Squids of the  Calidocene

In the Calidocene Epoch, squids have diversified rapidly in the southern hemisphere. Most squids in the Calidocene are descended from the Antarctic Flying Squid. Unlike many species, the Antarctic Flying Squid was able to tolerate the horrendous conditions of the Holocene extinction and bounce right back. 

Krakens

Krakens (Navisruptor Euroni) are a monotypic genus found in the Southern hemisphere's ocean gyres. They grow to at least 4 feet long and live for 2-3 years. Krakens are primarily prey for porphins, other Krakens, and large fish. Parasites are drawn to Krakens, which caused Krakens to ally with cleaner fish, which accidentally make the large squid vulnerable to predation.

Like the Kraken myths of the past, Krakens drag watercraft under the sea. A Kraken will wrap its arms around a small stormraft and use its jets to pull it under the sea. The waterlogged stormraft will be ripped apart and the squid will grab everything it can eat with its tentacles before letting the raft float back to the surface. 

Riverdyers

With the slow desalinization of the Southern Ocean during the late Holocene and following extinction, local squid were forced into adapting to lower salinities, moving away, or dying. One such branch went through endless amounts of trial and error to perfect the ability to live in fresh and brackish water. Eventually, once the ice thawed out and rivers formed, the Riverdyers (genus fluviololligo) rose to prominance in the rivers and brackish waters of Antarctica. 

Riverdyers are about a foot and a half long in length. Their skin changes depending on the color of their surroundings. Riverdyers hunt in packs of about 3-4. Half of the pack will encircle a school of fish with ink clouds while the other half will slaughter any fish that get caught up in the circle.

Anglersquid

Unlike the Riverdyers that embraced freshwater, the Anglersquids (Genus hastur) went further deep to breathe easier. They measure in at 3 feet in length and have a dark red coloration. Most live in in the upper bathypelagic but some travel into the lower bathypelagic to hunt. 

Anglersquids feed on strobefish and will often work together to do so. Pheromones will be released that breaks the strobeswarm. When the flock is scattered, the Anglersquid will slurp up any fish it can get its suckers on.