Sorry for not being able to upvote.

The fish is an Empire Gudgeon, Hypseleotris compressa, part of the Australian goby complex. The pictured fish is a male, denoted by the red finnage.

It has no relationship to the snakeheads or bowfin families.

It is an ambush predator, hiding in caves or logs and snatching its prey suddenly and aggressively. DO NOT KEEP WITH SMALLER FISH!!! They can fit something up to their own body weight into their cavernous mouth and stomach.

Breed in caves, with the male providing limited egg care, but no fry care.

First bred in the early 1990s (I was one of the first I could find), infusoria and tank mulm provided the trick to getting fry to survive past a couple of weeks.

THIS IS A POSITIVE ID. DEFINITELY THE EMPIRE GUDGEON!