Figure 15. Ophiopus arcticus postlarval development. A, B, 0.7 in Who's who among baby brittle stars (Echinodermata: Ophiuroidea): postmetamorphic development of some North Atlantic forms

Figure 15. Ophiopus arcticus postlarval development. A, B, 0.7 mm dd postlarva; A, dorsal, note the projecting madreporite; B, ventral, note the wide flat tooth (T); C, D, 0.9 mm dd postlarva; C, dorsal; D, ventral (a stray arm spine lies on a jaw); E, F, 1.3 mm dd postlarva; E, dorsal, note k-plate (k) and first inter-radials (IR1); F, ventral, note the second mouth papillae (MP2) on the dental plate; G, H, 1.4 mm dd postlarvae; G, dorsal, note the secondary inter-radial plates (SIR); H, ventral. Abbreviations: as in Figs 1–3, 5. Scale bars in millimetres.