The deep ocean is the closest thing Earth has to an alien world, a place where sunlight never reaches and pressure is strong enough to crush steel. It is here that some of the strangest creatures on the planet live, and thanks to submersible cameras and decades of exploration, we have finally seen a few of them in action. Others are so rare that the only evidence they exist at all is a handful of old scientific drawings, captured during brief encounters long before modern technology could follow them back into the dark.
Barreleye fish (Macropinna microstoma) – Clearly filmed by MBARI in 2009 in the Monterey Submarine Canyon.
Giant siphonophore – Documented by deep‑sea ROVs off Western Australia, most notably during a 2020 Schmidt Ocean Institute expedition.
Magnapinna (bigfin squid) – First recognised from ROV footage in the Gulf of Mexico in 1998.
Gulper eel – Originally known from 19th‑century scientific drawings based on trawled deep‑sea specimens.
Faceless cusk eel – First described in 1870 from the Coral Sea, rediscovered and photographed off Australia in 2017.
Dumbo octopus – Filmed by NOAA submersibles at depths over 3,000 metres in multiple Pacific expeditions.
Goblin shark – First documented in Japan in 1898 after a rare specimen was brought up by fishermen.
Giant oarfish – Known mostly from old illustrations until modern strandings and occasional shallow‑water sightings confirmed its form.
Phantom jelly (Stygiomedusa gigantea) – Filmed extremely rarely, first captured by deep‑sea ROV in 1899 specimen then seen alive by MBARI in 2003.
Frilled shark – Described from trawled specimens in the late 1800s, rarely filmed alive near Japan in 2007.
Black seadevil (anglerfish) – First documented from trawl captures; famously filmed alive for the first time by MBARI in 2014.
Until new generations of deep‑sea robots can spend more time at extreme depths, the ocean will continue to keep many of its secrets. For now, the strangest creatures caught on camera are only the beginning, and the sketches left behind by early explorers remind us just how much of this hidden world we still have never seen.
