by Aaron G. Filler, MD, PhD
A-1 – A peristaltic wave moves backward from segment to segment as the animal moves forward - segments maintain their total volume. A-2 – A peristaltic wave moves forward as the animal moves forward – segments change their volume – fluid is pumped from one segment to the next.
B-1 – Limbs on Artemia – the brine shrimp with waves progressing in phase on right and left side.
B-2 – Comb plates in overlapping shingle formation along the body of the jelly fish Pleurobranchia.
B-3 – A polychaete worm (Phylum Annelida) Nereis can use its “parapodia” (feet) to walk or to swim by mixing different types of metachronic waves.
C – Alternating tripod locomotion in an insect.
A – Redrawn, modified afer: Elder, H. Y. (1980). Peristaltic mechanisms. Aspects of Animal Movement. H. Y. Elder and E. R. Trueman. Cambridge England; New York, Cambridge University Press: 71-92.
B - Redrawn, modified after: Sleigh, M. A. and D. I. Barlow (1980). Metachronism and control of locomotion in animals with many propulsive structures. Aspects of Animal Movement. H. Y. Elder and E. R. Trueman. Cambridge England ; New York, Cambridge University Press: 49-70.
C – Redrawn, modifed after: Dickinson, M. H., C. T. Farley, R. J. Full, et al. (2000). How animals move: an integrative view. Science 288(5463): 100-6.