The Mackeral (Versace/Dean)

The mackeral swims lateral from side to side you see
It rarely perpendiculates and ambles vertically
In the mostly horizontal plane it lives exclusively
Except of course in times of stress or dire emergency

It's soberingly stupid and has not much creativity
The turn to face straight up or down needs cognative agility
So solely on the level does this fish persist to be
A credit to the science of ictheology