Giant nerve fibers and rapid escape reflexes in newly hatched aquatic oligochaetes,Lumbriculus variegatus(Family Lumbriculidae)

Summary Cocoon production and embryonic development within cocoons are documented in the aquatic oligochaete, Lumbriculus variegatus, a species which predominantly reproduces asexually by fragmentation. Correlated electrophysiological, behavioral and histological results indicate that giant nerve fibers are present at hatching and mediate rapid escape responses to shadow and tactile stimuli. Medial and lateral giant nerve fiber conduction velocities in newly hatched worms were 4.8 and 3.0 m/s, respectively.