Ophioleucidae Matsumoto, 1915

Goharimanesh, Mona, Stöhr, Sabine, Mirshamsi, Omid, Ghassemzadeh, Fereshteh & Adriaens, Dominique, 2021, Interactive identification key to all brittle star families (Echinodermata; Ophiuroidea) leads to revised morphological descriptions, European Journal of Taxonomy 766 (1), pp. 1-63 : 38-39

Family Ophioleucidae Matsumoto, 1915

Type genus

Ophioleuce Koehler, 1904 .

Other genera

Ophiopallas Koehler, 1904 ; Ophiopyren Lyman, 1878 ; Ophiostriatus Madsen, 1983 .

Description

ARM.Arm shape unbranched; length more than4×disc diameter;covering without granules/spines/tubercles. Arm combs absent. Dorsal arm plate present. Accessory dorsal arm plate absent. Ventral arm plate present. Accessory ventral arm plate absent. Girdle of tiny hooks on the arms absent. Spines all similar or not all similar in shape ( Ophiopallas ). The atypical spines are hook-shaped. Arm spine cross section round. The ratio of thickness of distal ⅓ of arm spine to maximum thickness (in a given cross-sectional plane) 0.6–0.9. Arm spines pointed; mainly lateral; predominantly parallel to arm axis (adpressed). Longest arm spines between half and one segment long. Tentacle scales present; pores visible along most of the arm; nearly as long as wide; shorter than the spine nearby; cross section round. Position of lateral arm plate (LAP) arched (wrapped around the arm). Dorsal and/or ventral edge(s) of LAPs without constriction. Ventral position of LAP projecting ventro-proximalwards. Ventro-distal tip of LAP projecting ventralwards. Arm spine articulation with dorsal and ventral lobes; without sigmoidal fold; arranged over entire distal LAP edge; larger in middle of arm. Distance between spine articulations dorsalwards increasing, or not applicable (two spine articulations) ( Ophioleuce seminudum Koehler, 1904 ). Nerve and muscle openings separated by small ridge if at all. Nerve opening smaller than muscle opening.

DORSAL DISC. Disc circular; flat (about same level as arms). Integument obscuring plates. Dorsal disc with granules; with concealed primary plates; with scales; without spines. Dorsal disc scale/plate without tubercles. Radial shield present; with granules; length less than one third of the disc radius; scalene (oblique) triangular.

VENTRAL DISC. Gonads restricted to the disc. Ventral interradii with granules. Scales on ventral interradii absent. Ventral teeth several (tooth papillae). Infradental papillae on oral plate present. Buccal scales on OP absent. Accessory oral papillae on OP absent. Lateral oral papillae on OP absent. Adoral shield spine absent. Lyman’s ossicle present. Oral shield covering less than one third of interradius; much longer than wide. Madreporite multiple; with numerous pores. Adoral shield meeting in front of the oral shield. Abradial genital plate not twisted. Number of genital slits one per bursa. Genital slit longer than half the length of an interradius. Genital papillae present (O phiopallas) or absent. Dental plate ventral half widest; entire (single plate). Dental sockets slit-shaped; less than 50% of the width. At least one socket on DP as depression or perforation without septum. Teeth spine-shaped. Teeth on DP arranged as single row.

VERTEBRAE. Vertebrae hourglass-shaped (streptospondylous); beyond segment 5 with short keel; without oral bridge.