The new cephalopod, also named Paul in honour of his world-famous predecessor who passed away last week, was lowered gently into his tank in a ceremony carried live on national television.
Paul the younger initially appeared more publicity-shy than his media-hungry forerunner, sticking closely to the side walls of the tank as the TV cameras rolled.
The aquarium in Oberhausen in the Ruhr Valley limited the number of photographers allowed into the room, amid hefty interest from around the world.
"We got him from near Montpellier" in southern France, an aquarium employee told news agency AFP.
However, the German aquarium was keen to downplay the possibility that Paul II will inflict the same pain to bookmakers as Paul I did, to the joy of punters around the world.
"No one yet knows whether Paul will be able to follow in his footsteps, or rather, his tentacle steps," aquarium spokeswoman Tanja Munzig said in a statement.
Paul I shot to fame by defying the odds to predict eight successive games during the recent World Cup in South Africa, including Spain's 1-0 triumph against the Netherlands in the final.
For the prediction, two boxes were lowered into the salty soothsayer's tank, each containing a mussel and the flag of the two opposing teams.
Watched by a myriad of reporters, Paul would head to one box, wrench open the lid and gobble the tasty morsel, with the box he plumped for being deemed the likely winner.
His astonishing ability made him a global media phenomenon. His later predictions were carried live on rolling news channels in Germany.
He died peacefully in his sleep aged nearly three on October 26, sparking hundreds of messages of condolence from his 60,000-strong Facebook fan club and some less serious comments.
“Paul the octopus is dead. Bet he didn't see that coming," wrote several users on microblogging site Twitter.
It is unlikely, however, that around five-month-old Paul II will live to give predictions for the next World Cup in 2014 in Brazil, given that the life expectancy of octopuses in captivity is around three years.
Whether he will make the next European championship, in Ukraine and Poland in 2012, is also far from being a safe bet.