taxonID	type	description	language	source
1D15F50FFFF62326FF68FCC4FE48965F.taxon	description	(Figs 2 A – E)	en	Periasamy, Rengaiyan, Kurian, Palayil John, Ingole, Baban (2025): Deep-sea corals from the seamounts of Central and Southwest Indian Ridges. Zootaxa 5620 (2): 278-294, DOI: 10.11646/zootaxa.5620.2.4, URL: https://doi.org/10.11646/zootaxa.5620.2.4
1D15F50FFFF62326FF68FCC4FE48965F.taxon	materials_examined	Material examined: One colony (NCPOR / HYD-CIR / 0044), Central Indian Ridge: R / V MGS Sagar, stn. MGS 35 A _ BD 9, 23 ° 10 ' 01 '' S, 69 ° 31 ' 49 '' E, 2103 m, 20.04.2020.	en	Periasamy, Rengaiyan, Kurian, Palayil John, Ingole, Baban (2025): Deep-sea corals from the seamounts of Central and Southwest Indian Ridges. Zootaxa 5620 (2): 278-294, DOI: 10.11646/zootaxa.5620.2.4, URL: https://doi.org/10.11646/zootaxa.5620.2.4
1D15F50FFFF62326FF68FCC4FE48965F.taxon	description	Description: Small colony, fragile, flabellate, 18 mm high and 13 mm wide; branch base 1 – 1.2 mm diameter; distal branches about 0.37 – 0.4 mm in diameter. Dichotomous branching support cyclosystems; one branch of dichotomy usually developed as a small nub; distal branches create sympodial pattern of budding; white coenosteum consists of parallel, convex cords, a width of cords ranged from 52 – 100 µm with slight grooves. Round to slightly elliptical cyclosystems 2.5 – 1.5 mm in diameter. Cyclosystems present on anterior side and raised somewhat on top of branch ~ 0.5 mm; flared predicles; 12 – 19 dactylopores per cyclosystem; dactylotomes 95 – 105 µm wide; broaden midway to base of gastropore; triangular pseudosepta up to 0.2 mm wide at external edge of cyclosystem. Every pseudoseptum tapers to apex to about 0.03 mm width. Narrow inner edges of pseudosepta in front of gastropore straight and vertical with somewhat concave upper faces (Fig. 2 B).	en	Periasamy, Rengaiyan, Kurian, Palayil John, Ingole, Baban (2025): Deep-sea corals from the seamounts of Central and Southwest Indian Ridges. Zootaxa 5620 (2): 278-294, DOI: 10.11646/zootaxa.5620.2.4, URL: https://doi.org/10.11646/zootaxa.5620.2.4
1D15F50FFFF62326FF68FCC4FE48965F.taxon	discussion	Remarks: The specimen from the CIR resembles Crypthelia fragilis Cairns, 1983 due to its round cyclosystems and triangular pseudosepta with concave upper edges. Additionally, the lid may be present as a narrow concave tongue. C. fragilis has previously been documented only in the Subantarctic region, at depths ranging from 952 to 2329 m. However, the identification of the CIR specimen remains inconclusive due to the absence of male or female ampullae.	en	Periasamy, Rengaiyan, Kurian, Palayil John, Ingole, Baban (2025): Deep-sea corals from the seamounts of Central and Southwest Indian Ridges. Zootaxa 5620 (2): 278-294, DOI: 10.11646/zootaxa.5620.2.4, URL: https://doi.org/10.11646/zootaxa.5620.2.4
1D15F50FFFF62326FF68FCC4FE48965F.taxon	biology_ecology	Substrate type: The specimen was collected from the medium-grained basalt in the CIR ridge system. The basalt substrate provides a habitat for benthic fauna, which can colonize these rocky surfaces. As primary colonizers in harsh environments, these organisms often play important roles in the deep-sea ecosystem.	en	Periasamy, Rengaiyan, Kurian, Palayil John, Ingole, Baban (2025): Deep-sea corals from the seamounts of Central and Southwest Indian Ridges. Zootaxa 5620 (2): 278-294, DOI: 10.11646/zootaxa.5620.2.4, URL: https://doi.org/10.11646/zootaxa.5620.2.4
1D15F50FFFF62326FF68FCC4FE48965F.taxon	distribution	Distribution: The genus Crypthelia, with 47 recognized species, is distributed across all three major ocean basins (Schuchert 2024).	en	Periasamy, Rengaiyan, Kurian, Palayil John, Ingole, Baban (2025): Deep-sea corals from the seamounts of Central and Southwest Indian Ridges. Zootaxa 5620 (2): 278-294, DOI: 10.11646/zootaxa.5620.2.4, URL: https://doi.org/10.11646/zootaxa.5620.2.4
1D15F50FFFF62320FF68F924FF389283.taxon	description	(Figs. 2 F – J)	en	Periasamy, Rengaiyan, Kurian, Palayil John, Ingole, Baban (2025): Deep-sea corals from the seamounts of Central and Southwest Indian Ridges. Zootaxa 5620 (2): 278-294, DOI: 10.11646/zootaxa.5620.2.4, URL: https://doi.org/10.11646/zootaxa.5620.2.4
1D15F50FFFF62320FF68F924FF389283.taxon	materials_examined	Material examined: One colony (NCPOR / HYD-CIR / 0045), Central Indian Ridge: R / V MGS Sagar, stn. MGS 35 A _ BD 9, 23 ° 10 ' 01 '' S, 69 ° 31 ' 49 '' E, 2103 m, 20 th April 2020.	en	Periasamy, Rengaiyan, Kurian, Palayil John, Ingole, Baban (2025): Deep-sea corals from the seamounts of Central and Southwest Indian Ridges. Zootaxa 5620 (2): 278-294, DOI: 10.11646/zootaxa.5620.2.4, URL: https://doi.org/10.11646/zootaxa.5620.2.4
1D15F50FFFF62320FF68F924FF389283.taxon	description	Description: Colony uniplanar with 9.23 mm tall and 1.5 mm wide, delicate anastomosing branches. Distal branches 0.42 mm in diameter; base of branch 0.9 mm diameter. Coenosteal texture linear-imbricate strips width of 37 – 51 µm; ridged and rough platelets. Circular-shaped cyclosystems, with 1 – 1.4 mm in diameter; 13 – 16 dactylopores per cyclosystem. Cup-shaped upper gastropore tube about 0.28 µm in diameter covered with linear-imbricate coenosteum. Ring constraint about 0.12 – 0.14 mm in diameter and tubular; about 80 µm in length; with a crescent-shaped lower chamber about 0.40 mm wide. Tip projects through ring constriction in the center of lower chamber as a triangular gastrostyle. Most cyclosystems have no lid, but many have an abcauline pseudoseptum enlarged to 2 – 3 times width of a typical pseudoseptum. Narrow dactylotomes, not descending into gastropore very far; broad and concave pseudosepta; uniformly white colour (Fig. 2 F).	en	Periasamy, Rengaiyan, Kurian, Palayil John, Ingole, Baban (2025): Deep-sea corals from the seamounts of Central and Southwest Indian Ridges. Zootaxa 5620 (2): 278-294, DOI: 10.11646/zootaxa.5620.2.4, URL: https://doi.org/10.11646/zootaxa.5620.2.4
1D15F50FFFF62320FF68F924FF389283.taxon	discussion	Remarks: Pseudocrypthelia is closely related to the genus Crypthelia but is distinguished by having a rudimentary gastrostyle. The genus Pseudocrypthelia comprises P. pachypoma (Hickson & England 1905) and P. apoma, both native to the New Caledonian region. While P. apoma and P. pachypoma are similar in terms of their colony shape, coenosteal texture, nematopore placement, and pseudoseptal shape (Cairns 2015), they differ in several key aspects: P. apoma lacks a cyclosystem lid. P. apoma has a markedly different placement of its female and male ampullae. The placement of the female efferent pores also differs significantly between the two species. These differences in reproductive structures and the presence or absence of the cyclosystem lid are the primary distinguishing characteristics between the two species within the genus Pseudocrypthelia.	en	Periasamy, Rengaiyan, Kurian, Palayil John, Ingole, Baban (2025): Deep-sea corals from the seamounts of Central and Southwest Indian Ridges. Zootaxa 5620 (2): 278-294, DOI: 10.11646/zootaxa.5620.2.4, URL: https://doi.org/10.11646/zootaxa.5620.2.4
1D15F50FFFF62320FF68F924FF389283.taxon	biology_ecology	Substrate type: The specimen was collected from the medium-grained basalt in the CIR ridge system.	en	Periasamy, Rengaiyan, Kurian, Palayil John, Ingole, Baban (2025): Deep-sea corals from the seamounts of Central and Southwest Indian Ridges. Zootaxa 5620 (2): 278-294, DOI: 10.11646/zootaxa.5620.2.4, URL: https://doi.org/10.11646/zootaxa.5620.2.4
1D15F50FFFF62320FF68F924FF389283.taxon	distribution	Distribution: Pseudocrypthelia apoma is distributed in several regions around New Caledonia, including the Grand Passage, Loyalty Islands, and Northern Norfolk Ridge, at depths ranging from 235 to 502 m (Cairns 2015). Herein, we register this species to the CIR at a much greater depth of 2103 m, significantly extending its known range.	en	Periasamy, Rengaiyan, Kurian, Palayil John, Ingole, Baban (2025): Deep-sea corals from the seamounts of Central and Southwest Indian Ridges. Zootaxa 5620 (2): 278-294, DOI: 10.11646/zootaxa.5620.2.4, URL: https://doi.org/10.11646/zootaxa.5620.2.4
1D15F50FFFF02323FF60FB71FBD890D3.taxon	description	(Figs. 3 A – C)	en	Periasamy, Rengaiyan, Kurian, Palayil John, Ingole, Baban (2025): Deep-sea corals from the seamounts of Central and Southwest Indian Ridges. Zootaxa 5620 (2): 278-294, DOI: 10.11646/zootaxa.5620.2.4, URL: https://doi.org/10.11646/zootaxa.5620.2.4
1D15F50FFFF02323FF60FB71FBD890D3.taxon	materials_examined	Material examined: One specimen (NCPOR / HYD-SWIR / 0028), Southwest Indian Ridge system, R / V MGS Sagar, stn. MGS 25 _ DRG 12, 26 ° 49 ' 47 " S; 67 ° 40 ' 46 " E, 1641 m, 10 th April 2019.	en	Periasamy, Rengaiyan, Kurian, Palayil John, Ingole, Baban (2025): Deep-sea corals from the seamounts of Central and Southwest Indian Ridges. Zootaxa 5620 (2): 278-294, DOI: 10.11646/zootaxa.5620.2.4, URL: https://doi.org/10.11646/zootaxa.5620.2.4
1D15F50FFFF02323FF60FB71FBD890D3.taxon	description	Description: Corallum ceratoid, attached, tapering to a slightly curved and slender pedicel. Calice slightly elliptical in shape with a lancet-shaped calicular edge. Hexamerally arranged septa in four complete cycles (formula: S 1 ≥ S 2> S 3> S 4 - 48 septa). S 1 equal to or slightly higher, wide and exsert than S 2 (Fig. 3 A); those of third cycle larger and a little more exsert than S 4, with a sinuous axial margin bearing a large sinuous pali. Axial edge of S 1 somewhat sinuous. S 3 less exsert than S 1 – S 2; S 4 joins S 1 - 2 and creates a lanceted calicular marginal. Columella deep-seated. All septa and pali covered in granules. Corallum white with faint brownish-pink tinge near calicular margin (Figs. 3 A – C).	en	Periasamy, Rengaiyan, Kurian, Palayil John, Ingole, Baban (2025): Deep-sea corals from the seamounts of Central and Southwest Indian Ridges. Zootaxa 5620 (2): 278-294, DOI: 10.11646/zootaxa.5620.2.4, URL: https://doi.org/10.11646/zootaxa.5620.2.4
1D15F50FFFF02323FF60FB71FBD890D3.taxon	discussion	Remarks: Caryophyllia (C.) ephyala belongs to the largest morphological group within the genus Caryophyllia (Cairns et al. 2005), characterized by septa hexamerally arranged in four complete cycles. However, it is notable that the septa of the SWIR specimen exhibit a broader and more lanceted calicular margin compared to those described by Alcock (1891), Gardiner (1904), and Filander et al. (2021).	en	Periasamy, Rengaiyan, Kurian, Palayil John, Ingole, Baban (2025): Deep-sea corals from the seamounts of Central and Southwest Indian Ridges. Zootaxa 5620 (2): 278-294, DOI: 10.11646/zootaxa.5620.2.4, URL: https://doi.org/10.11646/zootaxa.5620.2.4
1D15F50FFFF02323FF60FB71FBD890D3.taxon	biology_ecology	Substrate type: The specimen collected from medium-grained basalt in the SWIR ridge system indicates a habitat that supports benthic fauna, which colonize rocky surfaces. These organisms serve as primary colonizers in harsh deep-sea environments, playing crucial roles in the ecosystem dynamics of the ocean floor.	en	Periasamy, Rengaiyan, Kurian, Palayil John, Ingole, Baban (2025): Deep-sea corals from the seamounts of Central and Southwest Indian Ridges. Zootaxa 5620 (2): 278-294, DOI: 10.11646/zootaxa.5620.2.4, URL: https://doi.org/10.11646/zootaxa.5620.2.4
1D15F50FFFF02323FF60FB71FBD890D3.taxon	distribution	Distribution: Off the western margin of the Andaman Sea, Bay of Bengal, India (HMS ‘ Investigator’ stn. 56) at a depth 439 – 402 m (Alcock 1891); Western and eastern margin of South Africa (Gardiner 1904), 146 – 567 m; Japan (Yabe & Eguchi 1932), 146 – 1289 m (Cairns & Keller 1993). C. (C.) ephyala have recently been identified in the Brak Estuary of South Africa at 440 m (Filander et al. 2021). The examined specimen of C. (C.) ephyala expands the known distribution to the seamounts of the SWIR at a deeper region of 1641 m.	en	Periasamy, Rengaiyan, Kurian, Palayil John, Ingole, Baban (2025): Deep-sea corals from the seamounts of Central and Southwest Indian Ridges. Zootaxa 5620 (2): 278-294, DOI: 10.11646/zootaxa.5620.2.4, URL: https://doi.org/10.11646/zootaxa.5620.2.4
1D15F50FFFF22322FF68FEC7FD2294D9.taxon	description	(Figs. 3 D – F)	en	Periasamy, Rengaiyan, Kurian, Palayil John, Ingole, Baban (2025): Deep-sea corals from the seamounts of Central and Southwest Indian Ridges. Zootaxa 5620 (2): 278-294, DOI: 10.11646/zootaxa.5620.2.4, URL: https://doi.org/10.11646/zootaxa.5620.2.4
1D15F50FFFF22322FF68FEC7FD2294D9.taxon	materials_examined	Material examined: One specimen (NCPOR / HYD-CIR / 0029), Central Indian Ridge: R / V MGS Sagar, stn. MGS 35 A _ BD 9, 23 ° 10 ' 01 '' S, 69 ° 31 ' 49 '' E, 2103 m, 20 th April 2020.	en	Periasamy, Rengaiyan, Kurian, Palayil John, Ingole, Baban (2025): Deep-sea corals from the seamounts of Central and Southwest Indian Ridges. Zootaxa 5620 (2): 278-294, DOI: 10.11646/zootaxa.5620.2.4, URL: https://doi.org/10.11646/zootaxa.5620.2.4
1D15F50FFFF22322FF68FEC7FD2294D9.taxon	description	Description: Corallum short and patelliform in shape; base attached to a solid substrate (Fig. 3 D). Examined specimen 15 x 13.2 mm in calicular diameter, 3.3 mm in pedicel diameter, 7.0 mm in height; costae distinct, rounded, and covered with fine, spiny granules (Fig. 3 F). At lower corallum intercostal grooves as wide as costae but deeper and broader near the calicular edge. Corallum white. Septa hexamerally arranged in 5 incomplete cycles according to the formula: S 1 – S 2> S 3> S 4> S 5. Septa cycle contains 12 pairs of inserted S 5 half-systems with two pairs of S 5 and two half-systems having one pair of S 5; for a total of 69 septa (Fig. 3 E). S 1 – 2 relatively large and exsert, and having axial edges straight and granular faces. Septal faces covered with spiny granules. S 1 quite large, each having a straight axial edge that meet columella, moderately sinuous peripheral edge; separated from the similar septum by a small notch. S 3 – S 4 less exsert. P 2 – P 4 about 1.8 mm wide. Each cycle becomes increasingly more concave from columella and rises slightly higher in fossa. Fossa shallow. Columella composed of several finely granulated massive papillae fused into an irregular, elongated mass (Figs. 3 D, E).	en	Periasamy, Rengaiyan, Kurian, Palayil John, Ingole, Baban (2025): Deep-sea corals from the seamounts of Central and Southwest Indian Ridges. Zootaxa 5620 (2): 278-294, DOI: 10.11646/zootaxa.5620.2.4, URL: https://doi.org/10.11646/zootaxa.5620.2.4
1D15F50FFFF22322FF68FEC7FD2294D9.taxon	discussion	Remarks: Trochocyathus (T.) patelliformis is unique within the genus in having a patellate-shaped corallum with P 1 being significantly broader than the higher cycle pali, and finely spinose costae. However, the Central Indian Ridge (CIR) specimen differs slightly in that it has a circular shape of the columella, whereas the columella in the specimen described by Cairns (1999) is elongated.	en	Periasamy, Rengaiyan, Kurian, Palayil John, Ingole, Baban (2025): Deep-sea corals from the seamounts of Central and Southwest Indian Ridges. Zootaxa 5620 (2): 278-294, DOI: 10.11646/zootaxa.5620.2.4, URL: https://doi.org/10.11646/zootaxa.5620.2.4
1D15F50FFFF22322FF68FEC7FD2294D9.taxon	biology_ecology	Substrate type: The specimen collected from gabbro, ultramafic rock, and oolitic sand in the ridge system indicates a complex geological environment.	en	Periasamy, Rengaiyan, Kurian, Palayil John, Ingole, Baban (2025): Deep-sea corals from the seamounts of Central and Southwest Indian Ridges. Zootaxa 5620 (2): 278-294, DOI: 10.11646/zootaxa.5620.2.4, URL: https://doi.org/10.11646/zootaxa.5620.2.4
1D15F50FFFF22322FF68FEC7FD2294D9.taxon	distribution	Distribution: Previously recorded in the Hawaiian Islands, the South Pacific, and the Vanuatu region at depths of 1010 – 1750 m and in Espíritu Santo between 1210 – 1250 m (Cairns 1999). The distribution of this species is now extended to include the CIR at a depth of 2103 m.	en	Periasamy, Rengaiyan, Kurian, Palayil John, Ingole, Baban (2025): Deep-sea corals from the seamounts of Central and Southwest Indian Ridges. Zootaxa 5620 (2): 278-294, DOI: 10.11646/zootaxa.5620.2.4, URL: https://doi.org/10.11646/zootaxa.5620.2.4
1D15F50FFFF2232DFF68FA64FF16933F.taxon	description	(Figs. 4 A – C)	en	Periasamy, Rengaiyan, Kurian, Palayil John, Ingole, Baban (2025): Deep-sea corals from the seamounts of Central and Southwest Indian Ridges. Zootaxa 5620 (2): 278-294, DOI: 10.11646/zootaxa.5620.2.4, URL: https://doi.org/10.11646/zootaxa.5620.2.4
1D15F50FFFF2232DFF68FA64FF16933F.taxon	materials_examined	Material examined: One specimen (NCPOR / HYD-CIR / 0027), Central Indian Ridge: R / V MGS Sagar, stn. MGS 35 A _ D 11, 23 ° 11 ' 25 '' S; 69 ° 32 ' 51 '' E, 2007 m, 15 th April 2020.	en	Periasamy, Rengaiyan, Kurian, Palayil John, Ingole, Baban (2025): Deep-sea corals from the seamounts of Central and Southwest Indian Ridges. Zootaxa 5620 (2): 278-294, DOI: 10.11646/zootaxa.5620.2.4, URL: https://doi.org/10.11646/zootaxa.5620.2.4
1D15F50FFFF2232DFF68FA64FF16933F.taxon	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, and separated from their corresponding septa by wide notches. Axial edges of P 1 and P 2 merge to columella, even though P 2 rise slightly higher in fossa. Axial edges of every pair of P 3 strongly fused to their adjacent P 2; this fusion being imperforate and reaching as high as S 3 – P 3 notch. Fossa shallow to nonextant with a well-developed papillose columella formed by 10 – 15 robust and granular rods (Figs. 4 A – C).	en	Periasamy, Rengaiyan, Kurian, Palayil John, Ingole, Baban (2025): Deep-sea corals from the seamounts of Central and Southwest Indian Ridges. Zootaxa 5620 (2): 278-294, DOI: 10.11646/zootaxa.5620.2.4, URL: https://doi.org/10.11646/zootaxa.5620.2.4
1D15F50FFFF2232DFF68FA64FF16933F.taxon	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.	en	Periasamy, Rengaiyan, Kurian, Palayil John, Ingole, Baban (2025): Deep-sea corals from the seamounts of Central and Southwest Indian Ridges. Zootaxa 5620 (2): 278-294, DOI: 10.11646/zootaxa.5620.2.4, URL: https://doi.org/10.11646/zootaxa.5620.2.4
1D15F50FFFF2232DFF68FA64FF16933F.taxon	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.	en	Periasamy, Rengaiyan, Kurian, Palayil John, Ingole, Baban (2025): Deep-sea corals from the seamounts of Central and Southwest Indian Ridges. Zootaxa 5620 (2): 278-294, DOI: 10.11646/zootaxa.5620.2.4, URL: https://doi.org/10.11646/zootaxa.5620.2.4
1D15F50FFFF2232DFF68FA64FF16933F.taxon	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.	en	Periasamy, Rengaiyan, Kurian, Palayil John, Ingole, Baban (2025): Deep-sea corals from the seamounts of Central and Southwest Indian Ridges. Zootaxa 5620 (2): 278-294, DOI: 10.11646/zootaxa.5620.2.4, URL: https://doi.org/10.11646/zootaxa.5620.2.4
1D15F50FFFFD232FFF68F941FC409377.taxon	description	(Figs. 5 A – F)	en	Periasamy, Rengaiyan, Kurian, Palayil John, Ingole, Baban (2025): Deep-sea corals from the seamounts of Central and Southwest Indian Ridges. Zootaxa 5620 (2): 278-294, DOI: 10.11646/zootaxa.5620.2.4, URL: https://doi.org/10.11646/zootaxa.5620.2.4
1D15F50FFFFD232FFF68F941FC409377.taxon	materials_examined	Material examined: One colony (NCPOR / HYD-CIR / 0047), Central Indian Ridge: R / V MGS Sagar, stn. MGS 35 A-BD 22), 23 ° 11 ' 14 '' S, 69 ° 33 ' 9 '' E, 2005 m, 23 rd April 2020.	en	Periasamy, Rengaiyan, Kurian, Palayil John, Ingole, Baban (2025): Deep-sea corals from the seamounts of Central and Southwest Indian Ridges. Zootaxa 5620 (2): 278-294, DOI: 10.11646/zootaxa.5620.2.4, URL: https://doi.org/10.11646/zootaxa.5620.2.4
1D15F50FFFFD232FFF68F941FC409377.taxon	description	Description: Colony unbranched, flagelliform (whip-like or bottlebrush), and up to 15.3 cm in length and 1.4 mm in width; central axis hard and golden in color. Polyps stand perpendicular polyps to the stem, arranged in a spiral, many polyps with cylindrical about 3.2 – 3.5 mm in height including spines, arranged in whorls of four or five polyps, the lesser number toward the branch tip. Marginal, opercular, body wall, and coenenchymal scales have a smooth outer, inner surfaces covered by tuberculate. Marginal and submarginal scales cover a polyp and those closest to the operculum, an elongated apical spine that does not fold over the operculum. Opercular scales blunt, elongated apical spines, tongue-shaped, highly concave in the outer surface, blunt tip without non-spinose, 0.8 – 0.95 mm in length, base scales 0.32 – 0.54 mm in width. Body wall scale arranged in eight longitudinal rows, with each row having 7 – 10 scales. Coenenchymal scale smaller, smooth outer surface, more irregular in shape and like those of body wall, arranged in one thin layer, inner surface covered with a thick layer of tuberculate on base region 0.15 – 0.35 mm in diameter (Figs. 5 A – F).	en	Periasamy, Rengaiyan, Kurian, Palayil John, Ingole, Baban (2025): Deep-sea corals from the seamounts of Central and Southwest Indian Ridges. Zootaxa 5620 (2): 278-294, DOI: 10.11646/zootaxa.5620.2.4, URL: https://doi.org/10.11646/zootaxa.5620.2.4
1D15F50FFFFD232FFF68F941FC409377.taxon	discussion	Remark: The CIR specimen features tightly compressed whorls with well-developed axes, as described by Bayer (1996), Cairns & Bayer (2009), and Cairns (2016). Callozostron contains six species and is commonly found in deep water (bathyal abyss). Bayer (1996) identified the four Callozostron species that existed at the time, whereas Cairns (2015, 2016) described two new species. C. mirabile was found to be deeper than 3000 m in the CIR. Substrate type: The specimen collected from highly altered basalt in the ridge system indicates a geological environment where the original basalt has undergone significant changes due to weathering, hydrothermal alteration, or chemical reactions with seawater.	en	Periasamy, Rengaiyan, Kurian, Palayil John, Ingole, Baban (2025): Deep-sea corals from the seamounts of Central and Southwest Indian Ridges. Zootaxa 5620 (2): 278-294, DOI: 10.11646/zootaxa.5620.2.4, URL: https://doi.org/10.11646/zootaxa.5620.2.4
1D15F50FFFFD232FFF68F941FC409377.taxon	distribution	Distribution: This species is previously known from the Southern Ocean, Antarctic Oates coast (2836 to 2864), South Atlantic Ocean (2653 to 2941), and North Island (New Zealand) (1354 to 3876). Notably, it has now been identified for the first time in the CIR at a depth of 2005 m. Molecular data: The pairwise distance between Callozostron mirabile from the CIR (OM 472571) and New Zealand (MG 986927) is 0.9 to 1.0 % with other Callozostron species. The low pairwise distance suggested closely related species, indicating a relatively close evolutionary relationship.	en	Periasamy, Rengaiyan, Kurian, Palayil John, Ingole, Baban (2025): Deep-sea corals from the seamounts of Central and Southwest Indian Ridges. Zootaxa 5620 (2): 278-294, DOI: 10.11646/zootaxa.5620.2.4, URL: https://doi.org/10.11646/zootaxa.5620.2.4
1D15F50FFFFF232EFF68FC2CFCEE916B.taxon	materials_examined	Material examined: One colony (NCPOR / HYD-SWIR / 0046), Southwest Indian Ridge, MGS 25 cruise, R / V MGS Sagar, stn. MGS 35 E – D 1, 28 ° 03 ' 18 '' S, 63 ° 35 ' 49 '' E, 3551 m, 22 nd March 2020.	en	Periasamy, Rengaiyan, Kurian, Palayil John, Ingole, Baban (2025): Deep-sea corals from the seamounts of Central and Southwest Indian Ridges. Zootaxa 5620 (2): 278-294, DOI: 10.11646/zootaxa.5620.2.4, URL: https://doi.org/10.11646/zootaxa.5620.2.4
1D15F50FFFFF232EFF68FC2CFCEE916B.taxon	description	Description: Colony delicate, uniplanar, axis pale yellow. Polyps paired, about four pairs occurring every cm of branch length, curved upward (Figs. 6 A, B). Primary polyps larger, body wall sclerite formula 4 – 7: 3 – 4: 3 – 4: 3 – 4. Opercular scales triangular to a narrow oval shape tapering to a point like lanceolate; long and slender (L: W = 2.3 – 3.2); 0.8 – 0.85 mm in length, longitudinally concave, smooth outer surface; tuberculate inner distal surface for attachment; multiple-keeled inner proximal surface. Body wall scales flat to slightly concave, rounded proximal edge. Marginal scales keeled, smooth, width 0.21 – 0.28 mm; distal body wall scales the width of 0.6 – 0.6 mm. Body wall scales flat and smooth outer surface, inner surface covered with low tubercles, except for the proximal margin about 40 – 50 µm in width. Coenenchymal scales trapezoidal to rectangular, smooth outer surface, tuberculate inner surface, they are a little smaller than the body wall scales, averaging ~ 0.20 – 0.24 mm in width, arranged in a linearly imbricate fashion (Figs. 6 A – E).	en	Periasamy, Rengaiyan, Kurian, Palayil John, Ingole, Baban (2025): Deep-sea corals from the seamounts of Central and Southwest Indian Ridges. Zootaxa 5620 (2): 278-294, DOI: 10.11646/zootaxa.5620.2.4, URL: https://doi.org/10.11646/zootaxa.5620.2.4
1D15F50FFFFF232EFF68FC2CFCEE916B.taxon	discussion	Remarks: The identification of the specimen agrees with the previous descriptions by Thomson & Rennett (1931), Cairns & Bayer (2009), Zapata-Guardiola, López González & Gili (2012), and Cairns (2016). F. delicatula is distinguished morphologically from F. abietina by its fragile, uniplanar, pinnate colony structure, a base branch approximately 0.2 mm in diameter, alternate paired polyps, a pale yellow main axis, about four pairs of polyps per centimeter along the branch, upward-curving polyps with 1.2 - 1.5 mm in length, and a subtly flared distal end.	en	Periasamy, Rengaiyan, Kurian, Palayil John, Ingole, Baban (2025): Deep-sea corals from the seamounts of Central and Southwest Indian Ridges. Zootaxa 5620 (2): 278-294, DOI: 10.11646/zootaxa.5620.2.4, URL: https://doi.org/10.11646/zootaxa.5620.2.4
1D15F50FFFFF232EFF68FC2CFCEE916B.taxon	biology_ecology	Substrate type: The specimen collected from highly altered ultramafic rock covered by a thick Fe-Mn crust in the ridge system suggests a geological environment where ultramafic rock, rich in magnesium and iron, have undergone substantial alteration, likely due to hydrothermal processes.	en	Periasamy, Rengaiyan, Kurian, Palayil John, Ingole, Baban (2025): Deep-sea corals from the seamounts of Central and Southwest Indian Ridges. Zootaxa 5620 (2): 278-294, DOI: 10.11646/zootaxa.5620.2.4, URL: https://doi.org/10.11646/zootaxa.5620.2.4
1D15F50FFFFF232EFF68FC2CFCEE916B.taxon	distribution	Distribution: The type locality of this species was from off Macquarie Island, Australian EEZ, at 2743 m (Thomson & Rennet 1931); also found in the east of Pitt Island and the Bay of Plenty, North Island at depths ranging from 520 to 2743 m; Chatham Rise, Iceberg Seamount at 520 – 650 m (Cairns 2016). The F. delicatula from the SWIR has been recorded for the first time at a deeper depth of 3551 m.	en	Periasamy, Rengaiyan, Kurian, Palayil John, Ingole, Baban (2025): Deep-sea corals from the seamounts of Central and Southwest Indian Ridges. Zootaxa 5620 (2): 278-294, DOI: 10.11646/zootaxa.5620.2.4, URL: https://doi.org/10.11646/zootaxa.5620.2.4
1D15F50FFFFF232EFF68FC2CFCEE916B.taxon	description	Molecular data: The pairwise distance between Faxiella delicatula species from the SWIR (OM 472570) and those from New Zealand (MG 986958, Cairns & Wirshing 2018) is 2.1 %. The high distance value indicates that these populations are probably isolated from each other.	en	Periasamy, Rengaiyan, Kurian, Palayil John, Ingole, Baban (2025): Deep-sea corals from the seamounts of Central and Southwest Indian Ridges. Zootaxa 5620 (2): 278-294, DOI: 10.11646/zootaxa.5620.2.4, URL: https://doi.org/10.11646/zootaxa.5620.2.4
