Light micrographs showing morphologies of living spionid larvae of Aonides, Laonice, Rhynchospio, Scolelepis, and Spiophanes A–C Aonides cf. oxycephala, dorsal view of early planktonic (A), 8‐chaetiger (B), and 18‐chaetiger larvae (C) D Laonice sp. 1, dorsal view of early planktonic larva E Laonice sp. 2, dorsal view of 12‐chaetiger larva F Poecilochaetus sp., dorsal view of 17‐chaetiger larva G, H Rhynchospio aff. asiatica, dorsal view of 6‐chaetiger (G) and 12‐chaetiger larvae (H) I Scolelepis cf. kudenovi, dorsal view of 7‐chaetiger larva J, K Scolelepis sp. 1, dorsal view of 17‐chaetiger (J) and 19‐chaetiger larvae (K) L Scolelepis sp. 2, dorsal view of 20‐chaetiger larva M, N Spiophanes uschakowi, dorsal (M) and lateral view (N) of 18‐chaetiger larvae O, P Spiophanes aff. uschakowi, dorsal view of 16‐chaetiger larva (O) and 27‐chaetiger juvenile (P). Scale bars: 300 μm.