A Preliminary experiment of rejuvenation in Turritopsis sp. (Hydrozoa, Anthomedusae) by freshwater immersion.

Abstract

Immature medusae of Turritopsis sp. obtained from cultured polyps originated from a medusa collected from Shirahama, Wakayama Prefecture, Japan at the Seto Marine Biological Laboratory, Kyoto University were experimentally treated 50 % seawater (16 psu) or 100% freshwater (DW) immersion for the following minutes: 5, 10, 120. Only one medusa can be rejuvenated unexpectedly due to unknown reason, keeping it in the 50% seawater for 120 mins. We infer that instant immersion caused sudden drop of salinity is unfavourable and severe even in 5 minutes immersion, resulting very low rate of rejuvenation.