Bichirs are incredible creatures. They are naturally almost totally blind and deaf, and hunt mostly by smell. Mine ate small cichlid pellets like crazy, bloodworms and such work too. The salted water you put him in probably did more harm than good. Most bichirs like heavily planted tanks so that can hide until feeding time, which can be anytime day or night. Since they are mostly blind anyway, they don't really have a "sleep schedule". As long as they have lots of plants for hiding places and soft, slightly alkaline water, they are perfectly happy. If your water parameters are different, an adaptation/aclimataion period may be needed.
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