First record of brittle star from the Northern Indian Ocean

Ophioplocus declinans

Phylum: Echinodermata

Class: Ophiuroidea Gray, 1840

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

Family: Hemieuryalidae Verrill, 1899

Ophioplocus declinans (Koehler, 1904)

Collection: Andaman & Nicobar Islands — Off Kamorta Island, 8° 21.91’ N, 93° 34.37’ E, 71 m (FORVSS388, St.12), 13.08.2019, dredge, 1 specimen.

Voucher No.: CMLRE IO/SS/ECD/00244.

Description: Disc pentagonal, arms 4-5 times disc diameter. Disc scales large, polygonal or rounded, arranged irregularly; scales, oral shield, adoral shield and oral plate, as well as dorsal, ventral and lateral arm plates strongly beaded. Radial shields small, triangular to oval, separated by a row of 2–3 transversely wide disc scales; a pair of rounded disc scales distal to the radial shields, between which the first dorsal arm plate is wedged. Four conical, pointed papillae on each side of the jaw. Arm spines numbering four; conical, short, less than half the segment in length; subequal, the ventral-most slightly longer and stouter. Preserved specimen grey overall with darker and lighter patches on the disc dorsally.

Biological association: None.

Remarks: The single specimen collected from the Nicobar Islands is a juvenile, indicated  by the smaller size and arrangement as well as relative development of skeletal elements.

Distribution: India: Andaman & Nicobar Islands, Indonesia, north-western Australia, Philippines, Papua New Guinea; 30–400 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.

Add a Comment

Your email address will not be published. Required fields are marked *