Sphaerodoridium balticum, from Norwegian Sea (ZMBN 129499 , SPH281), scanning electron micrographs. A Complete specimen, dorsal view B head, lateral view C palps with spurs and lateral antennae (behind), detail D epithelial tubercles over dorsum E parapodium, chaetiger 1 F parapodium, chaetiger 4 G parapodia, chaetigers 7 and 8, with a sexual structure in between (male) H genital pores between parapodia chaetiger 7 and 8 (female) I male genital organ, detail J chaetae, chaetiger 1 K, L chaetae, mid-body parapodia.