The reproductive biology of Parazoanthus parasiticus (Hexacorallia: Zoanthidea) in Bermuda

  • J. S. Ryland
  • DÖrte Westphalen
Conference paper
Part of the Developments in Hydrobiology book series (DIHY, volume 178)

The zooxanthellate macrocnemic zoanthid Parazoanthus parasiticus lives at densities of 3–10 cm–2 in the chimney sponge Callyspongia vaginalis in Bermuda. It is gonochoric and oviparous. Small oocytes appear in the mesenteries in February–March, grow slowly at first, then increase volume rapidly as seawater temperature passes 27 °C in July. In 1993, oocytes were found to have been shed over 2–3 days around the full moon on 1 September, with inferred small spawnings over the preceding and following full moons. Reproduction had finished by November. In 1999, spawning of azooxanthellate eggs ~250 μm diameter took place on 28 August, two nights after full moon. Spawnings therefore precede those known for four oviparous scleractinians and one gorgonian in Bermudian waters by about a week. The eggs are not shed in bundles and lack zooxanthellae. The unknown embryonic development and larval type in macrocnemic zoanthids is discussed and remains to be resolved by further study with P. parasiticus.

Key words: Macrocnemina, zoanthina, gonochorism, spawning, Castle Harbour, zooxanthellae


Great Barrier Reef Patch Reef Scleractinian Coral Full Moon Moon Phase 
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.


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Copyright information

© Kluwer Academic Publishers 2004

Authors and Affiliations

  • J. S. Ryland
    • 1
  • DÖrte Westphalen
    • 2
  1. 1.School of Biological SciencesUniversity of Wales SwanseaUK
  2. 2.Bermuda Biological Station for ResearchBermuda

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