I got my ones onto frozen quite easily. I found that they are primarily nocturnal feeders (the big eyes are a give away) and once the tank lights were off and the room lights dimmed they were quite wlling to strike at anything that hit the surface. The food had to make a splash for them to be aware of it so i had to remove the tank cover and throw the food into the tank from 8-10 feet away, this also prevented spooking them by causing movement near the tank as they are very nervous fish. I still employ this method to feed new fish that are reluctant to feed.
I would love to try some Hydrolycus species again but they have such a poor survival rate in captivity that i worry about the ethics of keeping a fish that lasts a year at best in a aquarium, i managed to keep my pair alive for around 6 months and grew them to around 10 inches before they both died within weeks of each other from completely unknown causes.
