First record of brittle star from the Northern Indian Ocean

Ophialcaea tuberculosa

Phylum: Echinodermata

Class: Ophiuroidea Gray, 1840

Order: Ophiacanthida O’Hara, Hugall, Thuy, Stöhr & Martynov, 2017

Family: Ophiacanthidae Ljungman, 1867

Ophialcaea tuberculosa (Lyman, 1878)

Collection: Andaman & Nicobar Islands — Off Great Nicobar Island, 7° 42.68’ N, 93° 19.64’ E, 395 m (FORVSS292, St. 90), 13.12.2011, demersal trawl; 13° 19.19’ N, 93° 15.72’ E, 635 m (FORVSS367II, St. 08), 26.11.2017, demersal trawl.

Voucher No.: CMLRE IO/SS/ECD/00253, 00254, 00255.

Description: Disc excavate interradially, arms 4–5 times disc diameter. Disc scaling obscured by skin, which bears spaced, low conical tubercles on the dorsal and ventral surface; radial shields separated throughout their length; visible as narrow, raised bars underneath the tuberculated skin. Oral shields twice as wide as long; with an acute proximal angle, concave lateral margins and a wide, straight distal margin. Three papillae along each side of the jaw. Arm spines stout and blunt, slightly longer than the corresponding segment in length; numbering 4–5 basally, of which the dorsal-most is slightly stouter and longer. Tentacle scale lanceolate, approximating the length of the ventral arm plate.

Biological association: This species was collected with the cidarid urchin Histocidaris denticulata Koehler, 1927 on both occasions, and in one case (FORVSS292, St. 90), the specimen was entangled with the urchin’s spines; it is possibly associated with H. denticulata as an epibiont.

Remarks: None.

Distribution: India: Andaman & Nicobar Islands, Indonesia, western Australia, Philippines, Papua New Guinea; 640–970 m.

Distribution map:


Identified by: Usha V. Parameswaran

Publication: Parameswaran U. V., Gopal A., Abdul Jaleel K. U., Saravanane N. 2021. Nine new records of brittle stars (Echinodermata: Ophiuroidea) from Indian waters. Marine Biology Research, 17(5-6): 434-453. DOI: 10.1080/17451000.2021.1967995.

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