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 : 827-829

Acropora intermedia (Brook, 1891)

Fig. 18

Colony growth form: Indeterminate arborescent with thick cylindrical branches that may be straight or contorted.

Axial corallites: Outer diameter 2.2–2.4 mm; inner diameter 0.8–0.9 mm; long and tubular; primary septa are well developed and secondary septa may be present or not, sometimes incomplete; margin of septa is rather smooth.

Radial corallites: They are of two types, tubular with oval to strongly dimidiate opening interspersed with sub-immersed corallites; longer ones have two cycles of small dentate septa (which may be incomplete on those with very dimidiate opening), while septa on shorter ones may be absent or only visible as points; radials generally have a sharpedged lower lip, giving colonies a rasp-like appearance.

Coenosteum: Costate on corallites and reticulate with scattered spinules in intercorallite areas.

Remarks: This species has longer, thinner branches than other species of the Acopora robusta group. We distinguished it from other staghorns, with which it shares the general appearance, by its highly calcified corallum giving robust branches as well as the dissimilar structure of radial corallites. At Vamizi, live colonies of A. intermedia consistently produced large amounts mucus and were very slimy to the touch during collection.

Figures

Fig. 18. Acropora intermedia. Specimen number:VAM41. (A) live colony with (B) branch fragment; (C) axial corallite; (D, E) portion of branch showing radial corallites.