Rugose Floater

Rugose Floaters are heavily wrinkled, fish-like inhabitants of Darwin IV that float in the air. They feed on Aerophytes and Microflyers. During spawning season, they trail eggs behind their "fins" by filaments and reduce their crescent shape when spawning is complete. When threatened, they release a cloud of particles from their black eye-like appendages to fragment its sonar image, but this doesn't stop Skewers from attacking them. The Skewers do not feed on the Floater, but merely pierce it's methane-filled bags, causing the Floater to fall to its death for sport.

Trivia

 * This is the creature seen on the front cover of Expedition.