Rhizopsammia verrilli van der Horst, 1922

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 verrilli van der Horst, 1922

Fig. 10M, N

Rhizopsammia verrilli van der Horst, 1922: 64, pl. 8: figs 1, 2. - Wells 1983: 241-242, pl. 15: figs 1-4. - Cairns 1991: 25, pl. 22, figs C-E. - Cairns and Zibrowius 1997: 188-189, fig. 28F, G. - Cairns 1998: 408. -Cairns 2004a: 318.

Balanophyllia scheeri Durham, 1962:46, 53-54, figs 2B, C, 4, 7 . - Durham 1966: 125.

Dendrophyllia gracilis . - Cairns 1991: 23.

Type locality.

Indonesia (HMS ‘Siboga’ stns. 220 and 282); 54-278 m (van der Horst 1922).

Type material.

Syntypes are deposited at the ZMA (Cairns 2004a).

Material examined.

SAMC_A073042 (8 specimens): Eastern margin, 53 km from Shaka’s Rock / 46 km off Zinkwasi Estuary, 29°32'53.88"S, 31°47'12.11"E; 200 m. SAMC_A073157 (5 specimens): Eastern margin, 10 km from Port Edward / 24 km off Bilanhlolo Estuary, 31°05'48.11"S, 30°18'47.88"E; 140 m. SAMC_A073197 (2 specimens): Eastern margin, 18 km from St. Lucia Estuary / 15 km off Mfolozi Estuary, 28°31'48.00"S, 32°26'06.00"E; 160- 180 m. SAMC_A073198 (1 specimen): Eastern margin, 10 km from Shaka’s Rock / 12 km off Mhlali Estuary, 29°32'12.00"S, 31°19'47.99"E; 50 m. SAM_H1502 (1 specimen): Eastern margin, 14 km from Richards Bay / 23 km off Mlalazi Estuary, 28°52'59.99"S, 32°01'00.00"E; 165 m.

Description.

Colony consists of corallites interconnected by narrow stolons, and composed of small corallites budding from upper margin zone of larger corallites. Corallites ceratoid to cylindrical. Largest examined corallite (SAMC_ A073198) 9.3 × 8.8 mm in CD, and 21.5 mm in H. Epitheca thin, if present. Costae granular, conspicuous throughout corallum, and equal in width. Intercostal striae thin, porous. Corallum white.

Septa hexamerally arranged in four cycles according to the formula: S1 > S2 ≥ S4 > S3 (48 septa). S1-2 independent, most exsert, and joining columella deeper in fossa with straight axial margins. S2 slightly less wide than S1. Higher cycle septa (S3-4) progressively less exsert. S31/3 the width of S2, and bear laciniate axial margins. In complete half-systems a pair of S4 meets before S3 and joins columella as one septum. S4 axial margins dentate to laciniate. Septa appearing loosely packed, with all septal faces covered with granules. Pali absent. Fossa of moderate depth, containing a spongy columella.

Distribution.

Regional: Eastern margin of South Africa, extending from off Port Edward towards St Lucia; 50-200 m. Elsewhere: Philippines ( Cairns and Zibrowius 1997); Indonesia (van der Horst 1922; Cairns and Zibrowius 1997); New Caledonia ( Kitahara and Cairns 2021); Galápagos Islands ( Cairns 1991); Cocos Island (Durham 1962); Mozambique? ( MacNae and Kalk 1958); 2-700 m.

Remarks.

Based on a literature comparison, the South African Rhizopsammia verrilli differs from the previously reported Indo-Pacific representatives by having four complete cycles instead of five, the last incomplete. Striking similarities between R. verrilli and R. wettsteini Scheel & Pillai, 1983 have been highlighted ( Arrigoni et al 2014), however specimens of the latter have not been examined and thus a comparison is not detailed herein. Specimens reported here are new records for the South African region, but not for the southwest Indian Ocean, as this R. verrilli has been recorded off Mozambique by MacNae and Kalk (1958). This Mozambican record forms part of the Inhaca collection, presumably examined by Boshoff and reported in MacNae and Kalk’s (1958). Unfortunately, the subsequent Boshoff (1981) checklist historically raised concerns on the reliability of R. verrilli in the southwest Indian Ocean. Furthermore, Cairns and Keller (1993) did not list this species in their southwest Indian Ocean account. However, the specimens reported herein confirm the occurrence R. verrilli in the region. Nonetheless, the Inhaca collection is of concern and the examination of these specimens is of high priority for biodiversity assessments of the region.

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.