, beyond or beside + podia
, feet), singular parapodium
, are paired un-jointed lateral
outgrowths. They are characteristic of Polychaeta
, but they also occur in opisthobranch molluscs
Parapodia are either uniramous or biramous. In the latter case, the dorsal lobes or branches are called notopodia and the ventral branches neuropodia.
Both neuropodia and notopodia can bear cirri (called respectively neurocirri and notocirri) and setae (called respectively neurosetae and notosetae). The cirri between the two branches are called interramal cirri.
The fleshy protrusions on the sides of some snails are also called parapodia (especially characteristic of sea butterflies).