Light micrographs showing the morphologies of living spionid larvae of the genus Polydora A, B Polydora brevipalpa, dorsal view of 15‐chaetiger (A) and 17‐chaetiger larvae (B) C, D Polydora cornuta, dorsolateral view of 11‐chaetiger larva (C) and ventral view of 17‐chaetiger larva (D) E Polydora cf. glycymerica, dorsal view of 25‐chaetiger larva F Polydora hoplura, dorsal view of 15‐chaetiger larva G–I Polydora onagawaensis, dorsal view of 10‐chaetiger (G) and 18‐chaetiger larvae (H), and lateral view of 16‐chaetiger larva (I) J Polydora cf. spongicola, dorsal view of 17‐chaetiger larva K, L Polydora sp. 1, dorsal view of 7‐chaetiger (K) and 16‐chaetiger larvae (L) M Polydora sp. 2, dorsal view of 23‐chaetiger larva N–P Polydora sp. 3, dorsal view of 13‐chaetiger (N) and dorsal (O) and lateral view (P) of 18‐chaetiger larvae. Scale bars: 300 μm.