Arrangement of superficial neuromasts on the threespine stickleback. (A) View of a representative threespine stickleback head stained with DASPEI to highlight superficial neuromasts. Scale bar=5 mm. (B) Scanning electron micrograph of a preopercular superficial neuromast on a Little Campbell marine threespine stickleback. Scale bar=5 μm. (C) Schematic representation of neuromast arrangement. Abbreviations for line names: infraorbital (IO), oral (OR), mandibular (MD), preopercular (PO), otic (OT), supratemporal (ST), main trunk line anterior (Ma), main trunk line posterior (Mp), caudal fin (CF), ethmoid (ET), supraorbital (SO) and anterior pit (AP).