So, I just got my first baby black arowana. I had him on hold for 2 weeks before the pet store felt comfortable allowing me to take him home, as he still had is yolk sac when they received him. He's only about 2 inches and I have him in a 10 gallon with some pregnant ghost shrimp at 80 degrees. The only thing I can get him to eat are little crushed up bits or freeze dried krill, but he eats those aggressively. He'll grab at all other foods that float, but spits them out. Here are some shots of 'Mr. Black':