TITLE:
Is the Shark Just Drifting, or Does It Take a Quick Nap?
AUTHORS:
Erich K. Ritter
KEYWORDS:
Drifting, Melatonin, Pineal Gland, Shark, Sleep
JOURNAL NAME:
Open Journal of Animal Sciences,
Vol.10 No.1,
December
13,
2019
ABSTRACT: It is unknown if resting sharks can sleep, which is also true for gliding ones. Here, a videotaped bull shark is presented that drifted in an uncontrolled manner for 120 seconds while sinking with 0.1 m/second. Several aspects are discussed to determine if the shown behavior reflects the commonly accepted definition of sleep. Additionally, the idea is also discussed if this state might reflect a “quiet waking state” instead of where the shark still maintained some vigilance despite its general appearance.