Rhombopsammia niphada Owens, 1986

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

Rhombopsammia niphada Owens, 1986

Fig. 14E, F

Rhombopsammia niphada Owens, 1986a: 252-255, figs 2B, 3A-D. - Cairns 1989a: 19-20, text-fig. 2, pl. 9, figs D-I, pl. 10, figs A, B. -Cairns 1994: 41, pl. 15, figs I-K, pl. 16, figs A, B. -Owens 1994: 588. - Cairns and Zibrowius 1997: 75-76. - Cairns 1998: 371. - Cairns et al. 1999: 34. -Plusquellec et al. 1999: 998. -Cairns 2004a: 271. - Cairns 2009: 2. - Kitahara et al. 2010b. -Janiszewska et al. 2011. - Quattrini et al. 2020: 1538, fig. 1. -Seilitz et al. 2020: 11. - Kitahara and Cairns 2021: 64-65, 67, figs 15D, H, 18, 19A-D.

Type locality.

Off Kyushu (USS ‘Albatross’ stn. 4911: 31°38'00"N, 129°19'00"E); 715 m (Owens 1986a; Cairns 1989a).

Type material.

Types are deposited at the NMNH ( Cairns 1989a).

Material examined.

SAM_H1390 (1 specimen): Southern margin, 28 km from Port Alfred / 3 km off Old Woman’s Estuary, 33°30'00.00"S, 27°08'59.99"E; 90 m. SAM_H1453 (3 specimens): Southern margin, 6 km from Kidds Beach / 5 km off Ncera Estuary, 33°11'59.99"S, 27°40'59.99"E; 79 m. SAM_H3126 (2 specimens): Southern margin, 15 km from Port Alfred / 11 km off Riet Estuary, 33°39'18.00"S, 27°01'05.99"E; 90 m. SAM_H3128 (1 specimen): 15 km from Port Alfred / 11 km off Riet Estuary, 33°39'18.00"S, 27°01'36.00"E; 90 m.

Description.

Corallum discoidal (GCD:H = 3.1-3.9), with a flat to slightly concave or convex base. Septa imperforate, solid, and dentate. Largest specimen examined (SAM_H1453) 22.7 mm in CD and 5.8 mm in H. Calice circular, with finely serrated edges. Costae ridged and thin, with closely packed low profile granules resulting in serrated costae. Costal bifurcation alternates with septal pattern. Intercostal spaces porous, broader than costae, decreasing towards epicentre of base. Synapticular bars connect two costae to common adjacent septum, resulting in pores that also decrease in size towards epicentre of base. Septa gradually slope towards calicular margin, producing a narrow marginal shelf, which reaches a maximum of 2 mm. Corallum white.

Septa arranged in typical micrabaciid fashion, with ≤ 144 septa. S1-2 non-bifurcate and straight, with subsequent S3 leading to multiple bifurcations. S1 extend to columella with complex and uniform dentitions along septal margin, and bearing vertical vepreculae on lateral faces. S2 also straight and extending to columella, but joined by S3 near columella. Resulting S2-3 fusion forming a delta with numerous spines. S3 bifurcates repeatedly. First bifurcation produces two S3i on either side of S2. Resultant edges of S3i adjacent to S2 bifurcates three more times in which the first branching gives S3ii, second one S3iii, and last gives two S3iv. S3i adjacent to S1 bifurcates six times, in which the first gives two S3iii, three S3iv, and two S3iv. All septa are predominantly solid, with S3 being perforated at base and at bifurcations. Axial edge of S1-2 and sometimes S3, join the spongy columella.

Distribution.

Regional: Southern margin of South Africa, off Port Alfred extending towards Kidds Beach; 79-90 m. Elsewhere: Philippines; Indonesia ( Cairns 1989a; Cairns and Zibrowius 1997); Japan (Owens 1986a); 424-852 m.

Remarks.

The material examined herein represents a new record of Rhombopsammia niphada for South Africa, but adds no taxonomic information to what is already known about the species’ morphology. Rhombopsammia niphada may be mistaken for Letepsammia formosissima , which is also found in South Africa, but differs in having predominantly solid septa, and in S1 septal faces bearing vepreculae, as compare with porous septa and smooth S1 septal faces in L. formosissima ( Cairns 1989a; Cairns and Zibrowius 1997).

Figures

Figure 14. A, B. Letepsammia formosissima (SAM _ H 1429, off Kidds Beach, 79 m) A calicular view B basal view C, D Letepsammia franki (SAMC _ A 090070, off Durban, 95 m) C calicular view D basal view E, F Rhombopsammia niphada (SAM _ H 1390, off Port Alfred, 90 m) E calicular view F basal view G, H Stephanophyllia fungulus (SAMC _ A 073106, Cape Vidal, 140 m) G calicular view H basal view I Madrepora oculata (SAM _ H 3038, off St Lucia, 825 m) full view J, L Culicia sp. cf. Culicia australiensis (SAMC _ A 073032, off Shaka's Rock, 50 m) J calicular view K full view L septa details M, N Culicia excavata. M (UCTES _ DBN 85 H, off Ispongo, depth unknown): full view N (BMNH 1840.09.30.19, Cape of Good Hope, depth unknown): Calicular view O, P Stenocyathus vermiformis (SAM _ H 3213, off Cintsa, 630 m) O calicular view P lateral view Scale bars: 10 mm (A-H, J-N); 100 mm (I); 2 mm (O, P).