Acropora 'Target Feeding' Response with Particulate Coral Food

[chcgregg]

Hi guys,

I filmed a few species of the Acropora I keep to see what their response was to being target fed Ocean Nutrition's 'Reef Pulse'. The Acropora didn't seem to directly ingest any of the food, but did capture some, only to release it with mucus a few moments after being filmed.

I will be testing other foods in the future with more of a scientific basis and which provide evidence as to capturing, ingesting, and digesting foods.

feel free to watch the video!

Does anyone here target feed their Acropora? What do you use if you do?

Regards,
Callan

 

[bacc2bacc]

Awesome video! Doesn’t seem like sps want to eat much!

 

[C. Eymann]

You should be feeding in the night/dark cycle, that's when they are in "feed mode" the axial corallite polyps will be fully extended, unlike radial polyps, axials contain little, if any zooxanthellae, they are specifically for food capture.

very cool experiment! please keep us updated!

 

[crusso1993]

Hi guys,

I filmed a few species of the Acropora I keep to see what their response was to being target fed Ocean Nutrition's 'Reef Pulse'. The Acropora didn't seem to directly ingest any of the food, but did capture some, only to release it with mucus a few moments after being filmed.

I will be testing other foods in the future with more of a scientific basis and which provide evidence as to capturing, ingesting, and digesting foods.

feel free to watch the video!

Does anyone here target feed their Acropora? What do you use if you do?

Regards,
Callan

+1 on @C. Eymann comment.

Thanks for sharing the video. It will be very interesting to follow along and see the results! Following...

 

[chcgregg]

You should be feeding in the night/dark cycle, that's when they are in "feed mode" the axial corallite polyps will be fully extended, unlike radial polyps, axials contain little, if any zooxanthellae, they are specifically for food capture.

very cool experiment! please keep us updated!

That's another test I will be doing, it's a follow up to this one using the same food. Thanks for the suggestion!

I have read quite a few scientific papers, with a few detailing that capture rates are slightly higher during the daylight hours for Acropora tenius and Acropora millepora, but I am still going to test it.

The Acropora tenius and A. millepora seem to have more polyps out during daylight hours than in dark, where as the A. abrolhosensis and the unidentified staghorn have more radial polyps present during dark hours. Makes me question how much these corals have adapted to being aquacultured for years in captivity.

 

[chcgregg]

Awesome video! Doesn’t seem like sps want to eat much!

Thank you! It seems the case, in daylight hours anyway! Could be a combination of a few things but I hope to figure out if it is light related or the food used.

 

[chcgregg]

+1 on @C. Eymann comment.

Thanks for sharing the video. It will be very interesting to follow along and see the results! Following...

Thanks!! Yeah, I am interested as well.

 

[lemonade]

As you observed Acropora exhibit a stress response to the target feed. Acropora slime up, and send out mesenterial filaments for protection. Great video, btw.

 

[chcgregg]

As you observed Acropora exhibit a stress response to the target feed. Acropora slime up, and send out mesenterial filaments for protection. Great video, btw.

It isn't a feeding response by far. As noted with many LPS, they will enlarge polyps to increase surface area to capture more food, this is quote the opposite to that. All particulate foods I have tried will exhibit the same response.

Thank you for your support!

 

[Daniel@R2R]

I broadcast feed. I've never target fed an acro.

 

[chcgregg]

I broadcast feed. I've never target fed an acro.

I usually broadcast feed also, but I am still unsure whether or not they will actively capture and ingest particulate foods. It could also be dependant on what types of food can be captured, as some foods, as seen in the video, irritate the coral more than provoke a feeding response.

The key here are particulate foods, not other foods such as zoo plankton which are proven to be 'eaten by Acropora.

 

[Mathman]

I know that all of the old school metal halide reefees used to keep sps without ever "feeding" directly. Do we know with certainty that it is even necessary?

 

[chcgregg]

I know that all of the old school metal halide reefees used to keep sps without ever "feeding" directly. Do we know with certainty that it is even necessary?

Corals have a symbiotic relationship with a Dinoflagellate called Zooxanthellae. It produces a large amount of the nutritional requirements for the coral, but not everything. Corals get the rest of their nutritional requirements from external foods.

Fish waste will also is a food source for corals, as it contains amino acids and nitrogen, which the corals utilize.

So with metal halides, they contain a very wide range of the spectrum required for efficient photosynthesis, even some infra red wavelengths which helps photosynthesis of the Zoox, and the more usable light, the more efficiently and effectively the Zoox can create food for corals.

 

[chcgregg]

Supplementing foods for Acropora has been found to increase growth rates significantly as opposed to not being fed. I am testing a few foods to see which ones are captured and ingested.

 

[jeffww]

I think acros don't like puffs of water from a new direction and so the polyps retract and fail to eat. I have seen my acros actually suck in strands of reef roids trapped in mucus with the pumps off after broadcast feeding.

 

[chcgregg]

I think acros don't like puffs of water from a new direction and so the polyps retract and fail to eat. I have seen my acros actually suck in strands of reef roids trapped in mucus with the pumps off after broadcast feeding.

As you can see in the video, I blast one of the Acropora with just water from the feeder and the polyps do not retract.

 

[jeffww]

That's probably because they are being exposed to a lot of particulates and getting stressed. It takes time for them to actually undergo a feeding response.

 

[chcgregg]

That's probably because they are being exposed to a lot of particulates and getting stressed. It takes time for them to actually undergo a feeding response.

The issue here is capture and ingestion. I have used foods which have been captured and ingested, but this particular coral food, when target fed, stresses out the coral.

This post is about the response to being target fed particulate food from Ocean Nutrition, not a summary of every particulate food. Other coral foods might prove a better result.

 

[chcgregg]

Frozen Cyclops target fed to Acropora tenius

20 minutes later. The Cyclops has been ingested completely.

 

[chcgregg]

3 hours later and the partially digested Cyclops is being spat back out.