Labyrinthocyathus delicatus (von Marenzeller, 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

Labyrinthocyathus delicatus (von Marenzeller, 1904)

Fig. 4G, H

Ceratotrochus delicatus von Marenzeller, 1904a: 302, pl. 18, fig. 18.

Cyathoceras cornu . - Gardiner 1904: 121-122.

Labyrinthocyathus sp. - Cairns 1979: 70, pl. 11, figs 10-11.

Paracyathus indicus . - Boshoff 1981: 38.

Labyrinthocyathus delicatus . -Zibrowuis and Gili 1990: 44. - Cairns and Keller 1993: 244.

Type locality.

Off the Agulhas Bank, South Africa (SS ' Valdivia ' stn. 104: 35°16'00"S, 22°26'00"E); 155 m (von Marenzeller 1904a).

Type material.

Unknown.

Material examined.

DEFF_AI2-INV 135 (2 specimens): Eastern margin, 37 km from Cintsa/ 21 km off Cwili Estuary, 32°49'59.99"S, 28°30'00.00"E; 228 m. SAMC_A073158 (2 specimens): Eastern margin, 10 km from Port Edward / 24 km off Bilanhlolo Estuary, 31°05'48.00"S, 30°18'47.99"E ; 140 m. SAMC_A073173 (1 specimen): Eastern margin, 24 km from Coffee Bay / 17 km off Mdumbi Estuary, 31°58'00.00"S, 29°22'59.99"E ; 200 m. SAMC_A073180 (13 specimens): Southern margin, 33 km from Mazeppa Bay / 24 km off Cwili Estuary, 32°45'47.88"S, 28°36'24.12"E ; 240- 250 m. SAM_H1482 (4 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_H2805 (1 specimen): Eastern margin, locality data unknown; 550 m. SAM_H2828 (1 specimen): 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_H2832 (1 specimen): Southern margin, 3 km from Kei Mouth /off De Mond-Heuningnes Estuary, 32°42'31.81"S, 28°21'54.38"E ; 159 m. SAM_H2834 (3 specimens): Southern margin, 25 km from Gonubie / 24 km off Gqunube Estuary, 33°06'17.99"S, 28°10'59.99"E ; 155 m. SAM_H2835 (20 specimens): Southern margin, 29 km from Cintsa / 3 km off Morgan Estuary, 32°42'30.47"S, 28°22'07.88"E ; 159 m. SAM_H2836 (7 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_H2837 (2 specimens): Southern margin, 11 km from East London / 3 km off Buffalo Estuary, 33°00'53.67"S, 27°55'50.67"E ; 128 m. SAM_H2845 (2 specimens): Eastern margin, 17 km from Margate /off Boboyi Estuary, 30°53'24.00"S, 30°31'41.99"E ; 850 m. SAM_H3131 (2 specimens): Southern margin, 40 km from Cintsa / 29 km off Cwili Estuary, 32°55'00.00"S, 28°31'00.00"E ; 630 m. SAM_H3132 (1 specimen): 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_H3133 (7 specimens): Southern margin, 32 km off Mazeppa Bay / 24 km off Kobole Estuary, 32°28'36.00"S, 28°58'48.00"E ; 710- 775 m. SAM_H3134 (1 specimen): Southern margin, 28 km from Mazeppa Bay / 27 km off Kobole Estuary, 32°32'59.99"S, 28°55'00.00"E ; 775- 790 m. SAM_H4242 (1 specimen): Eastern margin, 11 km from Port St. Johns / 15 km off Bulolo Estuary, 31°39'42.00"S, 29°38'59.99"E ; 300- 540 m. ORI_DIIIg1 (1 specimen): Eastern margin, other locality unknown.

Imagery data.

AB_357 E (1 specimen): Eastern margin, 34 km from Port Dunford/38 km off Mlalazi Estuary, 29°10'00.00"S, 32°04'59.99"E; 168 m. BMNH 1973.2.20.26 (2 specimens): Eastern margin, 22 km from Port Shepstone/21 km off Damba Estuary, 30°46'59.99"S, 30°40'00.00"E; 457 m.

Description.

Corallum solitary, ceratoid to trochoid, attached to substrate through a pedicel (PD:GCD = 0.3-0.5) that expands into an encrusting base. Calice circular to slightly elliptical (GCD:LCD = 1.0-1.1), calicular margin thick and slightly serrated. Largest specimen examined (SAM_H2836) 11.6 × 11.4 mm in CD, 4.8 mm in PD, and 17.8 mm in H. Theca bears thin transverse ridges composed of fine granules. Costae poorly developed, granular, separated by faint and narrow intercostal striae, and more prominent near calicular margin. Corallum white.

Septa hexamerally arranged in four cycles according to the formula: S1-2 > S3 > S4 (48 septa). S1-2 largest septa and equal to only slightly more exsert than S2, almost reaching columella. S34/5 the size of S1-2. Higher cycle septa (S3-4) progressively less exsert. S4 ½ to ¾ the width of S3, with the least sinuous axial margin. All septal faces bear low rounded granules. Fossa moderately deep, containing a well-defined labyrinthiform columella composed of interconnected lamellar plates.

Distribution.

Regional: Southern to eastern margin, off East London extending towards Port Dunford; 128-790 m. Elsewhere: off south-eastern Mozambique ( Cairns and Keller 1993); 155-1000 m.

Remarks.

Labyrinthocyathus delicatus was described by von Marenzeller (1904a) based on specimens sampled from off the Agulhas Bank, South Africa. Subsequently, Gardiner (1904) also reported on specimens collected off the Agulhas region but as Cyathoceras cornu . Zibrowius and Gili (1991) noted that Gardiner’s (1904) specimens of C. cornu were representatives of L. delicatus . As Gardiner’s (1904) specimens were not examined during the course of the present study, their identification remains tentative but in agreement with Zibrowius and Gili (1990) and Cairns and Keller (1993) as L. delicatus . Boshoff (1981) further reported the species in the region, but as Paracyathus indicus Duncan, 1889.

Figures

Figure 4. A, B Heterocyathus alternatus (ORI _ DIIIe 1 _ 1, locality data unknown) A calicular view B lateral view C, D Heterocyathus monileseptatum sp. nov. (SAM _ H 1431, off Durban Harbour, 99 m) C calicular view D lateral view E, F Heterocyathus sulcatus (SAMC _ A 073123, off Shaka's Rock, 100 - 105 m) E calicular view F lateral view G, H Labyrinthocyathus delicatus (SAM _ H 2836, off East London, 146 - 238 m) G calicular view H lateral view I, K Monohedotrochus capensis comb. nov. I, J (SAMC _ A 088924, off Kidds Beach, 247 - 147 m) I calicular view J lateral view K (SAM _ H 3210, off Scottburgh, 690 m) calicular view L, M Polycyathus sp. (USNM 91677, off Port Dunford, 69 m) L calicular view M full view N, O Rhizosmilia robusta (USNM 91689, off Kosi Bay Estuary, 74 m) N calicular view O lateral view P Solenosmilia variabilis (SAM _ H 3158, off Cintsa, 630 m) P full view. Scale bars: 10 mm (A-G, I-O); 100 mm (H, P).