These sharks can’t breathe
Unless they’re moving.
Water isn’t
Merely soothing.
Rather, it is
Used for breathing,
Flowing over gills,
And leaving
Some of us
To stop and think,
“These Dogfish never
sleep a wink.”
“Aren’t they tired?”
You might ask.
It turns out they
Can multitask!
Because their spines
Can navigate,
These sharks don’t
Have to stay awake.
Their lives would
Certainly be grim
If Dogfish couldn’t
Sleep and swim.
SPINY DOGFISH SHARKS
Some shark species need to keep swimming forward to survive. This forward movement pushes the oxygen-rich water through their mouths and over their gills, allowing them to breathe. One might think that these sharks need to keep moving, perhaps it is impossible for them to sleep. Scientists are not sure whether all sharks sleep, but studies have shown that the Spiny Dogfish Shark navigates with his spine, which allows him to sleep off and on while swimming. When sleeping, cloudy membranes cover their open eyes.