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Updated: Jun 12, 2026

Inducing Complete Polyp Regeneration from the Aboral Physa of the Starlet Sea Anemone Nematostella vectensis
Published on: January 14, 2017
Three consecutive generations of nephridia occur during development of Platynereis dumerilii (Annelida, Polychaeta)
Christian Hasse1, Nicole Rebscher, Wencke Reiher
1Morphology and Evolution of Animals, Philipps-Universität Marburg, Karl-von-Frisch-Strasse 8, Marburg, Germany.
Abstract:
Molecular data for nephridial development in polychaetes are not available yet. The scope of our work was to establish a reference system for future investigations using two markers for nephridial development: beta-tubulin as marker for cilia and alkaline phosphatase (AP) activity for secretory epithelia. The markers identified, unexpectedly, three consecutively forming generations of nephridia: (1) a transitory unciliated, but AP-positive head kidney, (2) a transitory larval nephridium, which undergoes a morphological transition from a protonephridium to a funnelled nephridium concomitant with the development of the coelomic cavity and finally, (3) the serially arranged metanephridia. The spatial arrangement of larval and definitive nephridia, revealed an up to now unknown developmental boundary between the synchronously forming larval and the serially proliferating definitive segments. Development of three consecutive sets of nephridia with different morphology and biochemical properties was unexpected and reveals an interesting multistep process in the development of excretory structures in Platynereis.
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