My GBTA goes ga ga for krill, raw shrimp, squid, etc... Try little pieces at first, hand feed or use a turkey baster to gently push the piece of food into its tentacles. It should grab.
A wise women once said, if its too big she'll just spit it out.
Oops that sounded all wrong, I was trying to compliment Myka as I have had draw upon her wisdom a couple times.