Deltocyathus ornatus Gardiner, 1899

Kitahara, Marcelo V. & Cairns, Stephen D., 2009, A revision of the genus Deltocyathus Milne Edwards & Haime, 1848 (Scleractinia, Caryophylliidae) from New Caledonia, with the description of a new species, Zoosystema 31 (2), pp. 233-248 : 242

Deltocyathus ornatus Gardiner, 1899 ( Fig. 1E)

Deltocyathus ornatus Gardiner, 1899: 163 , 164, pl. 20, fig. 25a, b. — Gardiner & Waugh 1938: 195. — Veron 1986: 606. — Cairns 1995: 72 (in part); 1999: 98, fig. 13h, i; 2004: 280. — Cairns et al. 1999: 22.

TYPE MATERIAL. — The holotype is deposited at the BMNH.

TYPE LOCALITY. — Baie du Santal, Lifu, Loyalty Islands, 73 m.

NEW RECORDS. — BATHUS 4, stn DW 887, 4 specimens (MNHN-Scl.2008-0010); stn DW 902 ( MNHN- Scl.2008-0012); 1 specimen ( USNM 1114163 ) ; stn DW 903, 1 specimen (MNHN-Scl.2008-0011). — NOR- FOLK 2, stn DW 2092, 4 specimens ( USNM 1114145 ) ; stn DW 2117, 5 specimens (MNHN-Scl.2008-0013).

DISTRIBUTION. — New Caledonia waters from 18°59.93’S, 163°13.55’E to 24°45’S, 168°07’E, Loyalty islands ( Gardiner 1899), 73- 400 m. Previous records: Australia off Queensland ( Cairns 1995), 315-360 m; Wallis and Futuna region, and Vanuatu region (Cairns 1999), 295- 360 m.

DESCRIPTION

Corallum circular, lancetted and shaped as a shallow bowl with upturned edges. Base flat to slightly concave, sometimes with small scar at centre. C1-2 equal and always reach centre of base, being separated from adjacent costae by moderately deep intercostal furrows. C3 most developed costae projecting up to 1.5 mm beyond calicular edge as 12 granular spines. C4 do not reach centre of base, but fuses adjacent C3 beyond calicular margin producing 12 well-developed apexes. Corallum white.

Septa hexamerally arranged in 4 cycles (S1>S2> S4>S3). S1 only independent septa, extending ¾ the distance to columella, being separated from their dimorphic paliform lobe (as in D. crassiseptum ) by a deep notch. S2 slightly narrower than S1 and bear a small palus. S3 are smallest septa (⅓ of S2) but bears largest paliform lobes which fuse P2 near columella. S4 fuses outer edge of flanked P3.

Fossa shallow containing an elliptical papillose columella aligned with the two principal S1. Columella consists of small, short, fused tuberculate papillae.

REMARKS

Among the five-spined species of Deltocyathus , three occur in New Caledonian waters: D. ornatus , D.heteroclitus , and D. corrugatus . Deltocyathus ornatus and D. corrugatus are easily separated from D. heteroclitus using the number of spines present:12 versus 6-8 in D. heteroclitus , and the P1 dimorphism: dimorphic in D. ornatus and D. corrugatus and not dimorphic in D. heteroclitus . However,the differences between the other two species with 12 spines that occur in New Caledonia region are very subtle: D. corrugatus usually possesses a circular basal scar, C3 very proeminent, and longer and slender costal spines (also see Cairns 1999).