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

• Published in: Marine biodiversity Vol. 48; no. 3; pp. 1661 - 1665
• Main Authors: Serrano, Eduard, Coma, Rafel, Inostroza, Karina, Serrano, Oscar
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.09.2018; Springer Nature B.V
• Subjects: Animal Systematics/Taxonomy/Biogeography; Aquaria; Aquarium fishes; Aquariums; Asexual reproduction; Astroides calycularis; Biodiversity; Biology; Biomedical and Life Sciences; Colonies; Corals; Dispersal; Dispersion; Ecological studies; Environmental stress; Experiments; Food; Food availability; Food supply; Freshwater & Marine Ecology; Genotypes; Life Sciences; Plant Systematics/Taxonomy/Biogeography; Polyps; Population dynamics; Population studies; Reproduction; Salinity; Seawater; Sexual reproduction; Short Communication; Substrates; Survival; Tentacles; Asexual reproduction; Azooxanthellate coral; Mediterranean Sea; Stress; Global change
• ISSN: 1867-1616; 1867-1624
• DOI: 10.1007/s12526-017-0647-x

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.