Vieja bifasciatus guarding a nest

Vieja bifasciatus guarding a nest.

This pot was actually laid on its side a few months back. But for some reason it got flipped upright during one of the pair's spawning sessions. Afterwards I deliberately laid it flat again; a few days later I saw it standing back up with the parents hovering above, on guard. Peek inside and you see eggs straight away. From then on, the fish always spawned well with the pot standing.

Behaviorally, a standing pot has a huge safety advantage: other fish can't see inside from a distance. And looking down from above doesn't suit the anatomy of a fish's eye (they see sideways, and the eyeball doesn't really move). The parents can also guard their brood better with a wide field of view around them. Because when the pot is on its side, troublemakers can hide behind it.

Photo by Jim Cumming.