Synoptic Keys to the Genera of Ophiuroidea
Family Ophiothricidae Ljungman, 1866
Family Ophiothricidae Ljungman, 1866
Radial shields low, without a raised crest.
Disc covered above and below by naked skin through which only the distal ends of the radial shields project; no tentacle scales or, at most, scales present only on basal arm-joints. . . . Ophiogymna Ljungman, 1866.
Syn.: Ophiocampsis Duncan, 1887 (see Koehler 1922a, p. 284).
*elegans Ljung., 1866. Indonesia. Littoral.
Disc not covered by naked skin.page 24
Upper surface of disc bearing granules.
Lower surface of disc covered by skin.
Dorsal surface of arms bearing granules, tubercles or coarse irregular grains, which more or less obscure the plates; dorsal arm-plates reduced in size. . . . Ophiothela Verrill, 1867.
Syn.: Ophioteresis Bell, 1892 (juvenile stage).
*mirabilis Verrill, 1867. Panama. Littoral.
Entire dorsal surface of disc and arms densely coated with uniform granules which completely obscure all plates; tentacles issue from side of arms. . . . Ophiopsammium Lyman, 1874.
*semperi Lyman, 1874. Philippine Is. Littoral.
Lower surface of disc covered by fine scales. . . . Ophiocnemis Mueller & Troschel, 1842.
*Ophiura marmorata Lmk., 1816. Indian Ocean. Littoral.
Upper and lower surfaces of disc covered by plates.
Disc covered by primary plates and radial shields; two arm-spines. . . . Ophiophthirius Doederlein, 1898.
*actinometrae Doed., 1898. Torres Strait. Littoral.
The type (and only known) species was epizoic on a comatulid, and may be a juvenile stage of some other genus.
Disc covered by numerous other plates, besides the primaries; four or more arm-spines.
Radial shields large and conspicuous.
Disc plates bear spines or thorns.
Arm-spines of the proximal arm-joints united by a membranous web into vertical fin-like fans. . . . Ophiopteron Ludwig, 1888.
*elegans Ludwig, 1888. Amboina. Littoral.
Mortensen (1932) has shown that some spp. of Ophiothrix pass through an "Ophiopteron" stage.
Arm-spines of all arm-joints free, not united by webs. . . . Macrophiothrix H. L. Clark, 1938.
Syn.: Placophiothrix H. L. Clark, 1938.
*Ophiura longipeda Lmk., 1816. Indo-Pacific. Littoral.
Disc plates without spines or thorns.
Dorsal arm-plates short and wide; arm-spines smooth and opaque. . . . Ophiomaza Lyman, 1871.
Syn.: Lütkenia Brock, 1888.
*cacaotica Lyman, 1871. Indo-West-Pacific. Littoral.
Species of this genus may occur as epizoic forms on various comatulids.
Dorsal arm-plates not short and wide; arm-spines thorny. . . . Ophiotrichoides Ludwig, 1882.
*lymani Ludwig, 1882. Tropical W. Atlantic. Littoral.
The genus is strongly represented in the Indo-Pacific, and at least one species has an "Ophiopteron" stage; see H. L. Clark (1946, p. 230).
Radial shields small or partly concealed by spinules.
Dorsal arm-plates bearing minute spinelets. . . . Amphiophiothrix H. L. Clark, 1946.
*Ophiothrix demessa Lyman, 1861. Tropical Indo-Pacific. Littoral.
Dorsal arm-plates smooth.
Spines or thorns on disc plates; tentacle-scales present. . . . Ophiothrix Mueller & Troschel, 1840.page 25
Syn.: Ophionyx M. & T., 1840.
*Asterias pentaphylla Pennant, 1777. Britain. Littoral.
Disc plates with no spines or thorns.
Arm-spines not longer than width of arm; radial shields contiguous along their whole length; androphorous, epizoic on Diadema and Toxopneustes; distal arm-spines hooked. . . . Ophiosphaera Brock, 1888.
*insignis Brock, 1888. Amboina. Littoral.
Arm-spines long and slender, up to four times as long as width of arm; radial shields scarcely contiguous. . . . Lissophiothrix H. L. Clark, 1938.
*delicata H. L. Clark, 1938. Tropical Australia. Littoral.
Radial shields each carry a raised vertical crest. Disc naked above and below, or with only a few small scattered scales imbedded in skin.
Some proximal dorsal arm-plates carry a high median keel; beyond disc ventral arm-plates become rounded and widely separated. . . . Ophiolophus Marktanner-Turneretscher, 1887.
*novarae M-T, 1887. Nicobar Is. Littoral.
Dorsal arm-plates without keels.
Disc and arms minutely granulated. . . . Gymnolophus Brock, 1888.
*Ophiothela holdsworthii E. A. Smith, 1878. Ceylon.
Disc and arms naked. . . . Ophioaethiops Brock, 1888.
Syn.: Ophiohelix Koehler, 1895.
*unicolor Brock, 1888. Amboina. Littoral.