Tropidocyathus lessonii (Michelin, 1842)

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

Tropidocyathus lessonii (Michelin, 1842)

Fig. 15O-P

Flabellum lessonii Michelin, 1842: 119.

Tropidocyathus lessoni . - Milne-Edwards and Haime 1857: 57. -Gardiner and Waugh 1938: 194.- Cairns 1989a: 33-34, pl. 16D-L. -Cairns 1994: 67, pl. 29A, B. - Cairns and Keller 1993: 253, fig. 7C.

Trochocyathus (Tropidocyathus) lessoni . - Alcock 1902a: 17, pl. 2, figs 14, 14A.

Trochocyathus (Tropidocyathus) cf. lessoni . - Yabe and Eguchi 1942b: 124.

Trochocyathus (Tropidocyathus) wellsi Yabe & Eguchi, 1942b: 153, pl. 10, fig. 22A, B.

Tropidocyathus lessonii. - Cairns and Zibrowius 1997: 146-147. - Cairns 1997: 15-16, figs 1E, 4E, 7D. - Cairns 1998: 390-392. - Cairns 1999a: 110, fig. 17C. - Kitahara and Cairns 2021: 147-148, figs 68A-C, I-L, 7.

Type locality.

Unknown.

Type material.

The holotype is deposited at the MNHNP ( Cairns 1989a).

Material examined.

SAMC_A073064 (1 specimen): Eastern margin, 5 km from Cape Vidal / 16 km off St Lucia Estuary, 28°07'30.00"S, 32°36'24.11"E; 75- 80 m. SAMC_A073095 (3 specimens): Eastern margin, 66 km south of Ponta Do Ouro / 15 km off Mgobezeleni Estuary, 27°25'59.87"S, 32°44'30.12"E; 55- 100 m. SAMC_A073106 (1 specimen): Eastern margin, 66 km from Cape Vidal / 7 km off Mgobezeleni Estuary, 27°33'11.88"S, 32°43'00.12"E; 140 m. SAMC_A073131 (4 specimens): Eastern margin, 39 km from Cape Vidal / 29 km off Mgobezeleni Estuary, 27°47'23.99"S, 32°38'53.87"E; 65- 70 m. SAMC_A073135 (1 specimen): Eastern margin, 19 km from Coffee Bay / 18 km off Mdumbi Estuary, 32°02'53.87"S, 29°19'41.87"E; 250- 280 m. SAMC_A073149 (1 specimen): Eastern margin, 19 km south of Ponta Do Ouro / 12 km off Kosi-Kumpungwini (Sifungwe) Estuary, 27°01'05.87"S, 32°55'12.00"E; 78 m. SAMC_A073191 (1 specimen): Eastern margin, 41 km south of Ponta Do Ouro / 26 km off Kosi Bay Estuary, 27°12'53.99"S, 32°49'41.87"E; 66- 71m. SAMC_A073209 (1 specimen): Eastern margin, 37 km south of Ponta Do Ouro / 23 km off Kosi Bay Estuary, 27°11'05.99"N, 32°50'53.88"E; 100 m. SAMC_A073214 (1 specimen): Eastern margin, 37 km from Cape Vidal / 32 km off Mgobezeleni Estuary, 27°48'47.88"S, 32°38'53.87"E; 50 m. SAMC_A073218 (1 specimen): Eastern margin, 42 km south of Ponta Do Ouro / 27 km off Kosi Bay Estuary, 27°13'30.00"S, 32°49'30.00"E; 74 m. SAMC_A090079 (1 specimen): Eastern margin, 56 km south of Ponta Do Ouro / 25 km off Mgobezeleni Estuary, 27°20'35.87"S, 32°46'41.88"E; 60 m. SAM_H3101 (2 specimens): Eastern margin, 19 km from Shaka’s Rock / 3 km off Mdloti Estuary, 29°38'59.99"S, 31°07'59.99"E; 71- 73 m. SAM_H3102 (1 specimen): Eastern margin, 6 km from Durban / 9 km off Umgeni Estuary, 29°52'59.99"S, 31°03'04.99"E; 86 m. SAM_H4583 (1 specimen): Eastern margin, 41 km south of Ponta Do Ouro / 26 km off Kosi Bay Estuary, 27°13'05.99"S, 32°49'30.00"E; 60 m. SAM_H4588 (2 specimens): Eastern margin, 42 km south of Ponta Do Ouro / 27 km off Kosi Bay Estuary, 27°13'35.99"S, 32°49'17.99"E; 75 m.

Description.

Corallum cuneiform, with thecal edge crests extending laterally. Base rounded. Calice elliptical (GCD:LCD = 1.4-1.6), calicular margin slightly serrated. Largest specimen examined (SAMC_A073064) 16.8 × 10.8 mm in CD, and 16.4 mm in H. Costae broad, flat, variable in size. C1-3 wider than C4, and bearing 3-4 granules across width. C4 bear two granules across a costal width granules. Intercostal striae narrow, shallow, and fainting towards base and thecal crests. Thecal crests also lack costae, which are replaced by uniform granules. Corallum predominantly orange with white calicular margin and septa.

Septa hexamerally arranged in four cycles according to the formula: S1> S2> S4> S3 (48 septa). S1 highly exsert, and extends to columella deep in fossa with straight axial edges. P1 small and separated from its septum by a small notch. S2 equally exsert, slightly less wide than S1, bearing a broad and larger palus. S3 less exsert than S1-2, ¾ the width of S1-2, and have a slightly sinuous axial margin. Each S3 bears a large palus, which joins P2 producing a V-shape appearance. S4 less exsert than S3, but slightly wider. S4 axial edges straight. All palar and septal faces bear sharp spines. Columella papillose, elongated, aligned to principal S1, sometimes fused as a lamella in larger specimens. Fossa moderately deep.

Distribution.

Regional: Eastern margin of South Africa, off Coffee Bay and extending towards Kosi-Kumpungwini (Sifungwe) Estuary (19 km south of Ponta Do Ouro: Mozambique); 50-280 m. Elsewhere: Tanzania (Gardiner and Waugh 1938); Mozambique; Kenya; north-eastern Somalia ( Cairns 1989b); Vanuatu; and Wallis and Futuna Islands ( Cairns 1999a); Philippines; Indonesia; China ( Yabe and Eguchi 1942b; Cairns and Zibrowius 1997); New Caledonia ( Kitahara and Cairns 2021); Australia ( Cairns 1998); 50-421 m.

Remarks.

Tropidocyathus lessonii is distinctive from other South African Turbinoliidae in its thecal crests and colouration. However, it may be mistaken with Endopachys grayi , which belongs to another family distinguished by its porous corallum ( Dendrophylliidae ). Tropidocyathus lessonii differs from its only extant congener, T. labidus Cairns & Zibrowius, 1997, in its conspicuous thecal edge crests.

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).