Using computed-tomography to document borings by Osedax mucofloris in whale bone

Chemosynthesis-based communities have existed on whale skeletons for over 35 million years. However little is known about the effects of Osedax boring on the bone taphonomy and ecology of the whale-fall community. In order to evaluate this important process we used micro computed-tomography (CT) to ascertain the morphology of borings produced by Osedax mucofloris on a Minke whale bone exposed on the sea-floor for eight months. CT images revealed wide, shallow sub-surface cavities where the roots eroded the bone. These cavities were restricted to the densest layer of bone and had a maximum penetration of 2.63 mm. Over the eight month period 0.67% of the bone had been degraded directly by Osedax borings. These findings suggest that the presence of Osedax can lead to the rapid degradation of whale bones, having important implications for the ecology of whale-fall communities. Furthermore, these descriptions allow the potential identification of Osedax activity at fossil whale-falls.