Coral IDs?

[daniejd]

Hopefully this will be easy, just got 4 coral from the discount rack at LFS, so they are in a bit of recovery mode. They were all identified as Favia, but they look different enough that I’m not positive of that. Any thoughts?

[mitten_reef]

Two on the left look like micromussa genus. The two on the right, idk. I think they’re harder to id when their feeding tentacles are wide open like that

[daniejd]

21 minutes ago, mitten_reef said:

Two on the left look like micromussa genus. The two on the right, idk. I think they’re harder to id when their feeding tentacles are wide open like that

Thanks, I was thinking along the same lines, I’m guessing the far right is Favia or whatever the latest name is. The lump I can’t guess, he has recovered the most (he started out really retracted, just basically a colored skeleton). Probably has a way to go, though I have no idea how to make him eat, he puts out those tentacles, but doesn’t grab any food.

 

 

 

[mcarroll]

On 1/10/2023 at 9:36 PM, daniejd said:

Probably has a way to go, though I have no idea how to make him eat, he puts out those tentacles, but doesn’t grab any food.

Most corals are somewhat specialized in their feeding habits, so they aren't that good of eaters in aquariums.  We usually don't have the right food or flow.  If you watch time-lapse videos, a lot of food they catch and "eat" they end up spitting it back out.  (Most videos of corals eating don't actually show much....hard to find a good one.  Why does every YouTuber think they are a dramatic movie director? 🤣)

 

How are your dissolved nutrient levels?  NO3, PO4?

 

 

[daniejd]

8 hours ago, mcarroll said:

Most corals are somewhat specialized in their feeding habits, so they aren't that good of eaters in aquariums.  We usually don't have the right food or flow.  If you watch time-lapse videos, a lot of food they catch and "eat" they end up spitting it back out.  (Most videos of corals eating don't actually show much....hard to find a good one.  Why does every YouTuber think they are a dramatic movie director? 🤣)

 

How are your dissolved nutrient levels?  NO3, PO4?

 

 

Haven’t tested it. It’s a pico size tank with 50%+ water change weekly, more of a hospital tank, so I imagine it’s pretty good. All the coral have improved a good bit from when I bought them, so guessing they like the water. Even the lump (maybe favites?) that doesn’t eat has added some flesh.

[mcarroll]

22 hours ago, daniejd said:

Haven’t tested it.

That's the only way to know.  🙂  Let us know if you decide to.   With a hyper-aggressive water change schedule like that, it's likely to be a problem – nutrient levels eventually hit zero.  When PO4 does, corals start going downhill...eventually it can kill them.  There won't be a visual indication until they have already suffered damage from it.

 

So I understand the corals are looking better – that's a separate question though. 👍

[daniejd]

On 1/14/2023 at 9:22 PM, mcarroll said:

That's the only way to know.  🙂  Let us know if you decide to.   With a hyper-aggressive water change schedule like that, it's likely to be a problem – nutrient levels eventually hit zero.  When PO4 does, corals start going downhill...eventually it can kill them.  There won't be a visual indication until they have already suffered damage from it.

 

So I understand the corals are looking better – that's a separate question though. 👍

Measured phosphates. .08 Also got the lump to eat, with the pump off, he eats nothing, but if I turn it on, and let the food just swirl around him, he eats fairly well. One question though, are phosphates needed if you are feeding coral, wouldn’t phosphates in the food supply whatever they need?

[mcarroll]

2 hours ago, daniejd said:

One question though, are phosphates needed if you are feeding coral, wouldn’t phosphates in the food supply whatever they need?

That's a loaded question.  🙂  Sorry in advance for the length of the answer...I kinda wandered through it.  😄 

 

My answer is "Yes.  But, no."

 

If you can spoon-feed a specific polyp, then you might have control over feeding.  But how many corals can you have that level of control and precision with?  

 

It would be VERY limiting in terms of which corals AND in terms of your time.  

 

You could spend all day (or longer) trying to hand feed a single colony, depending what coral we're talking about.

 

Once you get past hand-feeding specific polyps, you're more or less talking about broadcast feeding.  

 

This is more realistic from the reefkeeper's point of view.  But opens up the can of worms on the coral's ability to capture and digest prey.

 

In general, our corals are unreliable eaters because of the combination of things it takes for a sessile animal to capture and eat food.  

 

Some corals require flow.  Some corals require no flow.  Without the right flow, they don't capture much or anything.  In a fish tank, that kind of messy feeding will wreck the ecosystem in short order.

 

Just an example of one aspect of the feeding issue which has diametrically opposed requirements and problematic features.  

 

It's actually way more complicated than that because prey-size and composition and other things matter too.  (Link)(Link)

 

Main point to the links is to note all the issues around successful feeding.

 

Probably worth noting that unfiltered seawater (with ALL that entails) was always one of the best "foods" in all the tests, even where it wasn't #1 best.

 

For perspective....

 

Still-living coral ancestors are bottom-of-the-sea carnivorous scavengers.  They still make skeletons in some cases.  But they are not photosynthetic at all.  

 

In some areas with abundant food sources, you might find these types of corals (different species of course; eg Sun Coral and other Dendo species, etc.) dominating photosynthetic corals.

 

Our corals, by contrast, leverage dissolved nutrients and their symbiotic photosynthetic partners (dino's) to create the monumental "surface reefs" we know and love.  

 

Our corals eat – but it is definitely not their main mode of nutrient acquisition.

 

SIDE NOTE:  Check out the article Nitrogen cycling in corals: the key to understanding holobiont functioning?

 

In fact, their uniqueness lies in that they do not have a main mode.  

 

With that uniqueness, they surpass the limitations of their dino's as well as other types of corals.

 

In general, ecological specialists tend to be more vulnerable to ecological change.  Carnivores and herbivores do not do well during extinction events, for example.  Too specialized on particular prey items or modes of eating.

 

That is why our generalist corals are still with us and have not disappeared in spite of major climate changes in the past, including all the major extinction events.

 

They use dissolved nutrients to prosper even when there is no food – or no food they are able to eat.  

 

Most of the time, most corals in reef tanks are making use of dissolved nutrients and/or naturally occurring food (eg detritus).  Yours won't be exceptional.

 

Even in the wild, under optimal conditions in locations where corals choose to grow from newly settled polyps, eating is only about 1/3 of consumption on average, per that article.  

 

Feeding your fish and letting your fish feed the corals is also usually the most ideal way to feed corals in a reef tank.....most corals seem able to use this form of food.  (ie detritus)

 

 

[PJPS]

On 1/16/2023 at 11:13 AM, daniejd said:

Measured phosphates. .08 Also got the lump to eat, with the pump off, he eats nothing, but if I turn it on, and let the food just swirl around him, he eats fairly well. One question though, are phosphates needed if you are feeding coral, wouldn’t phosphates in the food supply whatever they need?

Depends what you’re feeding.  Probiotic (coral frenzy, benepets, etc) don’t add phosphate, non-probiotic (reef roids, reef chili, coral dust, etc) do.  Keep phospates around 0.1.  Too much (mine are .35) is so much better than not enough.