Deltocyathus cameratus

biology_ecology

Substrate type: The specimen collected from the medium-grained basalt covered by a thick Fe-Mn crust in the ridge system indicates a geological environment typical of mid-ocean ridges.

Deep-sea corals from the seamounts of Central and Southwest Indian Ridges

description

Description: Corallum shaped as a shallow bowl, with a slightly convex base, 10.8 mm in calicular diameter and 4.2 mm in height. Calice circular with a jagged margin. C 3 and adjacent pair of C 4 project outward as small triangular to rectangular lancets. Intercostal grooves prominent at calicular edge and coarsely pointed spines; intercostals grooves between C 3 and C 4 shallower than others; C 1 and C 2 start at centre of the base; C 4 smaller compared with C 3. Conical shape base. Corallum white. Septa hexamerally arranged in four complete cycles (S 1> S 2> S 4> S 3). S 1 only independent septa, 1.5 mm exsert, and reach 1 / 2 distance to columella. Each S 1 possesses a lamellar paliform lobe that encircles the columella, creating the first palar crown. S 2 less wide and exsert than S 1. S 3 smallest septa but have the tallest pali. Each S 3 fuses to flanking S 2 in acute lamellar structure (Fig. 4 A). S 4 less exsert but slightly wider than S 3. Each pair of S 4 fuses flanked S 3 with a porous lamella that extend lower in theca almost to columella. All septa uniformly thin and have straight axial margins. Every septa and palar face roughly granulated. P 1 - 3 uniform in width, a

Deep-sea corals from the seamounts of Central and Southwest Indian Ridges

discussion

Remarks: In comparison to the other four non-spined Deltocyathus species as described by Kitahara & Cairns (2009), the CIR specimen has well-developed lamellar fusions of the S 4 to P 3 and P 3 to P 2, a lancetted calicular margin, and the corallum is divided into 24 elliptical chambers.

Deep-sea corals from the seamounts of Central and Southwest Indian Ridges

distribution

Distribution: Previously documented in the Pacific Ocean, this species has been reported from the Wallis and Futuna region at depths ranging from 707 to 777 m (Kitahara & Cairns 2009), in the Vanuatu region at depths of 305 to 1010 m (Cairns 1999), and other various locations, including the Lord Howe Rise, Elizabeth Reef, and Britannia at depths of 512 to 1175 m (Cairns 2004). It has also been recorded in Erromango and Malakula at depths ranging from 419 to 1078 m (Cairns 2004). The new record reported herein extends its distribution to the CIR at a depth of 2007 m.

Deep-sea corals from the seamounts of Central and Southwest Indian Ridges