Think it belong to the grouper family. Trying to adapt it to frozen and pellet food. Mostly 'meat eater, worms and such. Did a search in google and some even feed it with small guppies/goldfish!
Quite a slow-motion eater, if tank filled with fast-moving eaters, then probably the rest will out-compete the comet. And to my observation, it prefer to hang out at darker corners of the tank.