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 : 818

Acropora digitifera (Dana, 1846)

Fig. 9

Colony growth form: Digitate with little ramifications at the base of branches.

Axial corallites: Outer diameter 2.7 mm; inner diameter 0.9 mm; conspicuous, tubular with thick wall and round opening; first and second septal cycles are well developed and usually not dentate.

Radial corallites: Dimidiate, upper wall is absent and lower wall is thickened and flaring; they are uniform and usually arranged in rows; radials are numerous but not touching; primary septa are present and second cycle is reduced or incomplete.

Coenosteum: Densely arranged line of elaborated spinules on corallites, may resemble costae on longer corallites; between corallites, coenosteum is reticulate with elaborated spinules.

Remarks: Species of the A. humilis group are closely related and very similar in growth form and other characters ( Veron & Wallace 1984). We distinguished A. digitifera from others by its thinner branches, its radials corallites with a characteristically flaring outer lip and the absence of an upper wall, which gives them a sharp appearance, as noted by ( Veron 2000).

Figures

Fig. 9. Acropora digitifera. Specimen number: VAM29. (A) live colony; (B) branch fragment; (C) radial corallites; (D) branch fragment; (E) axial corallite; (F) coenosteum between corallites.