Sipunculid Burrows in Coral Reefs: Evidence for Chemical and Mechanical Excavation

Abstract

The crystalline structure of sipunculid burrow linings from dead
\ncoral as studied with the scanning electron microscope indicates the presence of
\netching similar to that produced by treatment of unmodified coral surfaces with
\nacid, and with EDTA. Initial biochemical activity appears to weaken intercrystalline
\nbonds, permitting detachment of crystals by mechanical abrasion and
\nsubsequent deposition of their fragments in spaces between corallite walls.