pelagic stems from Ancient Greek (pélagos), meaning ‘open sea
the pelagic zone can extend to 5 vertical regions in the ocean:
- Epipelagic Zone (sunlight) - epi- meaning upon, above, or in addition
- Mesopelagic Zone (twilight) - meso- meaning middle
- Bathypelagic Zone (midnight) - the name stems from Ancient Greek βαθύς, meaning ‘deep’.
- Abyssopelagic Zone (lower midnight) - the name is derived from Ancient Greek ἄβυσσος, meaning ‘bottomless’ (a holdover from the times when the deep ocean, or abyss, was believed to be bottomless)
- Hadopelagic Zone - the name is derived from the realm of Hades, the Greek underworld