Been encountering the things in Asian markets for years, and occasionally been curious, but who wants to buy an entire great long skinny fish just to find out what it is?
Well, a couple of days ago (before coming down with the cold) I stopped by a Korean market, and there were little segments of beltfish packed in modest quantities in styrofoam trays at a "might as well satisfy the curiosity" price.
For lunch today, I tossed a couple of segments (one amidships, one tail) into a pan with a bit of butter and lemon juice, and cooked them until they appeared done.
The result: the abdominal wall has rather a lot of little bones, and the belly is quite fatty for 'murrican tastes, so I spent a fair bit of time disassembling that segment. The tail segment was trouble-free in the small-bones and fatty-scrap departments.
As far as eating it goes: it's yer basic mild thin-skinned fish. More or less interchangeable with trout, and, around here, a bunch cheaper.
Overall, quite satisfactory. I probably won't go buying a whole one (having quite a small freezer), but, should I encounter a tray that's mostly tail segments? Yup.