This article contains spoilers from the most recent DCEU film. You have been warned.
Prior to Steppenwolf's invasion, Atlanteans appeared to be merely a sea-faring civilization, not yet inhabiting the underwater environment of the oceans yet.
Atlanteans are generally similar to Humans in appearance; however, they are distinguished by their ability to adapt to aquatic environments, possessing a superior sensory arrangement that allows them to navigate the depths of oceans uninhabitable by Mankind. In contrast to their external similarities, Atlantean internal anatomy differs radically from that of Humans. For instance, some Atlanteans are capable of telepathically communicating with marine life.
Atlanteans possess a highly efficient respiratory system that allows them to extract oxygen from water, allowing them to breathe freely underwater as they would on land. Physical characteristics differ from Humans as well, as Atlanteans are shown to possess superhuman strength and speed that allows them to travel immense distances underwater faster than any naval vessel.
The Atlantean body structure is immensely durable, enough to withstand water pressure from at least 20,000 feet below sea level.
However, though they are capable of surviving in both environments, prolonged exposure to the surface world without access to water would weaken an Atlantean, presumably to levels similar or equal to that of a Human.
Thousands of years ago, Atlanteans joined with the forces of the Amazons and Humans to fight off an invasion of Earth by Steppenwolf and his massive Parademon army. As their battle escalated, the Olympians descended to aid, along with Yalan Gur. An ancient Atlantean king led the forces of Atlantis from their massive ships onto shore, where the Amazons and armies of Mankind had been driving back the forces of Apokolips. Zeus and Artemis greatly crippled the invaders' forces, causing Steppenwolf to retreat, much to his dismay. As they departed, the three Mother Boxes were separated by Zeus, entrusting them to the forces of Earth for safekeeping.
Years later, Lex Luthor hijacked footage from an NSA UUV drone, where Curry was spotted emerging from a decrepit sunken ship somewhere within the Tonga Trench at over 20,000 feet. The drone was shortly after destroyed by Curry with his trident, and footage from a second drone showed the Atlantean swimming away fast enough to cause a sonic boom in his wake.
Assault on Atlantis
During his return to Earth, Steppenwolf invaded the kingdom of Atlantis in his quest to reobtain and unify the Mother Boxes. There, he faced off against Mera and Aquaman, as well as a number of the Atlantean Royal Guard. Despite their attempts to combat his invasion, Steppenwolf successfully retrieved the Mother Box, escaping through a portal.
- ↑ 1.0 1.1 Goyer, David S., Terrio, Chris (writers) & Snyder, Zack (director) (March 25, 2016). Batman v Superman: Dawn of Justice.
- ↑ 2.0 2.1 Terrio, Chris, Whedon, Joss (writers) & Snyder, Zack (director) (November 17, 2017). Justice League.
- ↑ Ayer, David (writer and director) (August 5, 2016). Suicide Squad.