Rhizopsammia annae (van der Horst, 1933)

Filander, Zoleka N., Kitahara, Marcelo V., Cairns, Stephen D., Sink, Kerry J. & Lombard, Amanda T., 2021, Azooxanthellate Scleractinia (Cnidaria, Anthozoa) from South Africa, ZooKeys 1066, pp. 1-198 : 1

Rhizopsammia annae (van der Horst, 1933)

Fig. 10I, J

Balanophyllia annae van der Horst, 1933: 156-158, pl. 7, fig. 1-4. -van der Horst 1938, pl. 5, fig. 1. - Boshoff 1981: 40.

Rhizopsammia annae . -Zibrowuis and Gili 1990: 44. - Cairns and Keller 1993: 276, fig. 13C. - Cairns 2001: 27.

Type locality.

Oudekraal, Cape Peninsula, South Africa; depth unknown (van der Horst 1938).

Type material.

Unknown.

Material examined.

ORI_EIg3 (10 specimens), SAMC_A072994 (3 specimens): Locality data unknown. SAMC_A073016 (3 specimens): Eastern margin, 31 km from Richards Bay / 46 km Mlalazi Estuary, 29°00'54.00"S, 32°15'35.99"E; 500 m. SAM_H1497 (1 specimen): Southern margin, 3 km from Agulhas/ 16 km off De Mond-Heuningnes Estuary, 34°49'52.54"S, 20°00'49.88"E; depth unknown. SAM_H1498 (1 specimen):): Southern margin, 3 km from Agulhas/ 16 km off De Mond-Heuningnes Estuary, 34°49'52.54"S, 20°00'49.88"E; depth unknown. SAM_H3041 (6 specimens): Southern margin, 2 km from Mosselbaai / 10 km off Hartenbos Estuary, 34°10'37.57"S, 22°09'19.14"E; 55 m . SAM_H3366 (6 specimens): Southern margin, 15 km from Port Elizabeth / 16 km off Bakens River Estuary, 33°49'59.99"S, 25°40'00.00"E ; depth unknown.

Imagery data.

UCTES_FAL 368 L (3 specimens): Southern margin, 19 km from Pringle Bay/16 km off Buffels Oos Estuary, 34°12'36.00"S, 18°46'41.99"E; 40 m. UCTES_SCD 268 F (5 specimens): Southern margin, 6 km from East London/4 km off Buffalo Estuary, 33°02'30.00"S, 27°56'30.00"E; 55 m.

Description.

Reptoid colonies formed by ceratoid to cylindrical, straight to slightly curved corallites attached through a pedicel that expands into a thin encrusting base. Corallites united by narrow basal stolons. Calice circular to slightly elliptical (GCD:LCD = 1.0-1.2), calicular margin lanceted. Largest specimen examined (SAM_H1497) 6.3 × 5.3 mm in CD, and 13.4 mm in H. Epitheca variable in development: in some corallites epitheca reaches calicular margin, but in other corallites it is restricted to base. Costae conspicuous below theca, being equal in width and covered with fine, pointed, and randomly arranged granules. Intercostal striae porous and thin. Corallum white.

Septa hexamerally arranged in four cycles according to the formula: S1 ≥ S2> S4> S3 (≤ 48 septa). S1-2 independent. S1 most exsert, extending to columella with dentate axial margins. S2 slightly less exsert, sometimes slightly less wide, but otherwise similar in profile as S1. Higher cycle septa (S3-4) progressively less exsert, if at all. S3 is 1/3 the width of S2, with straight to slightly sinuous axial margins. S4 ¾ wider than S3, merging towards flanked S3 and again in front of S2 before joining columella as one septum. S4 axial margins the most dentate (but with fewer teeth). Septa commonly closely packed, with all septal faces being granular. Fossa of moderate depth, containing a spongy columella.

Distribution.

Regional: Southern and eastern margin of South Africa, from Pringle Bay extending towards Richards Bay; 40-500 m. Elsewhere: Only known from South Africa.

Remarks.

As noted by previous authors (van der Horst 1922; Cairns 1994; Cairns and Zibrowius 1997), a damaged Rhizopsammia specimen may be confused with Balanophyllia as it is the intact stolons that distinguish Rhizopsammia from other dendrophylliids. Nonetheless, the examined specimens agree with van der Horst’s (1922) description of the species, apart from a couple of specimens (i.e., SAMC_A072994) that followed a divergent septa arrangement according to: S1> S3> S2> S4.

Figures

Figure 10. A, B Heteropsammia cochlea (ORI _ EIe 1, locality data unknown) A calicular view B lateral view C, D Heteropsammia eupsammides (ZMK, locality data unknown) C calicular view D calicular view E-H Pourtalopsammia togata E, F (SAM _ H 2829, off East London, 146 - 238 m) E calicular view F lateral view G, H (SAM _ H 2831, off Cintsa, 159 m) G calicular view H lateral view I, J Rhizopsammia annae (SAM _ H 1497, off the Agulhas, depth unknown) I calicular view J lateral view K, L Rhizopsammia compacta (SAMC _ A 073041, off Kosi Bay Estuary, 69 m) K calicular view L lateral view M, N Rhizopsammia verrilli (SAM _ H 1502, off Richards Bay, 165 m) M calicular view N lateral view O Tubastraea coccinea (ORI _ EIb 4, Isipingo; depth unknown) P Tubastraea sp. cf. Tubastraea diaphana (SAM _ H 5103, Cape Vidal, 59 m): Calicular view. Scale bars: 10 mm.