Tell-tail Adaptations for Respiration and Rapid Escape in a Freshwater Oligochaete (Lumbriculus variegatus Mull.)

The aquatic oligochaete, Lumbrimlus variegatus (Order Lumbriculida; Family Lumbriculidae), utilizes a combination of postural and anatomical specializations that enhance gas exchange across the dorsal surface of posterior segments as these segments lay exposed at the air-water interface. Predator avoidance by exposed posterior segments is enhanced by neurobehavioral mechanisms involving a well-developed lateral giant nerve fiber system that mediates rapid escape withdrawal of the worm's tail in response to shadow or mechanosensory stimuli.