The massive gilltail replaced its ancestor in the deeper waters of Jujubee. Due to abyssal gigantism, they have grown to be 10x larger than their ancestors. They feed on the other inhabitants of the zone. Like their ancestor they have bioluminescent spots along their tails. They use these to communicate with each other when hunting. They also use it for mating displays. They will lay their eggs at the bottom of the sea. The offspring work their way up as they get older. Thus younger packs are near the floor while older packs are in the abyssal zone.