Coral feeding and You! (A Primer for new feeders!)

I got a lot of questions and comments about my last FS post in which I referenced feeding my corals so I figured I would go ahead and share my knowledge of corals and the care there of for the GIRS members to learn form as well.





Let's Start at the very beginning.


What is a Coral?


Many people learn to keep corals without really knowing what it is they are keeping.


A coral is an animal, specifically, a marine invertebrate in the class Anthozoa of Phylum Cnidaria, typically living in compacted colonies of many identical individual polyps. The 'head' of a coral is a colony of many genetically identical polyps. Each polyp is a very small spineless animal A set of tentacles surround a central 'mouth' of most corals. An exoskeleton is excreted near the base and over many generations, the colony creates a large skeleton that is characteristic of its species. Individual heads grow by asexual reproduction of polyps which is the typical reproduction method we hobbyists see. Corals can also breed sexually by spawning: polyps of the same species release gametes simultaneously over a period of one to several nights around a full moon but this is an event that almost none of us will ever see in our aquariums.


Most corals Contain stinging cells on their tentacles, like those in sea anemone and jellyfish, which they can use to catch plankton and fish, most corals obtain the majority of their energy and nutrients from photosynthetic unicellular algae that live within the coral's tissue called Zooxanthella (also known as Symbiodinium) Such corals require sunlight and grow in clear, shallow water, and are typically the corals that we the hobbyist keep!


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Now that we have a better understanding of what we are actually raising in our aquariums it's time to take a look at some of the options we have for our coral care. Specifically feeding. This articles going to take it as read that you have your lighting set up and running, and have noticed no extreme coral die off in your aquarium.


Feeding Corals...?


It should be no surprise that I am a huge proponent of coral feeding, and the basis for this is the development of corals in the wild. We know that corals have a symbiotic relationship in which the Zooxanthella in their cellular structure that provides energy from the sun, but we can also see that they have evolved special physical structures that help them consume foods. A set of tentacles, and a mouth are usually good indicators that a species is looking for more than just the sun sugars they are getting. In fact, many types of corals like to eat, and will readily do so!


Now to the Details!





Feeding A coral... I thought it was a fancy rock?: What we are talking about when we talk about feeding corals is target feeding of corals specifically. To do this, we want to make sure the fish (and inverts) in the tank have been fed, considering they will snatch up food from the corals themselves. We also want to go ahead and turn off all the pumps in the system we can. And we will touch on exactly why we want lower to noer flow in the system here shortly.


What to Feed?: There is of course no best answer for this. Like our fish we should look at a wide and varied diet for the corals to provide the best overall variation of diet! There are a number of coral foods now a day's including things like Fauna marin, Coral Chili, and Rod's foods is even making a coral blend now. More often than not, you can certainly use what you are already using. Specifically your frozen foods, or self prepared frozen foods. Now most corals are looking for smaller particulate matter, so the easiest way to feed and the quickest answer to what to feed, is 'that cloudy stuff'. When you mix up your frozen foods, the denser large particles settle to the bottom, 'That cloudy stuff' is called supernate (YAY Chemistry terminology!) and that is our best option for starting out feeding corals with frozen foods! Some LPS prefer larger meaty chunks and we will outline those corals a little bit later.





SO! now we know what to feed, so who do we feed? The short answer is EVERYTHING WE CAN! Feed ALL The Corals!


Joking aside, we know that in nature all corals eat to supplement their growth. So we can say that all corals eat, but let's break it down a little bit.


Now I typically try to avoid opinion in informative guides, but there will be a mix of Empirical data, along with some anecdotal data to follow and personal observations. Based on my own and many other inputs through the years. Please note, this is not the end all be all list of coral feeding guides, and will be updated as new information or evidence comes to light! This is simply a quick guide to getting started in taking care of your corals!





LPS: Most LPS are hardy eaters, and should be high up on your list of who to feed.


Most LPS will jump on the chance for a feeding and most will prefer a good meaty mix of supernate and finely ground/chopped krill, brine shrimp and mysis. The most notorious eaters I can think of are Elegance corals both branching and walling) as well as Duncans. Feeding here is very straight forward. And I have seen both of these coral types eat just about anything. Target feed and go!


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Quick Tips for specifics: A list of helpful hints for feeding specific LPS



Blastomussa/Pineapple:


Similar to Chalice, a prefeed is a good way to start, and once you get the feeding tentacles out, it is amazing just how much they will eat!





Acanthastrea:


Acans are one of the enigmas in the last 5 years in my book. I expected them to be as popular as Zoas, due to the large number of color morphs and super easy propagation, but what many hobbyists observed is that they started dying off in the long run. And many people lost large colonies. The reason for this...? They were never fed! Acans that are fed regularly will spend days with their feeding tentacles out, and probably anecdotal evidence, but those that do, tend to be healthier colonies than the ones who are fed less regularly and retract their tentacles. Remember tide pools and reefs are VERY nutrient high areas of the sea! You can feed these corals almost as much as you can an NPS with little ill effects!





Acanthophyllia:(only recently reclassified and were previously known as Scolymia or Cynarina or the other meaty varieties) Again very hardy eaters, and very dramatic changes when they eat. These are a little easier to feed, once they get a hint of food in the water column they will open right up. and you can feed from there. Typically they are ready to go once the fish have been fed.





Brains:


Slightly Different Than many LPS in that while they do have feeding tentacles, but do not put these tentacles out often. They tend to feed like some encrusting SPS in the sense that they use a mucus net that they cover themselves in. This is part of the reason that they prefer slower currents and flows as to not slough away the mucus net and cause a slow and sad death. To feed, GENTLY target feed the coral, and let stand for 15-30 minutes. The coral will slowly pull the mucus net into their mouths and away they go! Smaller meaty food varieties are a good bet here.


Chalice Corals:


Similar to brains, while they do have feeding tentacles that surround each polyp they depend on the mucus net to pull the food in. Low flow and a fair amount of time is the best bet to get the best feeding results from these guys!


Fungaia :


Similar to Brains they use a feeding mucus net to consume their food. Dust with feed, and let stand for 15-20 minutes. The amazing thing about Fungaia is the actual amount they will consume in size. If they can get their mouth around it, they will eat it, and I have personally seen a two inch disc eat a one inch silverside without a flinch.





Caulastrea/DesktopModules/ActiveForums/themes/_default/emoticons/sad.gifTrumpet Corals)


Like most LPS a light dusting and a wait of about 5-10 minutes until the feeding tentacles come out. this is again one of those corals that may surprise you in the amount that it can and will actually eat!





Euphyllia Corals: ( hammers, frogspawn torches)


While Euphyllia will eat, it is hard to actually find a good food for them, I have noted that some Torches and hammers prefer supernate that is lightly dusted with phytoplankton. Dust very lightly with these types as they will shy away from food if it is shot at them too fast. If you know any good foods for these guys please share!


Lastly for the LPS Specifics:


Tubastrea/Balanophyllia: NPS (Non Photo Synthetics)


This should go without saying considering these species are NPS. Meaning they do not contain Zooxanthella bacteria, and require feeding to live period! They should be fed daily or every other day to keep them alive.


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Polyped Corals


ZOA:


This is going to spark some debate I am sure. But I will tell you right now, Zoas don't eat well. Now with that being said, there has been a HUGE movement lately to target feed zoas, and lots and lots of 'speculation' as to how much more growth zoas that are fed will have. I agree that zoas should be fed. But I strongly believe that (due to my observations and other hobbyists who I trust along with a handful of professional coral propagators) Zoas are not hardy eaters. We know anecdotally that Zoas are some of the corals that do better in 'bad' water. Or water that is a little on the dirtier side. I also know from my experiences that when I am dosing Vodka I see a good boost in Zoa production. I think the proponents of target feeding Zoas are only looking at the surface level when they feed and not digging in a little deeper. From my experiences it looks like Zoas benefited from target feeding in the sense that the over saturation of nutrients in the water help to produce higher amounts of nitrates and phosphates, and this in turn causes a bloom in bacteria and algae that the Zoa eat. If you have the ability and a macro lenses, set up a video recording of a target feeding of Zoas. You will find that Zoas are actually notoriously picky eaters. and while initially may react to the feeding, over time you will note that it is more of a shying away from the feeding. and they consume little to none of the actual food. I am suspect that phyto and zoo planktons are a better supplement for zoa rather than target feeding of supernate (in my case I mix in Phyto and zoo plankton to my prepared foods so my supernate is more geared toward overall tank happiness) I am sure there will be kick back here. And I welcome open discussions. But let's keep things civil.


Paly:


On the other hand... There is the Paly... The Paly will eat a horse. They are very active feeders and will take not only supernate but also a good size chunk of fleshy foods too much like an LPS! You can feed Paly as often and much as you feed some LPS with little ill effect. You will not need a macro lense or time lapse to watch these guys eat. they go right for it!





Gorgonian/Fans:


Fans and gorgonians benefit from target feeding of supernate to their general area. And whilst polyps are extended. Give a dusting to the general area of the coral but not directly on it as this will cause the polyps to retract. Supernate mixed with a bit of plankton will help a good deal.


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Softies:


Many softie corals feed on the planktons and nutrients in the system itself. I do not target feed softies. And often misunderstood with Xenia, is the pulsing is not related to feeding (directly) but to move water as they are typical of low flow areas in the reef. With that being said, Xenia, Anthelia, Tubipora,Briareum, Clavularia, and Sympodium all seem to do well in a fed aquarium, but I have never seen a direct response either initially in time lapse, and or in the long run from long term targeted feeding.


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Corallimorphs: Mushrooms (Ricordiea, Discosoma, Rhodactis, Actinodiscus)


While this is not well know, Corallimorphs are VERY hardy eaters! Feed your mushrooms! I have seen them eat both prepared frozen and dried foods, the key here is very low flow, and target feeding near the mouth. They key here is low flow for them to take it all in.


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SPS: I have a bone to pick with SPS in general, and I think that in the last few years, SPS has migrated from actually SPS systems, to being realistic, specific to Acropora. And we can start an entire discussion on this later.


I have no specific feedings methods for SPS. Similar to Gorgonians and fans, Target feeding is helpful but a general area feeding is more beneficial here.





** Still work in progress but time crunched so posting for open viewing. Please PM me any questions or typos**