Thank you, I understand the gravel concern. That is actually planted aquarium substrate and is finer than most gravel. He should be able to pass any accidentally ingested substrate. Also i hand feed him so he isn't eating from the bottom of the tank minimizing the chances of him actually ingesting any. The lake from which they originate Xochimilco is a mud bottom lake generally mud is very fine but definitely has larger pieces in it generally organic matter etc. there should not be large enough chunks to cause an impaction in this substrate. Too, impaction most commonly happen in amphibians and reptiles that are in poor health and isn't always caused by the simple ingestion of matter more often its the poor health reducing the bodies ability to pass minor obstructions or items so they become major and life threatening.
