YOUNG JUSTICE (2010-2012)
The version of Kaldur in the YOUNG JUSTICE universe differs slightly from his comic-book counterpart. Instead of being raised in secret in New Mexico by human parents, Kaldur was raised in Atlantis where he was trained to fight and hone his skills.
He was chosen by Aquaman himself to become his protege, journeying to the surface and taking on the codename Aqualad as he trained to become a Super Hero. During his training, he met Dick Grayson and Wally West, who he eventually came to know as teammates. The trio formed Young Justice and began acting as a sort of junior-level Justice League under the watchful eyes of their mentors, rapidly expanding their ranks and testing their abilities. Kaldur, thanks to his level head and quick decision making, was named the team's first official leader.
Following the five year time jump between seasons one and two, Kaldur was revealed to have "betrayed" the team and gone to work with the man he learned to be his real father: Black Manta. In truth, Kaldur had gone to work with Manta was part of a deep cover mission known only to his closest friends as the team worked to bring down a mysterious cabal of unknown enemies known only as The Light.
The reality of Kaldur's position and allegiance were eventually made clear and the Light -- along with their partner, The Reach -- were defeated, but not until Wally West, one of Kaldur's close friends and original teammates, sacrificed himself.
Despite this tragedy, Kaldur remained with the team and will be returning in the upcoming third season of YOUNG JUSTICE.
Modern Comics (2010-Present)
Following his introduction in 2010, teenager Jackson Hyde was revealed to have been instilled with a massive fear of water by his adoptive parents. It was later revealed that this fear had been born of their desire to keep Atlantean parents from locating him -- or, rather, the Atlanteans hired by his true father, Black Manta. Once Jackson learned the truth, he was almost immediately pulled into the events of 2010-2011's BRIGHTEST DAY, when he learned to use his innate, water-based abilities to help defend his adopted parents from Manta and his squad of hunters lead by Siren.
During the conflict, Jackson met Aquaman for the first time, which serves to uncover more of his past. Jackson was given a set of armor and weapons, known as "Water Bearers" to help control his abilities, by Mera, which he used to fend of the persistent attacks of Manta and Siren.
After having proven himself more than capable in the fight, Aquaman decided Jackson's best course of action would be to join the Teen Titans (BRIGHTEST DAY, 2010-2011).
An updated incarnation of Jackson was introduced in DC UNIVERSE REBIRTH #1 (2016), which established him as young boy who had only just begun to realize his abilities. This version of Jackson did end up joining the Teen Titans under the leadership of Damian Wayne, the current Robin, after spending some time trying to learn to control his hydrokinetic powers on his own. Unfortunately, joining the Teen Titans also alerted his father, Black Manta, to his existence (TEEN TITANS #7, 2016).
Jackson remained with the team until they were evicted from their base of operations in 2017's TEEN TITANS #17.