I've had direct experience with only one Flying Gurnard, a Gulf Stream juvenile D. volitans that I caught here in NJ. Flying Gurnards are basically botton dwelling fish that should be in an uncluttered aquarium with a roomy substrate. These fish walk on their pectorals, swimming and gliding mostly to get from one place to another. They eat the usual stuff found in sandy areas, like worms and small inverts. They have a large semi-square head, with very prominent bones. Mine had vivid blue dots all over its huge pectorals. Eventually it got too big, growing from about 3 inches to about 9 inches from one summer to the next, when I released it. I suppose a smaller species would work out better, but they are a very specialized fish, and fairly active. In general, I've found that deep water fish do perfectly fine in aquaria, as long as temps, light levels, and other parameters are met.