Trochocyathus (Trochocyathus) sp. 2

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

Trochocyathus (Trochocyathus) sp. 2

Fig. 6C-F

Material examined.

DEFF/SAEON_ A33997 (1 specimen): Southern margin, 39 km from Cape Padrone / 40 km off Boknes Estuary, 34°03'53.52"S, 26°42'11.58"E; 100 m. DSCS-INV 529 (1 specimen): Southern margin, 35 km from Cape St. Francis / 70 km off Slang Estuary , 34°47'05.0"S, 24°45'42.3"E; 392-418 m SAMC_A073141 (3 specimens): Eastern margin, 33 km from Coffee Bay / 18 m off Ntlonyane Estuary, 32°16'41.88"S, 29°06'00.00"E; 300 m. SAMC_A073150 (3 specimens): Southern margin, 26 km from Mazeppa Bay / 33 km off Great Kei Estuary, 32°41'12.12"S, 28°43'54.12"E; 480- 490 m. SAMC_A073166 (1 specimen): Eastern margin, 19 km off Port St. Johns / 21 km off Bulolo Estuary, 31°45'00.00"S, 29°40'47.99"E; 125 m. SAMC_A073175 (1 specimen): Eastern margin, 28 km from Coffee Bay / 16 km off Hluleka Estuary, 31°55'58.79"S, 29°25'12.00"E; 300 m. SAMC_A073211 (3 specimens): Eastern margin, 5 km from Cape Vidal / 16 km off St Lucia Estuary, 28°08'24.00"S, 32°36'24.00"E; 165 m. SAMC_A073235 (2 specimens): Southern margin, False Bay ; depth unknown. SAMC_A088920 (1 specimen): Southern margin, 38 km from Cintsa / 22 km off Cwili Estuary, 32°50'30.72"S, 28°30'41.33"E; 250- 226 m. SAMC_A088921 (3 specimens): Southern margin, 140 km from Agulhas / 144 km off Ratels Estuary, 36°02'29.58"S, 19°41'24.61"E; 445- 463 m. SAMC_A088925 (1 specimen): Southern margin, 140 km from Agulhas / 144 km off Ratels Estuary, 36°02'29.58"S, 19°41'24.61"E; 445- 463 m. SAMC_A088926 (8 specimens): Southern margin, 140 km from Agulhas / 144 km off Ratels Estuary, 36°02'29.58"S, 19°41'24.61"E; 445- 463 m. SAMC_A090146 (5 specimens): Southern margin, 68 km from Cape St. Francis / 70 km off Slang Estuary, 34°47'35.77"S, 24°38'35.69"E; 520 m. SAMC_A090147 (2 specimens): Southern margin, 140 km from Agulhas / 144 km off Ratels Estuary, 36°02'29.58"S, 19°41'24.61"E; 445- 463 m. SAM_H1243 (3 specimens): Southern margin, 11 km from Infanta / 12 km off Duiwenhoks Estuary, 34°27'00.00"S, 20°58'00.00"E; 47 m. SAM_H1370 (1 specimen): Southern margin, 28 km from Gonubie / 27 km off Buffalo Estuary, 33°09'29.99"S, 28°03'06.00"E; 86 m. SAM_H1384 (1 specimen): Southern margin, 2 km from Mosselbaai / 11 km off Hartenbos Estuary, 34°11'10.12"S, 22°09'40.59"E; 95 m. SAM_H1388 (14 specimens): Southern margin, 11 km from East London / 5 km off Gouda Estuary, 33°05'03.24"S, 27°49'33.40"E; 146- 238 m. SAM_H1391 (1 specimen): Southern margin, 24 km from Cape Padrone / 35 km off Boknes Estuary, 33°58'00.00"S, 26°21'00.00"E; 46 m. SAM_H1400 (1 specimen): Southern margin, 74 km off Cape St. Francis / 83 km off Slang Estuary, 34°52'00.00"S, 24°56'59.99"E; 137 m. SAM_H1407 (1 specimen): Southern margin, 2 km from Mosselbaai / 11 km off Hartenbos Estuary, 34°11'10.12"S, 22°09'40.59"E; 192 m. SAM_H1408 (1 specimen): Southern margin, 14 km from Mazeppa Bay / 20 km off Great Kei Estuary, 32°34'00.00"S, 28°33'00.00"E; 174 m. SAM_H1419 (1 specimen): Southern margin, 4 km from Plettenberg Bay / 7 km off Piesang Estuary, 34°06'00.00"S, 23°23'59.99"E; 146 m. SAM_H1443 (26 specimens): Southern margin, 241 km from Agulhas / 247 km off De Mond-Heuningnes Estuary, 36°40'00.00"S, 21°25'59.99"E; 200 m. SAM_H1487 (13 specimens): Southern margin, 2 km from Mosselbaai / 11 km off Hartenbos Estuary, 34°11'10.12"S, 22°09'40.59"E; 229 m. SAM_H3103 (2 specimens): Southern margin, 2 km from Mosselbaai / 11 km off Hartenbos Estuary, 34°11'10.12"S, 22°09'40.59"E; 165- 183 m. SAM_H3106 (9 specimens): Southern margin, 846 km from Port St. Johns / 842 km off Mkweni Estuary, 36°40'00.00"S, 21°25'59.99"E; 366 m. SAM_H3111 (1 specimen): Eastern margin, 18 km from Cape Vidal / 27 km off Mfolozi Estuary, 28°16'18.00"S, 32°38'48.00"E; 670 m. SAM_H3114 (2 specimens): Southern margin, 11 km from East London / 5 km off Gouda Estuary, 33°05'03.24"S, 27°49'33.40"E; 146- 238 m. SAM_H3116 (9 specimens): Eastern margin, 22 km from Cape Vidal / 28 km off Mfolozi Estuary, 28°17'23.99"S, 32°40'47.99"E; 550 m. SAM_H3170 (15 specimens): Eastern margin, 28 km from Coffee Bay / 19 km off Bulungulu Estuary, 32°14'53.99"S, 29°10'23.99"E; 620- 560 m. SAM_H3172 (3 specimens): Southern margin, 29 km from Mazeppa Bay / 25 km off Kobole Estuary, 32°29'30.00"S, 28°57'06.00"E; 650- 700 m. SAM_H3173 (1 specimen): Southern margin, 47 km from Port Alfred / 14 km off Mgwalana Estuary, 33°30'18.00"S, 27°22'05.99"E; 80 m. SAM_H3175 (1 specimen): Eastern margin, 30 km from Coffee Bay / 20 km off Bulungulu Estuary, 32°15'00.00"S, 29°09'06.00"E; 520- 500 m. SAM_H3176 (3 specimens): Eastern margin, 30 km from Scottburgh / 20 km off Fafa Estuary, 30°33'24.00"S, 30°48'35.99"E; 690 m. SAM_H3830 (2 specimens): Western margin, 49 km from Cape Point / 51 km off Buffels Wes Estuary, 34°43'18.00"S, 18°12'29.99"E; 360- 365 m. SAM_H3832 (3 specimens): Southern margin, 14 km from Cape Point / 10 km off Buffels Wes Estuary, 34°13'59.99"S, 18°30'00.00"E; 42 m.

Description.

Corallum ceratoid to trochoid, and attached to a variably sized pedicel (PD:GCD = 0.2-0.7). Calice circular to slightly elliptical (GCD:LCD = 1.0-1.2), with serrate calicular margin. Largest specimen examined (SAM_H1400) 17.4 × 17.2 mm in CD, 6.0 mm in PD, and 39.6 mm in H. Costae prominent from calicular margin to base, ca. the same width as associated septa, equidistant, low, bearing small granules, and separated by thin intercostal furrows. Corallum white.

Septa hexamerally arranged in five cycles, the last cycle being incomplete, according to formula S1> S2 ≥ S3> S4> S5> S6 (≤ 60 septa). S1 most exsert, independent, slightly wider than S2, and bearing straight to slightly sinuous axial margin. S2 slightly less exsert than S1, and extending slightly less to centre of calice with moderately sinuous axial margin. S3 equal or slightly smaller than S2, but have axial margin equally sinuous. S4 predominantly restricted to upper calice in specimens with four septal cycles, but dimorphic and variable in development half-systems bearing S5 or S5-6 (e.g., SAMC_A090146 = 6:6:12:24:10:2, SAM_H1407 = 6:6:12:24:12). In the latter, S4 closer to S1 have the same rudimentary profile as S5 and S4 flanked by S5 having a similar profile as S3 or slightly less wide. S4 axial margin coarsely dentated. If present, S6 restricted to calicular margin. S3-5 progressively less exsert than S1-2. Pali present before all but last septal cycle. P2 most recessed. P2-3 form a chevron-like pattern before S2, a pattern also taken by S4 flanked by S5 which sometimes bear pali. All septal and palar faces granulated. Fossa moderately deep, containing a papillose columella composed of a group of 17-30 rod elements which mostly are as high as pali elements.

Distribution.

Regional: Western to eastern margin of South Africa, off Cape Point extending towards Cape Vidal; 42-700 m.

Remarks.

Although specimens examined closely resemble Trochocyathus (T.) sp. 1 cf. T. rawsonii Guynia sensu Gardiner (1904) in having well-developed costae extending from the calicular margin to base, an often curved coralla, and the presence of S5, Trochocyathus sp. 2 occasionally has a pair of S6, even though the fifth cycle is incomplete (SAMC_A090146 = 6:6:12:24:10:2), and an independent S1 which extends further to the columella. Apart from that, the specimens reported herein differ from Trochocyathus (T.) sp. 1 cf. T. rawsonii Guynia sensu Gardiner (1904) in having a systematic development of septal cycles (irrespective of an increase mm in CD). While this material may represent a new species of Trochocyathus , a name will not be introduced until the intraspecific variation is better understood and compared with that from congeners.

Figures

Figure 6. A, B Trochocyathus (Trochocyathus) sp. 1 (SAM _ H 1449, off Mazeppa Bay, 174 m) A calicular view B lateral view C, F Trochocyathus (Trochocyathus) sp. 2 C, D (SAM _ H 1388, East London, 90 m) C calicular view C lateral view E, F (SAM _ H 1407, off Mosselbaai, 192 m) E calicular view F lateral view G, L Trochocyathus (Trochocyathus Trochocyathus) sp. cf. Trochocyathus Trochocyathus rawsonii Guynia sensu Cairns & Keller, 1993 G, J (SAM _ H 1440, off East London, 90 m) G calicular view H lateral view I calicular view J lateral view. 1993 K, L (SAMC _ A 090156, off Sedgefield, 74 m) K calicular view L lateral view M, P Trochocyathus (Trochocyathus) sp. 3 M, N (SAM _ H 3124, off East London, 90 m) O calicular view P lateral view O, P (BMNH 1939.7.20.47, off Richards Bay, 165 m) O calicular view P lateral view. Lateral view. Scale bars: 10 mm.