Polyp bail-out by the coral Astroides calycularis (Scleractinia, Dendrophylliidae)

  • Eduard Serrano
  • Rafel Coma
  • Karina Inostroza
  • Oscar Serrano
Short Communication


Knowledge of reproductive biology is essential for ecological studies on coral population dynamics. The azooxanthellate colonial coral Astroides calycularis is endemic to the western Mediterranean Sea and adjacent Atlantic coasts. Specimens of this species in artificial conditions, an aquarium with enclosed seawater and low food availability, appeared to show an asexual dispersal mechanism. This mechanism consisted of the detachment and release of single, skeletonless polyps from the underlying colony skeleton (i.e., polyp bail-out). While the released free-living polyps regularly showed extended tentacles and most of them survived, they did not show re-attachment to the substrate or any skeleton formation until the end of the experiment, ∼2–3 months after bail-out. Formation of new reproductive colonies, thereby the eventual completion of asexual reproduction through polyp bail-out in A. calycularis, still needs to be confirmed. In addition to sexual reproduction, polyp bail-out may constitute an alternative propagation mechanism during periods of environmental stress, thereby potentially increasing the survival rate of the parental genotype and the dispersal by drifting soft polyps.


Asexual reproduction Stress Global change Azooxanthellate coral Mediterranean Sea 


  1. Arrigoni R, Kitano YF, Stolarski J, Hoeksema BW, Fukami H, Stefani F, Galli P, Montano S, Castoldi E, Benzoni F (2014) A phylogeny reconstruction of the Dendrophylliidae (Cnidaria, Scleractinia) based on molecular and micromorphological criteria, and its ecological implications. Zool Scr 43:661–688CrossRefGoogle Scholar
  2. Bernardello R, Serrano E, Coma R, Ribes M, Bahamon N (2016) A comparison of remote-sensing SST and in situ seawater temperatura in near-shore habitats in the western Mediterranean Sea. Mar Ecol Prog Ser 559:21–34CrossRefGoogle Scholar
  3. Bianchi CN (2007) Biodiversity issues for the forthcoming tropical Mediterranean Sea. Hydrobiologia 580:7–21CrossRefGoogle Scholar
  4. Capel KCC, Migotto AE, Zilberberg C, Kitahara MV (2014) Another tool towards invasion? Polyp “bail-out” in Tubastraea coccinea. Coral Reefs 33:1165CrossRefGoogle Scholar
  5. Casado-Amezúa P, Goffredo S, Templado J, Machordom A (2012) Genetic assessment of population structure and connectivity in the threatened Mediterranean coral Astroides calycularis (Scleractinia, Dendrophylliidae) at different spatial scales. Mol Ecol 21:3671–3685CrossRefPubMedGoogle Scholar
  6. Casado-Amezúa P, Gasparini G, Goffredo S (2013) Phenological and morphological variations in the Mediterranean orange coral Astroides calycularis between two distant localities. Zoology 116:159–167CrossRefPubMedGoogle Scholar
  7. Coma R, Ribes M (2003) Seasonal energetic constraints in Mediterranean benthic suspension feeders: effects at different levels of ecological organization. Oikos 101:205–215CrossRefGoogle Scholar
  8. Di Franco A, Milazzo M, Baiata P, Tomasello A, Chemello R (2009) Scuba diver behaviour and its effects on the biota of a Mediterranean marine protected area. Environ Conserv 36:32–40CrossRefGoogle Scholar
  9. Gambi MC, Barbieri F, Signorelli S, Saggiomo V (2010) Mortality events along the Campania coast (Tyrrhenian Sea) in summers 2008 and 2009 and relation to thermal conditions. Biol Mar Mediterr 17:126–127Google Scholar
  10. Goffredo S, Gasparini G, Marconi G, Putignano MT, Pazzini C, Zaccanti F (2010) Gonochorism and planula brooding in the Mediterranean endemic orange coral Astroides calycularis (Scleractinia: Dendrophylliidae): morphological aspects of gametogenesis and ontogenesis. Mar Biol Res 10:421–436CrossRefGoogle Scholar
  11. Goffredo S, Caroselli E, Gasparini G, Marconi G, Putignano MT, Pazzini C, Zaccanti F (2011) Colony and polyp biometry and size structure in the orange coral Astroides calycularis (Scleractinia: Dendrophylliidae). Mar Biol Res 7:272–280CrossRefGoogle Scholar
  12. Goreau TH, Goreau NI (1959) The physiology of skeleton formation in corals. II. calcium deposition by hermatypic corals under various conditions in the reef. Biol Bull 117:239–250CrossRefGoogle Scholar
  13. Grubelić I, Antolić B, Despalatović M, Grbec B, Paklar BG (2004) Effect of climatic fluctuations on the distribution of warm-water coral Astroides calycularis in the Adriatic Sea: new records and review. J Mar Biol Assoc UK 84:599–602CrossRefGoogle Scholar
  14. Harrison PL (2011) Sexual reproduction of scleractinian corals. In: Dubinsky Z, Stambler N (eds) Coral Reefs: an ecosystem in transition. Springer Netherlands, Dordrecht, pp 59–85CrossRefGoogle Scholar
  15. Houlbrèque F, Ferrier-Pagès C (2009) Heterotrophy in tropical scleractinian corals. Biol Rev 84:1–17CrossRefPubMedGoogle Scholar
  16. Houlbrèque F, Tambutté E, Richard C, Ferrier-Pagès C (2004) Importance of a micro-diet for scleractinian corals. Mar Ecol Prog Ser 282:151–160CrossRefGoogle Scholar
  17. Kariyazono ST, Hatta M (2015) Bail-out of the polyp from the skeleton of spats in the scleractinian coral Acropora tenuis. Galaxea J Coral Reef Stud 17:19–20CrossRefGoogle Scholar
  18. Kružić P (2007) Polyp expulsion of the coral Cladocora caespitosa (Anthozoa, Scleractinia) in extreme sea temperature conditions. Nat Croat 16:211–214Google Scholar
  19. Kružić P, Zibrowius H, Pozar-Domac A (2002) Actiniaria and Scleractinia (Cnidaria, Anthozoa) from the Adriatic Sea: first records, confirmed occurrences and significant range extensions of certain species. Ital J Zool 69:345–353CrossRefGoogle Scholar
  20. Kvitt H, Kramarsky-Winter E, Maor-Landaw K, Zandbank K, Kushmaro A, Rosenfeld H, Fine M, Tchernov D (2015) Breakdown of coral colonial form under reduced pH conditions is initiated in polyps and mediated through apoptosis. Proc Natl Acad Sci U S A 112:2082–2086CrossRefPubMedPubMedCentralGoogle Scholar
  21. Moreno D, de la Linde A, Arroyo MC, López-González PJ (2008) Astroides calycularis (Pallas, 1766). In: Barea-Azcón JM, Ballesteros-Duperón E, Moreno D (eds) Libro rojo de los invertebrados de Andalucía, Tomo 1. Consejería de Medio Ambiente-Junta de Andalucía, Sevilla, pp 281–287Google Scholar
  22. Movilla J, Calvo E, Coma R, Serrano E, López-Sanz À, Pelejero C (2016) Annual response of two Mediterranean azooxanthellate temperate corals to low-pH and high-temperature conditions. Mar Biol 163:135CrossRefGoogle Scholar
  23. Musco L, Prada F, D’Anna G, Galasso NM, Pipitone C, Vega Fernández T, Badalamenti F (2017) Turning casualty into opportunity: fragmenting dislodged colonies is effective for restoring reefs of a Mediterranean endemic coral. Ecol Eng 98:206–212CrossRefGoogle Scholar
  24. Pellón J, Badalamenti F (2016) Tentacular release of planulae in Anthozoa: the case of the Mediterranean endemic orange coral Astroides calycularis (Scleractinia: Dendrophylliidae). Coral Reefs 35:1369CrossRefGoogle Scholar
  25. Rosenfeld M, Bresler V, Abelson A (1999) Sediment as a possible source of food for corals. Ecol Let 2:345–348CrossRefGoogle Scholar
  26. Sammarco PW (1982) Polyp bail-out: an escape response to environmental stress and a new means of reproduction in corals. Mar Ecol Prog Ser 10:57–65CrossRefGoogle Scholar
  27. Shapiro OH, Kramarsky-Winter E, Gavish AR, Stocker R, Vardi A (2016) A coral-on-a-chip microfluidic platform enabling live-imaging microscopy of reef-building corals. Nat Commun 7:10860CrossRefPubMedPubMedCentralGoogle Scholar
  28. Sin LC, Walford J, Goh BPI (2012) The effect of benthic macroalgae on coral settlement. In: Siang TK (ed) Contributions to Marine Science: A commemorative volume celebrating 10 years of research on St John’s Island. National University of Singapore, pp 89–93Google Scholar
  29. Templado J, Calvo M, Luque AA, Garvia A, Maldonado M, Moro L (2004) Guía de los invertebrados y peces marinos españoles protegidos por la legislación nacional e internacional. Ministerio de Medio Ambiente, Serie Técnica, MadridGoogle Scholar
  30. Terrón-Sigler A, León-Muez D, Peñalver-Duque P, Gálvez-César R, Espinosa Torre F (2016a) Geographic distribution of Astroides calycularis (Scleractinia: Dendrophylliidae) as a baseline to assess future human impacts on the Southern Iberian Peninsula. J Mar Biol Assoc UK 96:1181–1189CrossRefGoogle Scholar
  31. Terrón-Sigler A, León-Muez D, Peñalver-Duque P, Espinosa Torre F (2016b) The effects of SCUBA diving on the endemic Mediterranean coral Astroides calycularis. Ocean Coast Manag 122:1–8CrossRefGoogle Scholar
  32. Yuyama I, Ito Y, Watanabe T, Hidaka M, Suzuki Y (2012) Differential gene expression in juvenile polyps of the coral Acropora tenuis exposed to thermal and chemical stresses. J Exp Mar Biol Ecol 430–431:17–24CrossRefGoogle Scholar
  33. Zibrowius H (1995) The “southern” Astroides calycularis in the Pleistocene of the northern Mediterranean–an indicator of climatic change (Cnidaria, Scleractinia). Geobios 28:9–16CrossRefGoogle Scholar

Copyright information

© Senckenberg Gesellschaft für Naturforschung and Springer-Verlag Berlin Heidelberg 2017

Authors and Affiliations

  • Eduard Serrano
    • 1
  • Rafel Coma
    • 1
  • Karina Inostroza
    • 2
  • Oscar Serrano
    • 3
  1. 1.Centre d’Estudis Avançats de Blanes (CEAB-CSIC)BlanesSpain
  2. 2.BMT Oceanica Pty LtdWembleyAustralia
  3. 3.School of Science, Centre for Marine Ecosystems ResearchEdith Cowan UniversityJoondalupAustralia

Personalised recommendations