Sazima, I. and Moura, R.L. (2000) Shark (Carcharhinus perezi), Cleaned by the Goby (Elacatinus randalli), at Fernando de Noronha Archipelago, Western South Atlantic. Copeia, 2000, 297-299.
https://doi.org/10.1643/0045-8511(2000)2000[0297:SCPCBT]2.0.CO;2

has been cited by the following article:

• 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.