Here is some info on feeding from wet web media.
"Thawed krill, shrimp silver sides, various "frutti de mar" are fine if foods if they are finely shredded. Feeding large whole prey that is larger than the mouth otherwise can be harmful to an anemone in the long run. Most meaty foods of ocean origins are fine (Pacifica plankton, Mysid shrimp, fish roe, etc). Terrestrial and freshwater foods should NOT be offered... they're not totally digestible, nor nutritious... Yes, this includes "feeder" goldfish here as well.
Some folks feed their carpets very infrequently (a few times to about twice a month) not wanting to experience too rapid growth. Do bear in mind if there are fishes present, and/or a thriving refugium with a DSB... they'll also get a fair amount of stray fish food and "fuge" foods. This being stated, there are folks who feed these "eager eating" animals a few times per day... There is some evidence that such frequent feedings do encourage aggressive feeding behavior (tankmates)...
Regurgitated food, and waste pellets of such should be promptly removed by vacuuming of netting. "
Also from them on the open mouth
" The usual criteria apply for picking out a healthy Carpet Anemone... that the specimen is open (will likely greatly expand after acclimating... are "squeezed" down for shipping...), w/o apparent tears to the base, that the mouth not be totally gaping... And the acid-test for all marines: that it be feeding.
Newly arrived anemones are not a good idea to purchase... Put a deposit down and leave prospective buys at your dealers for a good week.
And do avoid "all-white" carpets... these are not healthy, but bleached specimens that have lost their natural endosymbiotic algae... and will very likely perish, rather than survive the span of time et al. it takes to reincorporate these symbionts. "
i guess its not hungry maybe just stressed out.
