Twilight Nipper
The twilight nipper diverges from the vellicator by following the twilight gill to higher levels of the ocean. They continue to hone their feeding strategy of nipping off a chunk of their prey and darting away with it. Indeed, they prefer to keep their prey alive so they can return and feed from the same individual; a vellicator will often follow a twilight gill for days of persistent harassment. This strategy has led to a further reduction in size as well, making it easier to sustain themselves without killing as quickly. When multiple twilight nippers find the same prey, however, they are liable to swarm together and bring it down en masse; although they will cooperate during the swarm, they will usually squabble with each other over the scraps afterwards.
They mostly specialize in twilight gills, with their nutrient-rich gills, and which are large enough to survive multiple attacks. But they supplement their diet as well. They frequently found themselves eating vampire litusfoi along with gill chunks. With their concentrations of blood, these were especially delectable targets, so the twilight nipper has adapted to spot these parasites and eat infected areas by preference. Twilight nippers also occasionally chomp on other soft-bodied prey like Carpolantaians or cish.
Their hunting strategy relies on both persistence swimming and quick bursts of speed, the former to trail the prey and the latter to grab their food, rip it off, and get away. Persistence is their usual mode, and they retain the ancestral lunate tail and gills that require constant swimming. But, as in the vellicator, they also store oxygen in their blood, which they now use exclusively to release quick energy boosts when needed.
Like before, they have three rigid rings of chitin that support paired fins and a dorsal fin. These have grown, protecting more of the body, while leaving exposed areas in between where they can bend more flexibly. The tail remains less covered, however, as they need increased flexibility there. They also retain the three notochords for internal support.
Their feeding tentacles can lock together to form a tapered shape, where barbs on one side fit together with pits on their opposite counterpart. The longest barbs have developed to extend and retract, pointing outward when in use, providing an array of sharp, shearing, and gripping equipment to tear food away. They have no real ability to chew, though, and must swallow the chunks whole, so they must remove chunks that are small enough to fit in their digestive tract. The mouth tentacles also contain electroreceptors to help them hunt, though they are increasingly reliant on sight.