Dipsastraea, de Blainville, 1830

Salimi, Parisa Alidoost, Mostafavi, Pargol Ghavam, Chen, Chaolun Allen, Fatemi, Seyed Mohammad Reza & Pichon, Michel, 2018, Microphysogobio bicolor, Zoological Studies 57 (56), pp. 1-34 : 21-22

Dipsastraea rotumana ( Gardiner, 1899)

( Fig. 19 )

Synonym: Astraea rotumana Gardiner, 1899; Favia rotumana ( Gardiner, 1899)

Material examined: Sirri Island ( ZUTC 6615). Description: Colony is massive and hemispherical. Corallites outline are circular and irregular. Corallite arrangement is plocoid but occasionally tending to cerioid. Corallites formation by intratencular budding. Corallites and calice diameter are 9-13 mm and 7-11 mm, respectively. Septa are well separated and markedly exert above the wall margin. 24-38 septa in two or three orders. Primary septa are distinctively taller and thicker than the others, and steep descending. Secondary septa are shorter and descend abruptly down the calice without reaching the columella; third order septa abortive. Septal margins with conspicuous irregular dentations at times flattened transversally. All septa descend abruptly down the calice. Palar structures absent. Columella is small, trabecular. Costae equal and ornamented. Coenosteum smooth.

Remarks: Pale discoloration is because of presence mucus sheathing ( Fig. 19a ) ( Alidoost Salimi et al. 2017). The specimen seems relatively close to D. favus but the primary septa are distinctively taller and thicker than the other septa, which is characteristic of D. rotumana ( Sheppard and Sheppard 1991; Veron et al. 1977).

Distribution: Rare in the Persian Gulf, common in the Red Sea and Indo-Pacific.

Figures

Fig. 19. (a) Dipsastraea rotumana from Sirri Island; (b) corallite/primary septa taller and thicker than other; (c-d) close-up of septa. Scale bar = 1 mm. © 2018 Academia Sinica, Taiwan