, Volume 115, Issue 4, pp 221–227 | Cite as

Ocelli in a Cnidaria polyp: the ultrastructure of the pigment spots in Stylocoronella riedli (Scyphozoa, Stauromedusae)

  • Michael J. F. Blumer
  • Luitfried v. Salvini-Plawen
  • Reinhard Kikinger
  • Thomas Büchinger
Original Article


Within the Cnidaria, the occurrence of ocelli at the polyp stage is only known in the species of Stylocoronella (Scyphozoa, Stauromedusae). The light-sensitive organs of S. riedli are ultrastructurally investigated. In this interstitial-living species, each of the up to 24 ocelli is composed of between seven and nine monociliary sensory cells and between one and four pigment cells. A striking feature of the photoreceptive cilia is their peculiar axonemal pattern. This is expressed (a) by the presence of a third central microtubule at a certain point and (b) by the balloon-like swelling of the distal portion of the cilium, with clearly scattered microtubules in this area. Although the polyps of S. riedli show no distinct reaction to light stimuli, the ultrastructural results corroborate the hypothesis that these organs are light-sensitive organs. The possible function of the pigment granules is discussed.


Developmental Biology Striking Feature Distal Portion Sensory Cell Light Stimulus 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.



basal body






crescent-shaped vesicle


clear vesicle


dense-core vesicles






multivesicular body






piment cell


pigment granule


sensory cell


striated rootlet




Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. Berrill M (1962) The biology of three New England Stauromedusae, with a description of new species. Can J Zool 40:1249–1262Google Scholar
  2. Besteiro C, Urgorri V (1988) Cnidarios mesopsamicos novos para o litoral iberico recolhidos na galiza. Cienc Biol Ecol Sist (Portugal) 8(1/2):43–45Google Scholar
  3. Blumer M (1994) The ultrastructure of the eyes in the veliger-larvae of Aporrhais sp. and Bittium reticulatum (Mollusca, Caenogastropoda). Zoomorphology 114:149–159Google Scholar
  4. Bouillon J, Nielsen M (1974) Etude de quelques organes sensoriels de Cnidaires. Arch Biol 85(3):307–328Google Scholar
  5. Chia F, Amerongen HM, Peteya DJ (1984) Ultrastructure of the neuromuscular system of the polyp of Aurelia aurita L. 1758 (Cnidaria, Scyphozoa). J Morphol 180:69–79Google Scholar
  6. Clark J (1878) Lucernariae and their allies. Smithson Contrib Knowl 23:1–130Google Scholar
  7. Eakin RM (1982) Continuity and diversity in photoreceptors. In: Westfall J (ed) Visual cells in evolution. Raven Press, New York, pp 91–106Google Scholar
  8. Eakin RM, Hermans CO (1988) Eyes. Microfauna Marina 4:135–156Google Scholar
  9. Eakin RM, Westfall JA (1962) Fine structure of photoreceptors in hydromedusae, Polyorchis penicillatus Proc Nat Acad Sci USA 48:826–833Google Scholar
  10. Fahrenbach WH (1963) The fine structure of a nauplius eye. Z Zellforsch 62:182–197Google Scholar
  11. Golz R, Thurm U (1993) Ultrastructural evidence for the occurrence of three types of mechanosensitive cells in the tentacles of the cubozoan polyp (Carybdea marsupialis). Protoplasma 173:13–22Google Scholar
  12. Howard DR, Martin GG (1984) Fine structure of the eyes of the interstitial gastropod Fartulum orcutti (Gastropoda, Prosobranchia). Zoomorphology 104:197–203Google Scholar
  13. Kikinger R, Salvini-Plawen L (1995) Development from polyp to stauromedusa in Stylocoronella (Cnidaria: Scyphozoa). J Mar Biol Assoc UK (in press)Google Scholar
  14. Salvini-Plawen L (1966) Zur Kenntnis der Cnidaria des nordadriatischen Mesopsammon. Veröffentlichungen des Instituts für Meeresforschung in Bremerhaven, Sonderband II. Franz Leuwer, Bremen, pp 165–186Google Scholar
  15. Salvini-Plawen L (1987) Mesopsammic Cnidaria from Plymouth (with systematic notes). J Mar Biol Assoc UK 67:623–637Google Scholar
  16. Salvini-Plawen L, Mayr E (1977) On the evolution of photoreceptors and eyes. Evol Biol 10:207–263Google Scholar
  17. Singla CL (1974) Ocelli of Hydromedusae. Cell Tissue Res 149:413–429Google Scholar
  18. Singla CL, Weber C (1982) Fine structure of the ocelli of Polyorchis penicillatus (Hydrozoa, Anthomedusae) and their connection with the nerve ring. Zoomorphology 99:117–129Google Scholar
  19. Weber CH (1981) Structure, histochemistry, ontogenetic development, and regeneration of the ocellus of Cladonema radiatum Dujardin (Cnidaria, Hydrozoa, Anthomedusae). J Morphol 167:313–331Google Scholar
  20. Yamamoto M, Yoshida M (1980) Fine structure of ocelli of an anthomedusan, Nemopsis dofleini, with special reference to synaptic organization. Zoomorphology 96:169–181Google Scholar
  21. Yamasu T, Yoshida M (1973) Electron microscopy on the photoreceptors of an Anthomedusa and a Scyphomedusa. Seto Mar Biol Lab 20:757–778Google Scholar
  22. Yamasu T, Yoshida M (1976) Fine structure of complex ocelli of a cubomedusan, Tamoya bursaria Haeckel. Cell Tissue Res 170:325–339Google Scholar

Copyright information

© Springer-Verlag 1995

Authors and Affiliations

  • Michael J. F. Blumer
    • 1
  • Luitfried v. Salvini-Plawen
    • 1
  • Reinhard Kikinger
    • 1
  • Thomas Büchinger
    • 1
  1. 1.Abteilung für Systematische ZoologieInstitut für Zoologie der Universität WienWienOsterreich

Personalised recommendations