Leviathan (Orion's Arm)

Leviathans are large, non-sapient animals native to New Poseidon in the Orion's Arm universe.

Biology
A Leviathan has a tubular body, open at both ends, measuring 100 meters long and 20 meters wide in adulthood. It locomotes itself by propelling water that gets inside of its body, and feeds off the microorganisms in the process. On its homeworld of New Poseidon, it fills a role in the food chain that is analogous to that of whales on Earth.

Locomotion is assisted by 6 fins, and although it has 12 eyes, Leviathans prefer sonar to perceive their environment.

Behavior
Leviathans travel in small families of 3 to 7 individuals. When the number of individuals surpasses that range, they split off into pairs.