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 : 831

Acropora microphthalma (Verrill, 1869)

Fig. 21

Colony growth form: Small staghorn with arborescent growth pattern; branches are slender and frequently divide such that compact thickets may be formed.

Axial corallites: Outer diameter 2.3–2.8 mm; inner diameter 0.9–1.0 mm; tubular and short; primary septa are well developed and second cycle may be present or incomplete. Radial corallites: Small and numerous, generally similar and aligned in rows; they are tubular to tubo-nariform towards branch tip with round or oval opening; dentate primary septa are present and rudimentary or incomplete second cycle may develop.

Coenosteum: On corallites, dense arrangement of laterally flattened elaborated spinules forming neat lines; between corallites spinules with elaborated tips are less densely arranged.

Remarks: Despite some resemblance with other staghorn corals, especially A. muricata (Linnaeus, 1758), colonies of A. microphthalma have more slender branches and radial corallites that are tubular but not appressed (see Wallace 1999). Furthermore, the coenosteum of our specimens consists of a dense arrangement of spinules with very elaborate tips, a characteristic of well developed colonies of A. microphthalma ( Wallace 1999; B. Riegl pers. comm.)

Figures

Fig. 21. Acropora microphthalma. Specimen number: (A, B, D–F) VAM21; (C) VAM14.(A) live colony; (B) branch fragment; (C, D) axial corallite; (E) radial corallites; (F) coenosteum between corallites.