Sphenotrochus (Eusthenotrochus) gilchristi Gardiner, 1904

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

Sphenotrochus (Eusthenotrochus) gilchristi Gardiner, 1904

Fig. 15G, H

Sphenotrochus gilchristi Gardiner, 1904: 98-99, pl. 1, figs A-G. - Boshoff 1981: 39. - Zibrowius and Gili 1990: 44.

Eusthenotrochus moseri Wells, 1935: 530.

Sphenotrochus (Eusthenotrochus) moseri . -Wells 1935: 530-532, pl. 18, figs 5, 6.

Sphenotrochus dentosus Boshoff 1981: 39.

Sphenotrochus sp. (incertae sedis). - Boshoff 1981: 39.

Sphenotrochus (Eusthenotrochus) gilchristi . - Cairns and Keller 1993: 259, fig. 7A, B.

Type locality.

Near Kowie, South Africa (33°45'20.0"S 26°44'20.0"E); 79-81m ( Gardiner 1904).

Type material.

Two syntypes are deposited at the BMNH.

Material examined.

ORI_DIIIi2 (2 specimens), ORI _ DIIIi3 (3 specimens), SAMC_A073226 (1 specimen), SAMC_A073075 (1 specimen): Locality data unknown. SAMC_A073232 (1 specimen): Southern margin, 21 km from Cape Point / 14 km off Sand Estuary, 34°10'59.99"S, 18°34'59.99"E; 42 m. SAMC_A073236 (4 specimens): Southern margin, 22 km from Cape Point / 4 km off Elsies Estuary, 34°09'59.99"S, 18°27'29.99"E; 24 m. SAMC_A090086 (14 specimens): Southern margin, 22 km from Cape Point / 4 km off Elsies Estuary, 34°09'59.99"S, 18°27'29.99"E; 24 m. SAMC_A090087 (3 specimens): Southern margin, 18 km from Cape Point / 16 km off Buffels Wes Estuary, 34°13'00.00"S, 18°34'59.99"E; 44 m. SAMC_A090088 (6 specimens): Southern margin, 80 km from Gouritsmond / 91 km off Blinde Estuary, 34°59'00.00"S, 22°18'00.00"E; 106 m. SAM_H1376 (1 specimen): Southern margin, 28 km from Port Alfred / 3 km off Old Womans’ Estuary, 33°30'00.00"S, 27°08'59.99"E; 183 m. SAM_H1405 (1 specimen): Western margin, 51 km from Cape Point / 48 km off Krom Estuary , 34°28'59.87"S, 17°58'00.11"E; depth unknown. SAM_H1413 (1 specimen): Southern margin, 11 km from Kenton On Sea / 11 km off Boesmans Estuary, 33°45'19.99"S, 26°44'19.99"E; 79- 80 m. SAM_H1480 (1 specimen): Southern margin, 35 km from Port Alfred / 5 km off Mpekweni Estuary, 33°27'59.99"S, 27°12'59.99"E; 97 m. SAM_H3204 (2 specimens): Southern margin, 6 km from Kenton On Sea / 5 km off Boknes Estuary, 33°43'07.59"S, 26°37'37.95"E; 90 m. SAM_H3205 (7 specimens): Southern margin, 37 km from Port Elizabeth / 32 km off Bakens River Estuary, 34°05'29.99"S, 25°55'14.99"E; 123 m. SAM_H3206 (3 specimens): Southern margin, 7 km from East London / 5 km off Buffalo Estuary, 33°02'59.99"S, 27°57'00.00"E; 59 m. SAM_H3207 (2 specimens): Southern margin, 47 km from Kidds Beach / 13 km off Bira Estuary, 33°29'03.99"S, 27°22'59.99"E; 80 m. SAM_H3208 (3 specimens): Southern margin, 31 km from Gonubie /off Gqunube Estuary, 33°09'59.99"S, 28°12'00.00"E; 90 m. SAM_H4243 (1 specimen): Eastern margin, 16 km from Scottburgh / 12 km off Mkomazi Estuary, 30°15'00.00"S, 30°54'18.00"E; 100 m. SAM_H4590 (1 specimen): Southern margin, 16 km from Cape Point / 12 km off Elsies Estuary, 34°13'08.99"S, 18°31'59.99"E; 37 m.

Imagery data.

BMNH 1970.1.26.7 (2 syntypes imaged): Eastern margin, north of Durban; 79-81m; DTE (sub-genus type): Southern margin, 113 km from Gouritsmond/125 km off Blinde Estuary, 35°15'59.99"S, 22°26'06.99"E; 155 m.

Description.

Corallum cuneiform, appearing swollen around theca in lateral view. Base rounded giving a V-shaped appearance in side view. Calice elliptical (GCD:LCD = 1.4-2.8), with serrated calicular margin. Largest specimen examined (SAM_H4243) 8.6 × 3.4 mm in CD, and 10.5 mm in H. Costae smooth, well defined, each composed of two or more discontinuous ridges per septa. S3 associated costae have three or four longer continuous ridges, which separate 5.0 mm above base. Intercostal striae vary with costae size and arrangement, appearing deep and narrow. Corallum white and sometimes orange.

Septa hexamerally arranged in three cycles according to the formula: S1-2 > S3 (24 septa). S1-2 have straight axial margins. S3 dimorphic in size: sometimes 2/3 the size of S1-2 and bearing slightly sinuous axial margin or rudimentary. All septa thick and equally exsert. Septal thickening deposits connect septa to a solid lamellar columella deeper in fossa.

Distribution.

Regional: Western to eastern margin of South Africa, from off Cape Point extending towards Scottburgh; 24-155 m. Elsewhere: Only known from South Africa; 24-165 m.

Remarks.

Sphenotrochus (E.) gilchristi was first reported in the region by Gardiner (1904), and was subsequently placed in a subgenus by Wells (1935) who reported it as Sphenotrochus (E.) moseri . Thereafter, Cairns and Keller (1993) reported the species in the region and extended the known regional distribution further west.

Figures

Figure 15. A, B Cyathotrochus pileus (SAMC _ A 087424, off Durban, 270 m) A calicular view B lateral view C, D Deltocyathoides orientalis (BIVa 2, locality unknown, 80) C calicular view D basal view E, F Deltocyathoides sentus (USNM 91551, off Shaka's Rock, 300 m) G, H Sphenotrochus (Eusthenotrochus) gilchristi (SAMC _ A 090086, off Cape Point, 24 m) G calicular view H lateral view I, J Sphenotrochus (Sphenotrochus) aurantiacus (SAM _ H 1416, off the Agulhas, 366 m) I calicular view J lateral view K, L Sphenotrochus (Sphenotrochus) evexicostatus (SAMC _ A 090085, locality data unknown, 43 m) K calicular view L lateral view M, N Sphenotrochus (Sphenotrochus) imbricaticostatus (USNM 91715 _ Holotype, off Kosi-Kumpungwini (Sifungwe) Estuary, 44 m) K calicular view L lateral view O, P Tropidocyathus lessonii (SAMC _ A 073218, off Kosi Bay Estuary, 74 m) O calicular view P lateral view. Scale bars: 10 mm (A-H, J-M, O-P); 2 mm (I, N).