Abyssal Nautilus

The spiral-shelled Abyssal Nautilus, in the various stages of their life cycle, are key participants in the food web of the deep ocean, both as predators and prey. Well armored and enthusiastically carnivorous, they will happily eat anything smaller than them (including smaller nautilus.) They are agile in the water, but also slow moving, and for creatures that can pierce their shells or otherwise disable or overpower them, they make a tasty meal. Most notably, as adults, their shells are used as homes for the most elusive inhabitant of the Brunivard deeps, the Hermit Kraken.
Abyssal Nautilus are sexually mature in their second year. They are hermaphrodites (any individual nautilus can be both father and mother.) They reproduce sexually. During the spring and summer, when two nautilus of around the same size meet, they will exchange packets of genetic material. These packets may be eaten, but are usually stored in the reproductive organs to fertilize eggs. In the fall, the nautilus produce eggs. Rather than lay them in the environment, clutches of nautilus eggs mature inside the chambered shell of their parent. At hatching, the first meal of the young nautilus are its clutch mates, but when the survivors start trying to eat the flesh of their enclosure, they are dumped unceremoniously into the ocean to make their way in the world. Their shells, and the darkness of the deep water, protect them as they grow. The first clutches of a yearling nautilus may only produce one or two surviving offspring. The great old nautilus of the deeps can produce thousands of offspring in a clutch.
The Abyssal Nautilus range covers nearly all of the oceans of Brunivard. They range from 10cm at hatching to 10m for the oldest and scariest monsters of the deep.