Heterocyathus aequicostatus Milne-Edwards & Haime, 1848

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

Heterocyathus aequicostatus Milne-Edwards & Haime, 1848

Fig. 3O, P

Heterocyathus aequicostatus Milne-Edwards & Haime, 1848a: 324, pl. 10, fig. 8. - Milne-Edwards and Haime 1857: 51. - Alcock 1893: 141. - Gardiner 1904: 105-112, 125 (in part), pl. 3, figs 1-11, 22-32, 39-43. - Gardiner 1905: 955. -Bourne 1905: 193-194, 213-226, pl. 3, pl. 4, figs 12-21. -Harrison and Poole 1909a: 898-899, pl. 85, fig. lA-F. - Harrison and Poole 1909b: 913. - Harrison 1911: 1026, pl. 58, fig. 12. -Faustino 1927: 83-87, pl. 8, figs 1-7. - Yabe and Eguchi 1932b: 443. -Gardiner and Waugh 1938: 186-187. -Umbgrove 1938: 265. - Eguchi 1941: 417. -Yabe and Eguchi 1941 b: 213, fig. 6A, B. -Yabe and Eguchi 1941 c: 270, figs 3-4. -Crossland 1952: 102-103. -Durham and Barnard 1952: 87-88, pl. 11, fig. 49A-D. -Scheer and Pillai 1983: 158, pl. 36, fig. 9. - Wells 1984: 310, fig. 4.1. - Zibrowius and Grygier 1985: 121. -Pillai 1986: 188. - Veron 1986: 558-559 (in part). -Hu 1988: 146, 147, pl. 3, figs 9, 12, 13, 16, 17. -Hoeksema and Best 1991: 226-230, figs 1-11. -Hodgson and Carpenter 1995: 243. - Cairns 1998: 382-384, fig. 3A, B. - Cairns et al. 1999: 22. -Veron 2000: 412-413, figs 1-4. -Stolarski et al. 2001: 324, figs 6A-D. -Cairns 2004a: 281. - Cairns 2009: 12. - Kitahara and Cairns 2021: 528-529, 531, figs 290, 291A-G.

Heterocyathus roussaeanus Milne-Edwards & Haime, 1848a: 324-325, pl. 10 fig. 9, 9A. -Vaughan and Wells 1943: pl. 41 figs 16, 16A.

Heterocyathus cochlea . - Gray 1849: 77, pl. 2, figs l, 2A. -Gray 1850: 410.

Psammoseris hemispherica . - Milne-Edwards and Haime 1851: 127. - Veron 1986: 610.

Stephanoseris rousseaui . - Milne-Edwards and Haime 1851: 127.

Stephanoseris lamellosa Verrill, 1865: 149.

Heterocyathus philippinensis Semper, 1872: 254 (in part: pl. 20 figs 13, 14). - Eguchi 1941 a: 414.

Heterocyathus japonicus . - Yabe and Eguchi 1942b: 127-128, pl. 11 fig. 6 A, B.

Type locality.

Unknown.

Type material.

The type material was never traceable (Cairns 2004a).

Material examined.

SAMC_A073100 (5 specimens): Eastern margin, 414 km south of Ponta Do Ouro / 41 km off Groot Berg Estuary, 27°13'30.00"S, 32°49'30.00"E; 78 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_A073186 (1 specimen): Eastern margin, 20 km from Durban / 13 km off Mbokodweni Estuary, 30°01'05.87"S, 31°03'11.88"E; 150 m. USNM 90840 (1 specimen): 26 km from Port St. Johns /off Bulolo Estuary, 29°34'47.99"S, 31°41'59.99"E; 138 m.

Description.

Corallum free, squat and always encapsulating a gastropod shell colonised by a sipunculid worm. Sipunculid efferent pore <2 mm in diameter, located aborally. Base flat, but area with pore more prominent, giving a pear-shaped appearance. Calice slightly elliptical (GCD:LCD = 1.1). Largest specimen examined (SAMC_A073186) 8.2 × 7.8 mm in CD, and 4.6 mm in H. Costae equidistant, separated by narrow intercostal striae. Calicular margin lanceted. Corallum creamy.

Septa crowded and hexamerally arranged in four cycles according to the formula: S1> S2> S4> S3 (48 septa). S1 most exsert, with rounded upper and oblique axial margins. S1 extend towards columella and bear a paliform lobe. S2 less exsert, ¾ the width of S1, and bearing multiple paliform lobes, which extend towards columella. S3 least exsert and smallest septa, but bear ≤ five paliform lobes. S4 almost as exsert as S2, bearing a paliform lobe (P4) that fuses to adjacent P3. All paliform lobes (P1-4) inclined towards columella. All septa have straight axial margins. Septal and palar faces granulated. Fossa shallow, containing a papillose columella composed of 10-25 cylindrical elements which are indistinguishable from pali.

Distribution.

Regional: Eastern margin of South Africa, 19 km from Durban extending towards Groot Berg Estuary (414 km south of Ponta Do Ouro: Mozambique); 78-145 m. Elsewhere: Zanzibar (Gardiner and Waugh 1938); Australia ( Cairns 1998); Japan ( Verrill 1866); China; Thailand ( Gray 1849); Philippines; and Indonesia (Hoeksema and Best 1991); New Caledonia ( Kitahara and Cairns 2021); 0-268 m.

Remarks.

Heterocyathus aequicostatus resembles H. alternatus in septal formula (S1> S2> S3> S4), septa having straight axial margins, and in S3 bearing ≤ five pali, but can be distinguished in S1 bearing only one palus as compared with bearing two to three paliform lobes as in H. alternatus . Differences in costae among the two species may also be a distinguishing feature: H. aequicostatus has same sized costae as compared with those of H. alternatus Guynia sensu Hoeksema and Best 1991 that vary in size (with C1-2 sometimes being slightly narrower than other costae). Heterocyathus aequicostatus was first reported off South Africa by Gardiner (1904), who detailed the intraspecific variation by comparing the eastern margin to the western margin representatives. The examined eastern margin South African representatives add no new taxonomic knowledge to what is already known apart from extending the depth range reported by Hoeksema and Best (1991). Additionally, specimens examined include zooxanthellate representatives (> 40 m) (Hoeksema and Best 2015) and should therefore not be considered in biodiversity assessments focusing on azooxanthellate forms.

Figures

Figure 3. A, B Caryophyllia (Caryophyllia) stellula (SAM _ H 1485, off Agulhas, 200 m) A calicular view B lateral view C, D Caryophyllia (Caryophyllia) valdiviae (SAM _ H 3108, off Durban, depth unknown) C calicular view D lateral view E, F Crispatotrochus cornu (UCT _ NAD 17 F, off Isipingo, 49 m) E calicular view F lateral view G, J Desmophyllum dianthus G, H (SAMC _ A 077974, off Paternoster, 440 m) G calicular view H lateral view I, J (BMNH. 1939.7.20.218, locality data unknown) I calicular view J lateral view K, L Desmophyllum pertusum (SAM _ H 1605, off Melkbosstrand, depth unknown) K calicular view L lateral view M, N Goniocorella dumosa (SAM _ H 3190, off Kidds Beach, 760 m) M calicular view N lateral view O, P Heterocyathus aequicostatus (SAMC _ A 073186, off Durban, 150 m) O calicular view P lateral view Scale bars: 10 mm (A-I, K-P); 100 mm (J).