can say
with absolute certainty is that WE do not feed the corals. Yet, we
have observed the release of eggs, sperm and egg/sperm bundles in
corals such as Acropora, Sandalolitha, Montipora, Euphyllia and
Goniopora. What our water IS rich in is nitrogen, phoshporous, iron,
managense, carbon dioxide etc. ... so my feeling is that the
zooxanthellae and perhaps the coral tissue itself, is getting more
than enough of what they need from the water.

4) Increasing contact with the aquarium community - there is an
annual conference in North America called The Marine Aquarium
Conference of North America (MACNA), this year it will be held the
weekend of Sept 23rd in Houston, Texas. This annual conference is the
best place to meet with and observe what hobbyists are doing. There
have been several marine scientists who have spoken at this
conference such as Giselle Mueller-Parker, Daphne Fautin, Marlin
Atkinson, Charlie Veron, Robert Myers, Bob Richmond, Cindy Hunter ...
to name just a few. While there is some contact with hobbyists by the
scientific community there is certainly room for much more. I think
this sort of interaction will only increase for the simple fact that
many of the up and coming marine scientists today have started off by
keeping reef tanks as a hobby, and I am in fact seeing this already.
There are of course other such conferences in Europe held in Germany,
France, Belgium and The Netherlands. Next April there will be a
conference in The Netherlands dealing specifically with the captive
husbandry of corals in public aquariums, of which I am a member of
the steering committee ... we would dearly love to have a strong
representation from the scientific community especially in the field
of coral nutrition, effects of UV, coral colouration, coral
reproduction, etc etc. The days of marine scientists claiming it was
impossible to keep live coral while hobbyists in Europe and elsewhere
were already doing so, are thankfully behind us for the most part.


Finally, I think one needs to be cautious about making sweeping
generalizations about what corals need or don't need in terms of
feeding when it is becoming increasingly obvious that the corals have
various abilities to gather, use and process sources of nutrition
spread across the genera.

Aloha!


J. Charles Delbeek M.Sc.

Aquarium Biologist III
Waikiki Aquarium,
University of Hawaii
2777 Kalakaua Ave.
Honolulu, HI, USA 96815
www.waquarium.org

808-923-9741 ext. 0 VOICE
808-923-1771 FAX

 

[PeterIMA]

Subj: Re: [Coral-List] coral feeding questions
Date: 6/2/2006 12:10:12 PM Eastern Standard Time
From: [email protected]
To: [email protected], [email protected]
CC: [email protected]
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Hello All:

I have been standing by reading the discussion about feeding by corals, an old discussion indeed which has been on-going within the coral community for ca. 40 years or more. Thus it seems we learn slowly! I think the reason for that is that for some odd reason we seem to have a greater tendency to be polarized than some other disciplines of science: everything has to be black or white, we don't like shades of grey (or gray either). As one who has worked with both autotrophic and heterotrophic aspects of coral nutrition, I never felt that I had to characterize corals as belonging to either camp, but rather I wanted to provide some quantitative information about such phyiological activities of the corals I studied. My opinion is that corals are blessed with very adaptable and varied trophic abilities that have served the group well over hundreds of millions of years. While there is no doubt that some reef species are quite dependent on their algal symbionts, others are ap
parently less so and thus do well at depth and in shaded areas where the zoox may be just passengers looking for a good shelter to live in. My first studies were on Astrangia danae (or A. poculata) a facultatively zooxanthellate species where the dark brown colonies were found deeper and under overhangs, while the white ones were more in the open...go figure.

More to the present ping-pong match: some old and recent references that (a) show that the multiple nutritional sources for reef corals has been long known and appreciated (Yonge 1973), and (b) some more recent studies that have shown that it's not just zooplankton that needs to be considered as heterotrophic food sources for corals. I remember being surprised in 1985 or 88 (getting old, can't remember which reef meeting) when Clive Wilkinson presented a paper showing data for coral filtration rates of phytoplankton (comparing them with sponges): I think he chose phytoplankton because he didn't realize the literature of the time told us that corals can't eat and digest such plant matter.

Yonge, C.M. 1973. The nature of reef-building (hermatypic) corals. Bulletin of Marine Science 23: 1- 15.

Wellington, G.M. 1982. An experimental analysis of the effects of light and zooplankton on coral zonation. Oecologia 52: 311-320.

Rosenfeld et al. 1999. Sediments as a possible source of food for corals. Ecol Letters 2: 345-348

Anthony k. and K. Fabricius. 2000. Shifting roles of heterotrophy and autotrophy in coral energetics under varying turbidity. JEMBE 252: 221-253

Houbreque et al 2004. Importance of a micro-diet for scleractinian corals. MEPS 282: 151-160

Houbreque et al. 2004. Interactions between zooplankton feeding, photosynthesis and skeletal growth in the scleractinian coral Stylophora pistillata. J Exp Biol 207: 1461-1469

As a final anecdote: back in the early '80s when I was doing nightly dives trying to pin-point coral spawning, I kept seeing the corals bulge their oral disks and then spit out stuff just at dusk as they expanded their polyps. The first few times I got all excited thinking it was the beginning of spawning. But syringe samples I collected, when observed under the microscope, showed the stuff to be made of : sponge spicules, zooplankton carapace parts, lots of marine snow like material that was totally unrecognizable, zooxs, foram tests etc etc. In other words, anything they could get their little tentacles on but couldn't digest.

As as a second final anecdote: a few years back a woman started a discussion on Coral-List suggesting that one reason corals were doing poorly was because as we overfish the world's oceans, we reduce the amount of N being cycled through these ecosystems. She suggested that corals may be mroe starved than they used to be when fishes living over the corals were more abundant. Judy Meyer showed back in 80s that corals grew faster when they had resident fish schools (Meyer, J.L. and E.T. Schultz. 1985. Migrating haemulid fishes as a source of nutrients and organic matter on coral reefs. Limnol. Oceanogr. 30:146-156.). In 1998 the worst bleaching year to date in the Florida Keys, inshore corals with large schools of grunts living on them bleached white as sheets in mid-June and were 100 % recovered by mid-September while more offshore corals that bleached later in the summer (temperatures heated up sooner inshore) suffered much death and tissue loss. These are the facts and I
cannot tell you for sure why these two populations responded/recovered so differently to bleaching, but I suspect it was the high nutritional state of the corals due to fish feces as a food source.

Regards,

Alina Szmant

*******************************************************************
Dr. Alina M. Szmant
Coral Reef Research Group
UNCW-Center for Marine Science
5600 Marvin K. Moss Ln
Wilmington NC 28409
Tel: (910)962-2362 & Fax: (910)962-2410
Cell: (910)200-3913
email: [email protected]
Web Page: http://people.uncw.edu/szmanta
******************************************************************