Explanation of main chaetae terminology (all chaetae of postacicular rows) A, B geniculate chaeta of Nephtys cirrosa C spinose chaeta of Nephtys ciliata, frontal view D serrate chaeta of Nephtys hombergii, lateral view E lyrate chaeta of Inermonephtys foretmontardoi (after Ravara et al. 2010).