Fig. 7
From: Life in a tube: morphology of the ctenostome bryozoan Hypophorella expansa
Sequence of images (from a–d) taken from Additional file 1 Video S1 showing the eversion of the vestibular wall bearing the gnawing apparatus of Hypophorella expansa. The red line marks the distal border of the borehole created by the bryozoan. The pink line shows the distal border of the vestibular wall as it moves closer to the border of the borehole. Note that the gnawing apparatus is discernable by its distinct brownish appearance. Abbreviations: ds – diaphragmatic sphincter, gwa – gnawing apparatus, sbo – space balloon