Feeding xenia

[Dolfan0925]

What do xenia eat? Do they eat Phytoplankton?

Thanks,
Tony

[argo]

Page 153 of Eric Borneman's "Aquarium Corals" - Xenia feed by nutrient uptake; supplemental feeding - photosynthesis (light). So, if you feed your fish then Xenia will receive enough nutrients - no specialized feeding is needed. Some reefers keep Xenia for extra nutrient export.

[Dolfan0925]

so cyano algea thrives on nutrients. Would xenia feed on the nutrients that the cyano feed on and lower the algae? Because I have such a bad outbreak of red slime.

[argo]

Xenia will not help reduce the amounts of nutrients in your tank (not on a significant scale and not fast enough to prevent proliferation of cyano). Read up on the causes of cyano outbreaks - mostly high nutrients and high phosphate. How's your tank stocked in terms of number of fish? Are you overfeeding? How do you export nutrients and phosphate? How long has your tank been setup? Water specs, water volume and lighting info will also be needed for the forum's experts to give you sound advice (see also the rules for posting at the top of this forum).

[thedude]

I've always gone with the consensus on how xenia feed, i.e. nutrient uptake, but I've noticed that when my cyclopseze begins to circulate all the xenia act like they've caught something. They close up momentarily and then reopen. They don't do that with the mysis or phyto.

I'm not sure if they are catching them, but it sure looks like it. Guess I'll have to watch more closely.

[MiddletonMark]

Well, my xenia don't appear to eat anything ... I rely on dissolved nutrients and turkey-basted detritus stormed from time to time to feed them.

As argo said, the cyanobacteria is not likely to be significantly affected by the xenia's uptake of nutrients. Slightly, but if you have lots of cyano ... that I'd deal with thru your practices and likely make sure the skimmer and equipment are well suited for what you're doing.

[thedude]

Yeah, I'm still doubtful that they are eating anything. It just caught my attention.

Although, you'd think with the shape of the end of the polyps and the pumping that they are trying to catch something.

[EricHugo]

or trying to cause net flow of water through the polyps for dissolved organics, as has been found in one study? They lack mesenteries...cannot digest food even if they captured it. No nematocysts, either.

[thedude]

Wow, didn't know about no gut. That is definitely a very basic little life form, no digestive tract, no capture devices. Leans more toward the plant side.

[EricHugo]

yes, and since corals were without symbionts before they had symbionts, I would say they might actually be more advanced.