Atlantia denticulata Filander & Kitahara, 2021

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

Atlantia denticulata Filander & Kitahara sp. nov.

Fig. 7G, H

Type locality.

Off Gouritsmond, Southern margin of South Africa (FV 'Compass Challenger’, 35°31'52.31"S, 22°07'25.28"E); 170 m.

Material.

Holotype: SAMC_A090157, Southern margin, 132 km from Gouritsmond/ 143 km off Goukou Estuary, 35°31'52.31"S, 22°07'25.28"E; 170 m. Paratypes: DEFF/SAEON_CCH009 (15 specimens): Southern margin, 132 km from Gouritsmond/ 133 km off Gourits Estuary, 35°31'52.31"S, 22°07'25.28"E; 170 m. DEFF/SAEON_ A32786 (3 specimens): Southern margin, 145 km from Gouritsmond/ 152 km off Goukou Estuary, 35°39'19.79"S, 22°02'10.68"E ; 175 m. UCTES_SST91P (4 specimens): Southern margin, other locality data unknown.

Etymology.

The species name Atlantia denticulata (derived from the Latin dens for small tooth + suffix - ātus) refers to the axial margins of S3 being dentate.

Description.

Corallum phaceloid to dendroid. Budding extra-tentacular from base or theca of parent corallite. Holotype consists of 84 corallites, and is 84.6 mm in H. Calice circular to elliptical (GCD:LCD = 1.0-1.1). Epitheca absent. Theca porous, especially near calicular margin. Costae thick, equal in width, granular, and extend to base. Intercostal striae deep. Corallum white.

Septa hexamerally arranged in a normal fashion, with four complete cycles according to the formula: S1 > S2 > S3 > S4 (48 septa). S1 almost meet opposite septa with vertical axial margins. S21/3 to ½ width of S1, also with vertical axial margins. S31/3 the width of S2 and have slightly laciniate to dentate axial margins. S4 rudimentary, bearing dentate to laciniate axial margins. Septa not exsert. Septal faces bear granules sparsely arranged. Fossa deep, containing a rudimentary columella.

Distribution.

Regional: Southern margin, off Gouritsmond; 170 m. Elsewhere: Only known from the type locality.

Remarks.

The genus Atlantia was recently described by Capel et al. (2020), who outlined the significance of the normally arranged septa (i.e., Pourtalès Plan absent), poorly developed columella, and uniform corallum porosity in distinguishing the genus from other dendrophylliids. The colonies examined herein represents a new species in the genus. Atlantia denticulata sp. nov. differs from the type species (A. Atlantia caboverdiana ) in its primary septa extending further into columella (almost meeting with other primaries), tertiary septa never fusing to neighbouring primaries, the rudimentary nature of the columella, and the axial margins of S3 consistently being dentate to laciniate.

Figures

Figure 7. A, D Vaughanella concinna A, B (MN _ SM 134, off Port Edward, 900 m) A calicular view B lateral view C, D (SAMC _ A 072973, locality data unknown, 517 m) C calicular view D lateral view E, F Deltocyathus rotulus (USNM 91550, off Scottburgh, 1360 m) E calicular view F lateral view G, H Atlantia denticulata sp. nov. (SAMC _ A 090157, off Gouritsmond, 170 m) G close-up of corallites H full view I, J Balanophyllia (Balanophyllia) bonaespei (USNM 1423303, off the Agulhas, 32 m) I calicular view J lateral view K, N Balanophyllia (Balanophyllia) capensis K, M (SAM _ H 3048, off Cape Point, depth unknown) calicular view L, N (BMNH _ 1939.7.20.479 - 500, locality data unknown) lateral view O, P Balanophyllia (Balanophyllia) diademata (SAMC _ A 073016, off Richards Bay, 500 m) O calicular view P Lateral view. Scale bars: 10 mm (A-H, K-P); 100 mm (I, J).