Fig. 2. Confocal images of a transverse slice (1 mm) of freeze-substituted Galaxea fascicularis showing (A) oral ectoderm (OE) and oral gastrodermis (OG) separated by mesogloea (M). In the OE, non-specialised ectoderm cells (E), mucocytes (Mu) and cnidocytes (Cn) are easily identified. The OG comprises non-specialised gastrodermis cells (G), mucocytes and zooxanthellae (Z). (B) The aboral epithelia consist of the aboral gastrodermis (AG), which is separated from the calicoblastic ectoderm (CE). Few zooxanthellae are present in the aboral gastrodermis and the epithelium consists primarily of mucocytes and non-specialised gastrodermis cells. The calicoblastic ectoderm consists of thin elongated cells containing numerous vesicles. Mucocytes are occasionally present. SK, skeleton.