The Echinoid Directory

Colobocentrotus Brandt, 1835, p. 266

[=Colobocentrus Gray, 1840, (objective). ]

Diagnostic Features
  • Test ovate in outline with large, ovate peristomial opening. Test elongate along the axis passing through ocular plate II and genital plate 4.
  • Apical disc dicyclic.
  • Pore-pairs in arcs of 8-12 on each plate; expanding into broad phyllodes adorally.
  • Aborally pore-pairs forming a double, rather irregular series.
  • Ambulacral tubercles very massive; with two secondary perradial tubercles almost as large as the primary above the ambitus.
  • Aboral interambulacral plates covered in numerous large tubercles without order; secondaries as large as the primaries. At ambitus primaries become prominent and dominate.
  • Aboral spines short and peg-like, forming a distinctive pavement. There is a downward-facing fringe of small paddle-like spines around the margin.
Distribution
Recent, Bonin Islands.
Name gender masculine
Type
Colobocentrotus mertensenii Brandt, 1835, p. 266 by monotypy.
Species Included
  • C. mertensenii Brandt, 1835; Recent, Bonin Islands.
Classification and/or Status

Camarodonta; Echinoida; Echinometridae.

Monotypic.

Remarks

Heterocentrotus differs from Colobocentrotus in having massive pencil-like aboral spines and single large tubercles on aboral plates. Podophora is very similar but in Podophora aboral spines are flat-topped and fit together to form a tesselated outer protective surface. In Colobocentrotus the aboral spines are short and button like and not tesselated. In aspects of test morphology Colobocentrotus has multiple aboral ambulacral tubercles while Podophora has single tubercles to each plate. Colobocentrotus also has more numerous aboral interambulacral tubercles that are not arranged into regular rows whereas in Podophora the tubercles are fewer and in obvious rows. Mortensen (1943) maintained the two at subgenus level.

Members live on rocky shores exposed to extreme wave-surge. Their enormous adoral phyllodes are an adaption for life in this extreme habitat.

Brandt, J. F. von 1835 Prodr. Descr. Anim. Rec. Actes Acad. Imp. Sci. Petersburg [1834], p. 266