Coral Reefs

, Volume 28, Issue 3, pp 677–680 | Cite as

Coral spawn timing is a direct response to solar light cycles and is not an entrained circadian response

  • A. K. Brady
  • J. D. Hilton
  • P. D. VizeEmail author


Broadcast spawning corals release gametes into the oceans with extraordinarily accurate timing. While the date of spawning is set by the lunar cycle, the hour/minute of spawning is set by the solar cycle. In this report, we describe experiments that test whether the time of spawning is regulated by an entrained biological clock or whether it is directly controlled by the solar cycle. Montastraea franksi samples were collected on the morning of the predicted spawning. Fragments from colonies were kept under three different lighting conditions and spawning monitored. The three conditions were sunset times of 0, 1 or 2 h earlier than normal. Fragments from the same colony spawned differently under these three conditions, with an early sunset causing a corresponding early shift in spawning. These results indicate that spawn timing is not controlled by a circadian rhythm and that it is directly controlled by local solar light cycle.


Broadcast spawning Circadian rhythm Biological clock Mass spawning 



This research was supported by NOAA and the Flower Garden Banks National Marine Sanctuary. Additional support was provided by Galatee Films by providing ship time and we would like to especially thank Antoine de Cozette for help in coordinating field work. Field work was aided by Sarah Davies, Kurt Carlson, Jay Reichman, Mike Nickell, Emma Hickerson and the crew of the M.V. Fling.


  1. Anctil M, Hayward DC, Miller DJ, Ball EE (2007) Sequence and expression of four coral G protein-coupled receptors distinct from all classifiable members of the rhodopsin family. Gene 392:14–21CrossRefPubMedGoogle Scholar
  2. Babcock RC (1984) Reproduction and distribution of two species of Goniastrea (Scleractinia) from the Great Barrier Reef province. Coral Reefs 2:187–195Google Scholar
  3. Babcock RC, Bull GD, Harrison PL, Heyward AJ, Oliver JK, Wallace CC, Willis BL (1986) Synchronous spawnings of 105 scleractinian coral species on the Great Barrier Reef. Mar Biol 90:379–394CrossRefGoogle Scholar
  4. Dunlap JC, Loros JL, DeCoursey PJ (2004) Chronobiology: biological timekeeping. Sinauer Associates, Inc., Sunderland, MAGoogle Scholar
  5. Gorbunov MY, Falkowski PG (2002) Photoreceptors in the cnidarian hosts allow symbiotic corals to sense blue moonlight. Limnol and Oceanogr 47:309–315Google Scholar
  6. Hagman DK, Gittings SR, Deslarzes KJ (1998) Timing, species participation, and environmental factors influencing annual mass spawning at the Flower Garden Banks (northwest Gulf of Mexico). Gulf Mex Sci 16:170–179Google Scholar
  7. Harrison PL, Babcock RC, Bull GD, Oliver JK, Wallace CC, Willis BL (1984) Mass spawning in tropical reef corals. Science 223:1186–1189CrossRefPubMedGoogle Scholar
  8. Hunter CL (1988) Environmental cues controlling spawning in two Hawaiian corals, Montipora verruscosa and M. Dilatata. Proc 6th Int Coral Reef Symp 2: 727-732Google Scholar
  9. Jokiel PL, Ito RY, Liu PM (1985) Night irradiance and synchronization of lunar release of planula larvae in the reef coral Pocillopora damicornis. Mar Biol 88:167–174CrossRefGoogle Scholar
  10. Knowlton N, Mate JL, Guzman HM, Rowan R, Jara J (1997) Direct evidence for reproductive isolation among the three species of the Montastraea annularis complex in Central America (Panama and Honduras). Mar Biol 127:705–711CrossRefGoogle Scholar
  11. Levitan DR, Fukami H, Jara J, Kline D, McGovern TM, McGhee KE, Swanson CA, Knowlton N (2004) Mechanisms of reproductive isolation among sympatric broadcast spawning corals of the Montastraea annularis species complex. Evolution 58:308–323PubMedGoogle Scholar
  12. Levy O, Appelbaum L, Leggat W, Gothlif Y, Hayward DC, Miller DJ, Hoegh-Guldberg O (2007) Light-responsive cryptochromes from a simple multicellular animal, the coral Acropora millepora. Science 318:467–470CrossRefPubMedGoogle Scholar
  13. Mendes JM, Woodley JD (2002) Timing of reproduction in Montastraea annularis: relationship to environmental variables. Mar Ecol Prog Ser 227:241–251CrossRefGoogle Scholar
  14. Penland L, Kloulechad J, Idip D, van Woesik R (2004) Coral spawning in the western Pacific Ocean is related to solar radiation: evidence of multiple spawning events in Palau. Coral Reefs 23:133–140CrossRefGoogle Scholar
  15. Rayer B, Naynert M, Stieve H (1990) Phototransduction: Different mechanisms in vertebrates and invertebrates. J Photochem Photobiol B 7:107–148CrossRefPubMedGoogle Scholar
  16. Shelton GA (1975) Colonial conduction systems in the anthozoa: Octocorallia. J Exp Biol 62:571–578PubMedGoogle Scholar
  17. Sweeny BM (1976) Circadian rhythms in corals, particularly Fungiidae. Biol Bull 151:236–246CrossRefGoogle Scholar
  18. van Veghel ML (1993) Multiple species spawning on Curacao. Bull Mar Sci 52:1017–1021Google Scholar
  19. van Woesik R, Lacharmoise F, Koksal S (2006) Annual cycles of solar insolation predict spawning times of Caribbean corals. Ecol Lett 9:390–398CrossRefPubMedGoogle Scholar
  20. Vize PD (2009) Transcriptome analysis of the circadian regulatory network in the coral, Acropora millepora. Biol Bull 216:131–137 PubMedCrossRefGoogle Scholar
  21. Vize PD, Embesi JA, Nickell M, Brown DP, Hagman DK (2005) Tight temporal consistency of coral mass spawning at the Flower Garden Banks, Gulf of Mexico, from 1997–2003. Gulf Mex Sci 23:107–114Google Scholar
  22. Wallace CC, Babcock RC, Harrison PL, Oliver JK, Willis BL (1986) Sex on the reef: mass spawning of corals. Oceanus 29:38–42Google Scholar
  23. Willis BL, Babcock RC, Harrison PL, Oliver JK (1985) Patterns in the mass spawning of corals on the Great Barrier Reef from 1981 to 1984. Proc 5th Int Coral Reef Congr 4: 343–348Google Scholar

Copyright information

© Springer-Verlag 2009

Authors and Affiliations

  1. 1.Department of Biological SciencesUniversity of CalgaryAlbertaCanada

Personalised recommendations