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schematic cross-section through nereis pelagica , bristles and muscles of the parapodium

As parapodium ( Latinization of ancient Greek παραπόδιος parapódios , at the feet lying ') is called in biology a rigid leg-like extension which, however, as opposed to a "real" mobile leg can not be actively moved.

Parapodia can be found, for example, in annelids (Annelida). Parapodies serve the polychaetes as lateral rudders, the construction of which can be modified depending on the lifestyle and family affiliation. The basic type consists of a dorsal back paddle (Notopodium) and a ventral abdominal paddle (Koilopodium = Neuropodium). The branches often carry bundles of bristles made of chitin , some of which do not protrude from their follicles (aciculae) and serve as supports. Muscles insert at the end (basal), thereby achieving mobility. Dorsally and ventrally, the parapodium has a probe-like appendix, the cirrus. In addition, gill appendages appear dorsally. However, other parts (notopodium, cirrus etc.) can also serve as respiratory organs.

Individual evidence

  1. ^ Wilhelm Gemoll : Greek-German school and hand dictionary . G. Freytag Verlag / Hölder-Pichler-Tempsky, Munich / Vienna 1965.