i feel bad for the guy that started the thread im giving a link to... but it does prove that they can try and eat more than is good for them.
dont fret though, i used to have a delh and it came back from jumping out of the tank and flopping around so much it made itself bleed. so maybe your little fishy will be just fine. it is a good lesson though for why people should not put bichirs in tanks that have gravel.