My tiger shovelnose catfish and my arowana used to eat shrimp everyday and are both growing nicely both about 16'' last week they both just stopped eating altogether. I have done water changes to no avail and they don't have any physical signs other than a couple of the Tsn's barbels have deteriorated, they swim around freely, no odd behaviour. Please help I'm starting to worry they must be hungry it's coming up on 2 weeks.