Cave Finworm

The cave finworm split from its ancestor the carnivorous sea finworm. It is very much like its ancestor except it has adapted to cave environment. It eats most of the smaller creatures in the cave and has adapted larger compound eyes for seeing in the low light. The most drastic feature is that it has developed primitive gills so it can say underwater fill time now. However if it swims too fast it might go through its oxygen too fast before the gills can filter it and must gulp air fro the surface or risk passing out.