Telestula ridgensis, Periasamy & Kurian & Ingole, 2023

Periasamy, Rengaiyan, Kurian, Palayil John & Ingole, Baban, 2023, A new deep-water coral species Telestula ridgensis sp. nov (Scleralcyonacea: Sarcodictyonidae) from the seamount of theCentral Indian Ridge, Zootaxa 5254 (2), pp. 231-244 : 233-238

publication ID	https://doi.org/ 10.11646/zootaxa.5254.2.4
publication LSID	lsid:zoobank.org:pub:AF9325A8-00A5-4D40-B16C-F983A585CF19
DOI	https://doi.org/10.5281/zenodo.7733356
persistent identifier	https://treatment.plazi.org/id/039D87B2-F359-FFB2-4586-FE41FBD69C40
treatment provided by	Plazi
scientific name	Telestula ridgensis
status	sp. nov.

Treatment

Telestula ridgensis sp. nov.

Figs 1–8 View FIGURE 1 View FIGURE 2 View FIGURE 3 View FIGURE 4 View FIGURE 5 View FIGURE 6 View FIGURE 7 View FIGURE 8

Type material: holotype: Specimen , NCPOR /HYD-CIR/0048, Seamount of the Central Indian Ridge , Indian Ocean, R / V ‘ MGS Sagar’ cruise MGS–35 (Station MGS-35A-BD21), 24 April 2020, 23°10′28.92′′ S, 69°32′47.04′′ E, 1917 to 2053 m, Benthic Sledge, Coll. Periasamy R, samples in 90% ethanol GoogleMaps .

Paratypes: One specimen NCPOR /HYD-CIR/0049 from the same locality as the holotype GoogleMaps .

Ecological note: The specimen was collected along with two types of carnivorous sponges; three types of deepsea coral, three types of brittle stars, shrimps; and dead gastropod shells from medium-grained basalt rocky bottom with thick Fe-Mn crust.

Coloration: The color of colonies ranges from yellowish-brown to dark brown or black; with their ends forming white or cream polyps.

Distribution: Telestula ridgensis sp. nov. is known only for its type locality in the seamounts of the Central Indian Ridge system.

Etymology: The specific name refers to the type locality of the Indian Ocean Ridge. Gender is feminine.

Description

Coral colonies are inter-connected with polyps by ribbon - like stolon expanding in irregular patterns on the surface of a dead coral ( Fig. 2A View FIGURE 2 ), and budding of secondary polyps ( Fig. 2C View FIGURE 2 ). The polyps arise from a ribbon - like stolon (0.6 mm in width).

The holotype is about 19.7 mm tall and 0.2 mm in diameter, with eight polyps attached ( Fig. 2D View FIGURE 2 ). Fully retracted polyps are up to 12 mm in height and 1.5 mm in width.

Sclerites in the polyp ( Fig. 3A,B,C View FIGURE 3 ) form a thick layer in the calyx wall region, being longitudinally arranged and tightly packed ( Fig. 3D View FIGURE 3 ). The stolon is ribbon-shaped, with sclerites longitudinally arranged along the thin basal stolon ( Fig. 3E View FIGURE 3 ). The sclerites in the tentacles and middle of the neck zone are transversely set ( Fig. 4A, B,C View FIGURE 4 ).

Tentacles sclerites are narrow and stellate plates; cross-like forms with slightly tubercular ornamentation; stellate plates (0.19– 0.06 mm long 0.08– 0.02 mm wide); cross-like sclerites (0.058 –0.082 mm long 0.047 –0.064 mm wide); smaller crosses, all of them with tubercular ornamentation ( Fig. 5A View FIGURE 5 ).

Pharyngeal sclerites are small warty plates (0.07–0.13 mm long, 0.010 –0.032 mm wide) ( Fig. 5B View FIGURE 5 ).

Neck zone sclerites are short, blunt rods, crosses with tubercular ornamentation; 0.16– 0.07 mm in length, 0.05– 0.01 mm wide; some crosses ( Fig. 6A View FIGURE 6 ).

I ntrusion sclerites are irregular-shaped, branched rods with tubercular ornamentation (0.14–0.52 mm long, 0.03–0.11 mm wide) ( Fig. 6B View FIGURE 6 ).

Calyx wall sclerites are irregular-shaped; crosses with dense tubercular ornamentation (0.45– 0.15 mm long 0.37– 0.06 mm wide); frequently with cross-like prominences ( Fig.7A View FIGURE 7 ).

Stolon sclerites are smooth to slightly warty plate,crosses; irregular-shaped with slightly tubercular ornamentation (0.40– 0.19 mm long 0.42– 0.02 mm wide); less cross-shaped forms (0.12– 0.25 mm long) ( Fig. 7B View FIGURE 7 ).

Remarks. The sclerome found in Telestula ridgensis sp. nov. is unique among the north-eastern Atlantic congeners having longitudinal rows of small warty rods and cross-like forms that extend from the distal end of the calyx towards the base of the tentacles. The sclerites of the new species from the neck zone, intrusion tissue, calyx wall, and ribbon-like stolon are notably different among the genus Telestula with an evident abundance of warty, irregular, and cylinder-like forms of small flattened ovals. Telestula ridgensis sp. nov. is morphologically closely related to Telestula septentrionalis , T. cf. batoni , and T. cf. spiculicula . According to Tixier-Durivault (1964) species, T. tubaria has eight chevrons of small sclerites in the neck region and eight longitudinal ridges of sclerites in a calyx wall. However, T. versluysi has densely tuberculate rounded spindles from the calyx wall and irregular spindles from the stolon ( Weinberg 1990). T. mosaica has some arrowhead-like sclerites. The sclerites of T. kuekenthali have loose polyps, plump, coarsely tuberculate spindles from the calyx wall, irregular spindles, and cross-shaped sclerites from the top of the polyp ( Weinberg 1990). Telestula stocki has plates on top of tentacles, sparse long spindles, warty spindles with complex tubercles, rods from stolon, and plump ( Weinberg 1990).