, Volume 216, Issue 1, pp 45–49 | Cite as

Rhopalium development in Aurelia aurita ephyrae

  • Dorothy B. Spangenberg
Proceedings I. Cellular biology


Rhopalia of developing ephyrae were examined using the SEM and TEM at 24 h intervals following strobilation induction. Kinocilia are shorter in the ephyra stage than in polyps. A few ephyra-type kinocilia are found in rhopalia as early as 24 h after induction, before a distinct rhopalium is seen. By 72 h, the shorter kinocilia predominate and are almost as numerous as in ephyrae (120 h). Many of the kinocilia are associated with mechanoreceptor cells (MR) found in the rhopalia. These MR cells are compared to those reported for medusae. Although newly released ephyrae lack a touch plate, the MR cells in their rhopalia along with the statocyst and neuromuscular system apparently enable these organisms to detect and respond to gravity.

Key words

jellyfish ephyra rhopalium kinocilia mechanoreceptor ultrastructure 


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Copyright information

© Kluwer Academic Publishers 1991

Authors and Affiliations

  • Dorothy B. Spangenberg
    • 1
  1. 1.Department of PathologyEastern Virginia Medical SchoolNorfolkUSA

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