Anthropomorphism, corals and you

[Brooke]

Get out the webster's! I've been meaning to get this question answered for a long time, so I hope some of you guru's aren't too busy this weekend.

Recently went to a reef club meeting and everything in this guy's tank was very expanded. His zoanthids, for example, were much more open than mine. His lighting was metal halide..not sure of the wattage or kelvin temp. This got me thinking. Were his corals "happier" than mine? Did they have to expand more to get more light? Are my corals "happier" because they do not have to expand so much? How can we truly gauge the health and vitality of the corals in our tank. Is being large, expanded, fluffy, full, etc. the best indicator of the coral being in the ideal environment?

Instead of expansion, should we be looking at factors like division, budding, general growth, color, etc.?

Any insight into what a coral really looks like when it's happy would be great.

Thanks-
Brooke

[gregt]

Good insight brooke.

I've noticed that my big hammers don't expand as large since I started using Jerels blender mush. I think it's a good sign that they aren't forced to expend as much energy to meet their needs.

[MontanaRocknReefer]

It seems to me that I read that temperature plays a big role in the corals expending energy as the higher the temperature the faster they grow and would be more fully extended. So I would think that on a wild reef with rainy days, cloudy days, etc the temperature would vary and corals would show different appearances according to climate.
So as with everyone tank being just a bit different in temp, water current, etc you may see corals acting differently in one tank as compared to another with the same corals and it would mean that your coral were not healthy but adjusting to suit their needs! Johnny

[Steve Richardson]

dissagree to some extent.

I think to infer that a coral os 'straining' because it is fully extended makes us guilty of a kind of anthropomorphism too. Or perhaps a rationalization that they are just as 'healthy' even though we dont think they look as nice.

Personally, I like it when they are 'living large'. They look better and in my experience, are the specimens that live longer and reproduce more readily. So as Brooke mentioned.... color, growth, etc... seem to me to go hand in hand with it.

random comments,

[gregt]

Hi Steve, thanks for joining the conversation.

It's very difficult to talk about "corals" because rarely do they all fit into the same mold. Some will extend only to meet their energy budget and immediately retract, and some will stay extended almost continuously so long as there is no physical attacks on them.

One coral might be retracted because the lighting is too bright One might be retracted because it's not been getting the proper food sources. Another may be retracted because it's energy requirements are met.

I guess what I'm saying is it really depends on the specific situation.

I consider growth to be the ultimate tell-tale. Rarely does an organism waste energy on growth before it's basic needs are met.

Problem with that metric is you can't tell there's a problem until it's been occuring for awhile.

[Spanky]

I agree with Greg 100% on this one.

Plus, in cases dealing with photo corals, I think it would benefit to sometimes think of them more as plants than animals.


Jerel

[FishDaddy]

This is almost a mystical topic, requiring application of "The Force" to determine how healthy your corals are and what needs they are asking for. Appearance and growth are about all we can go by to judge our coral's health. Fish do exhibit some behaviours that can give us clues without showing any changes in appearance.

I read a discussion once, can't remember the participants but they were among the leading "experts", about light and feeding as affecting coral health. One was a proponent of more feeding, creating a very nutrient rich environment, and reported superior growth and expansion. Maybe if I have time, I'll try to dig up that old discussion.

I would think that good growth and full expansion would be the desired state for our corals. Seeing corals in the wild reef, none appear to be only partially expanding because they are "satisfied". From my limited observation and knowledge, corals will use all the nutrients and good lighting available to achieve their main objective, (as if we knew what corals think ) which is to eat and propagate themselves. Food and procreation seem to be the primary common natural motivators of wild animals, from single-celled organisms to primates. Only man seems to divert himself from these natural instincts to adopt other primary interests, such as football, beer, and computers!

I wish we did have an objective way to measure coral health by test kits, as we measure Ca and Alk, but I'm afraid that until Dr. Doolittle learns to translate coralspeak, we'll just have to get by with "The Force"!
Dick

[gregt]

Dick,

What about those corals that in nature don't typically expand at all during the day? They are able to meet their energy budget by feeding at night. When put in an aquarium, typically they expand only during the day.

Is it a good thing or a bad thing if they extend during daylight hours in our tanks?

Rhetorical question, just provoking some thought.

[FishDaddy]

Good point, Greg. This is another example of "Animals don't always exhibit the same behaviour in captivity as they do in the wild". This is one of the inherent imponderables with reefkeeping. Just what do our corals want/need to cope with the captive environment and continue with their dual missions of eating and procreating?
Most animals will exhibit a degree of adaptation to new surroundings. Those that cannot adapt will suffer and may not make it. Those that have flexibility to modify their behaviours will adapt, some to the same level as in the wild, others merely subsist. Since no two reeftanks are the same, the degree and method of adaptation will vary.
Dick

[Spanky]

Then there's the one's that contain zoox that have to adjust for cloudy days and sunny days. In this case they reach a happy medium and expand for only a short period of time on a sunny day, and might be expanded all day on a cloudy day.

[FishDaddy]

Absolutely, Jerel. That is why I think there are no absolutes with respect to organisms that have the ability to adapt to varying conditions. Photosynthetic corals are going to be dependent to a great extent on their zoox as to how the coral itself responds to differing light conditons.
A reef tank with lights on timers is going to have more consistent day-to-day light conditions than the natural reef. Certainly never as good as natural sunlight, but more consistent nevertheless. If an aquarium coral is exhibiting different behaviours on different days, or over time, light being the same, then there must be other variables, such as feeding, water quality, etc., that are affecting them.
Dick

[FishDaddy]

BTW,
I'm probably waaay over my head here, but giving my best impressions on how I think corals respond!
Dick)

[Brooke]

Well, of course you can't compare all corals into one big bunch...but what if, as in my case, you were comparing apples to apples. His zoanthids were wide open..mine stay more upright in a tight group that is growing well. It just made me wonder if we put too much stock in.. " my anemone is happier under vho because it's expanding more". I see this kind of thing a lot on the boards.

At the very least it makes us go and take a good look at our tanks .

Brooke

[FishDaddy]

Exactly, Brooke!
But all of us have apples, oranges, pears, plums, and a few crab apples, in our tanks! Even with the same exact species of Zoanthid, they may live very different lives in different tanks as no two tanks can be the same. Even with matching water tests, there will be other organisms present that can affect the chemical makeup of the environment, such as leathers, Palythoa, etc.

I have species from Caribbean as well as different places in the Indo-Pacific; photo and non photo. It sometimes seems a constant battle to keep everybody happy! If you make adjustments to liven up one coral, another may not like the change.
There has to be a good deal of educated guesswork and effort in trying to reach some balance to keep all the corals as healthy as possible.
Dick)

[Spanky]

you were comparing apples to apples. His zoanthids were wide open..mine stay more upright in a tight group that is growing well

Ahhhhh, but all zoox are not created equal either. You might (and are probably) dealing with a different zoox, or even a different quantity.

Different levels within the system can come into play too.

Expansion is not a good indication of health/happiness, it can actually be the opposite.


Oooouuuuuuuuummmmmmmmmmm