Where are my dentures?
A chain moray (Echidna catenata) found much deeper (10m) than usual. Chains don't have the long, sharp teeth common among the other morays because they are not primarily fish eaters. Instead, they go after crabs. Hence, they tend to be found in shallow waters, sometimes in tidal pools. And their blunt teeth are adapted for crushing shells, which gives them a "I am missing my dentures" look about them.
Although the open mouths of morays can be a bit intimidating, it isn't actually an aggressive sign - they open and close their mouths to pump water over their gills.