Acropora, Oken, 1815

Sola, Erwan, Silva, Isabel Marques da & Glassom, David, 2015, An annotated and illustrated checklist of species of the coral genus Acropora (Cnidaria: Scleractinia) from Vamizi Island, Mozambique, African Invertebrates 56 (3), pp. 807-807 : 812-813

Acropora cf. appressa (Ehrenberg, 1834) (Riegl 1995 as A. sordiensis)

Fig. 3

Colony growth form: Caespito-corymbose; branches are irregularly anastomosed and taper slightly. Incipient axial corallites are common distally on branch.

Axial corallites: Outer diameter 2.9 mm; inner diameter 1.0 mm; prominent, dome-shaped to conical with small round opening; clearly, two septal cycles are well developed and a third cycle may be visible.

Radial corallites: Irregularly sized and arranged, appressed tubular with round to oblique opening; the most appressed ones have a reduced inner wall and those with oblique opening are usually hooked upward; towards the base of branches, radials are generally absent or sub-immersed to immersed; two cycles of dentate septa, directives are usually prominent.

Coenosteum: Dense arrangement of laterally flattened spinules with elaborated tips throughout.

Remarks: At locations like Madagascar, the Seychelles and Tanzania, this species usually has longer and more conical axial corallites (see Veron 2000). Our specimen, however, is more consistent with those described in Riegl (1995) (as A. sordiensis), owing to the similar growth form, the characteristics of radial corallites with some having a hooked lip, and the structure of the coenosteum, which consists of an arrangement of elaborated spinules.

Figures

Fig. 3. Acropora cf. appressa. Specimen number: VAM68. (A) live colony; (B) branch detail; (C) radial corallites; (D) axial corallite; (E) coenosteum between corallites.