Sometimes this can be accomplished by gently squeezing the body. Ambulacra The five ambulacra of are marked externally by five longitudinal rows of small, inconspicuous tube feet . The areas between the ambulacra are the interambulacra . The longitudinal body wall muscles of cucumbers do not occur in a continuous sheet rather are in five strong longitudinal muscle bands. These bands are ambulacral in position and can sometimes be seen externally.
Most cucumbers creep over the surface of the substratum or burrow into it.
One species swims. When creeping they keep the ventral surface in contact with the bottom and this surface is specialized for the purpose. The flat ventral surface has better developed tube feet, which are known as locomotory podia. The two dorsal ambulacra are the bivium . Similarly, the interambulacra are dorsal, right dorsal, left dorsal, right ventral, and left ventral.