Mizudako (North pacific giant octopus) is a huge octopus that grows to 3 meters long and lives in cold region waters. While Madako is distributed already boiled, Mizukako is often distributed raw.
It has been more consumed as domestic ingredient instead of madako which has been disappearing from sushi counter due to its declining fish haul. Mizudako has a bit watery flesh but tender and really delicious eaten with shari. Many sushi chefs believe that citrus and salt go with Mizudako better than soy sauce.
List of Squid (Ika) and Octopus (Tako)
Hokkaido Aomori Miyagi