Ribbonswimmer

Ribbonswimmers are a species of filter-feeding, worm-like organisms native to Saturn. They are a staple prey species of Rukhs and other Saturnian predators.

Anatomy and physiology
Ribbonswimmers have long, flat bodies. While they may reach hundreds of meters in length and four meters across, they are only a few centimeters thick. Consequently, their edges are sharp enough to injure predators. They are almost completely transparent, with their only dark regions being the eyespots they use to detect light. Ribbonswimmers are composed of many hundreds of segments, each with a single mouth.

Diet
Ribbonswimmers feed on plankton in Saturn's atmosphere. They filter it out using cilia lining their bodies, then funnel it to their mouths, which are little more than open stomachs.

Reproduction and life cycle
Ribbonswimmers reproduce by fission. When they grow to an optimum size, they split in half, with each half becoming an independent organism.

Appearances

 * Saturn Rukh, by Robert L. Forward (1997)