Hey all, I have this Pla Sawai (Pangasius Hypophthalmus) for quite some time now. His favourite food is Hikari Goldfish Sticks. But I noticed that he has lost some appetite recently. Oh and he has a cousin in the tank too, a Chao Phraya Catfish (Pangasius Sanitwongsei), which also loves Hikari. When I got the Chao Phraya Catfish, he was smaller than my Pla Sawai. Now, he is 2 times bigger. So what could be the cause of the lost of appetite of my fish?