There are no branchiae on the parapodial lobes and the anterior setae have long, curved bidentate blades.
Ventral cirri are attached at the base of the parapodial lobe and the ventral cirri at the base of setiger 1 are broad and laminar.
Innervation of parapodial muscles by pedal ganglion motorneurons.
Organization of pedal motorneurons and parapodial motor fields.
Newly formed terminal setigers develop chaetae and parapodial
lobes typical of the tail region (Fig.
Appearing at this stage are visible palp and anterior parapodial rudiments.
The parapodial rudiments of setigers A1-A9 emerge laterally, correlated with a dorsoventral flattening of region A.
The genus Chaetopterus has several species that show variation in overall adult size, tube morphology, and details of parapodial and setal form.
A metamorphic inducer was present in methanol extracts of several adult tissues, with most activity occurring in extracts of the posterior mucous gland of the female reproductive tract (61% intracapsular metamorphosis occurred), digestive gland (49%), and parapodial
lobes (56%; Fig.