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Over the next 30 to 40 years, rising ocean temperatures and increased ocean acidification have the potential to overpower the vast majority of current in situ coral conservation efforts, resulting in severe loss of reef biodiversity. If this occurs, ex situ coral conservation incorporating cryopreservation may provide an important means for successful reef diversification. To build new tools for the continued protection and propagation of coral, an international group of coral and cryopreservation scientists known as the Reef Recovery Initiative joined forces. The outcome was the creation of the first frozen bank for Australian, Caribbean and Hawaiian coral, containing 8 important reef-building species including, Acropora tenuis, Acropora millepora, Acropora loripes, Platygyra daedalea, Platygyra lamolina, Fungia scutaria, Acropora palmata and Acropora cervicornis. Most species of coral are hermaphrodites and reproduce sexually by producing lipid-rich egg/sperm bundles. Generally, self-fertilization is low. A simple, uniform freezing method (10% Me2SO in seawater with a freezing rate of 20°C/min) was devised to cryopreserve the sperm of all these species. Coral reproduction is driven by access to sunlight, which powers the intracellular algae to produce complex sugars for the coral. In turn, the coral use these sugars to build lipids needed for the germplasm. Even though we found a unified method for sperm cryopreservation in coral there were physiological challenges. For example, sperm production across the complex web of polyps in single genetic individuals varied. Specifically, in 2011 egg/sperm bundles with more eggs produced more motile sperm. This variation may have been caused by polyp age, prior damage, access to sunlight or a combination of factors. An additional challenge was a ‘night-of-preservation’ effect whereby some nights the sperm preservation from pooled colonies produced widely differing post-thaw motility, as well as cryopreservation and fertilization success. Finally, when this simple sperm cryopreservation method was used on the Hawaiian acroporid, Montipora captitata, it consistently produced low post-thaw motility and no fertilization success. This species was found to have a toxin in the adult tissue that it transferred to the eggs and possibly the sperm prior to reproduction. Therefore, the release of this toxin from slightly damaged sperm cells may have impacted these post-thaw results, and may ultimately inhibit the successful cryopreservation of this species. Finally, coral larvae have not been successfully cryopreserved because of their exquisite chilling sensitivity. Nevertheless, pluripotent 8-cell embryos were successfully dissociated, frozen and thawed with 50 to 90% intact cells post-thaw in all species tested. Frozen and thawed coral sperm can now be used to create new coral, as they develop, settle and take up their intracellular algae. In the near future, we may have a blueprint to move our work from the laboratory to the reefs to develop collaborative, practical conservation management tools to secure reef biodiversity. Source of funding: This work was supported by the Roddenberry Foundation, Matthew Frank Foundation, Taronga Conservation Society Australia, Australian Institute of Marine Science, Anela Kolohe Foundation, Hawaii Institute of Marine Biology and the Smithsonian Institution. Conflict of interest: None declared. hagedornm@si.edu [ABSTRACT FROM AUTHOR]

The article reports on the discovery of scientists from the Australian Institute of Marine Science (AIMS) to a reproductive strategy on corals that would add another dimension to the complex life cycles of corals. It shows that coral offspring has distinct ability to generate genetic clones of themselves prior to their development into adult corals. It implies that complexity in the behaviour of corals suggest more learnings about the lives of corals and their interaction to the environment.

The article discusses the coral rehabilitation and spawning by outplanted corals in Okinawa, Japan. It states the rearing method for outplants and scleractinian coral species that was permitted by Okinawa Prefecture. An overview on the extensive synchronous spawning of outplanted Acropora tenuis, is also emphasized.

Presents an article concerning multispecific, synchronous coral spawning in Singapore.

The future of coral reefs under increasing CO 2 depends on their capacity to recover from disturbances. To predict the recovery potential of coral communities that are fully acclimatized to elevated CO 2 , we compared the relative success of coral recruitment and later life stages at two volcanic CO 2 seeps and adjacent control sites in Papua New Guinea. Our field experiments showed that the effects of ocean acidification (OA) on coral recruitment rates were up to an order of magnitude greater than the effects on the survival and growth of established corals. Settlement rates, recruit and juvenile densities were best predicted by the presence of crustose coralline algae, as opposed to the direct effects of seawater CO 2 Offspring from high CO 2 acclimatized parents had similarly impaired settlement rates as offspring from control parents. For most coral taxa, field data showed no evidence of cumulative and compounding detrimental effects of high CO 2 on successive life stages, and three taxa showed improved adult performance at high CO 2 that compensated for their low recruitment rates. Our data suggest that severely declining capacity for reefs to recover, due to altered settlement substrata and reduced coral recruitment, is likely to become a dominant mechanism of how OA will alter coral reefs., (© 2017 The Author(s).)

Reproductive timing in brooding corals has been correlated to temperature and lunar irradiance, but the mechanisms by which corals transduce these environmental variables into molecular signals are unknown. To gain insight into these processes, global gene expression profiles in the coral Pocillopora damicornis were examined (via RNA-Seq) across lunar phases and between temperature treatments, during a monthly planulation cycle. The interaction of temperature and lunar day together had the largest influence on gene expression. Mean timing of planulation, which occurred at lunar days 7.4 and 12.5 for 28- and 23°C-treated corals, respectively, was associated with an upregulation of transcripts in individual temperature treatments. Expression profiles of planulation-associated genes were compared between temperature treatments, revealing that elevated temperatures disrupted expression profiles associated with planulation. Gene functions inferred from homologous matches to online databases suggest complex neuropeptide signalling, with calcium as a central mediator, acting through tyrosine kinase and G protein-coupled receptor pathways. This work contributes to our understanding of coral reproductive physiology and the impacts of environmental variables on coral reproductive pathways., (© 2017 John Wiley & Sons Ltd.)

Successful reproduction and larval dispersal are important for the persistence of marine invertebrate populations, and these early life history processes can be sensitive to marine pollution. Coal is emerging as a contaminant of interest due to the proximity of ports and shipping lanes to coral reefs. To assess the potential hazard of this contaminant, gametes, newly developed embryos, larvae and juveniles of the coral Acropora tenuis were exposed to a range of coal leachate, suspended coal, and coal smothering treatments. Fertilisation was the most sensitive reproductive process tested. Embryo survivorship decreased with increasing suspended coal concentrations and exposure duration, effects on larval settlement varied between treatments, while effects on juvenile survivorship were minimal. Leachate exposures had negligible effects on fertilisation and larval settlement. These results indicate that coral recruitment could be affected by spills that produce plumes of suspended coal particles which interact with gametes and embryos soon after spawning., (Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.)

The article reports on the restoration of Acropora cervicornis coral at T/V Margara grounding site in Tallaboa, Puerto Rico following damage caused by an oil tanker on April 27, 2006. Topics discussed include the successful restoration on the reef, the outplanting Acropora cervicornis, the development of self-sustaining thicket, and the existence of Acropora cervicornis colonies.

The persistence of natural metapopulations may depend on subpopulations that exist at the edges of species ranges, removed from anthropogenic stress. Mesophotic coral ecosystems (30-150 m) are buffered from disturbance by depth and distance, and are potentially massive reservoirs of coral diversity and fecundity; yet we know little about the reproductive capabilities of their constituent species and the potential for these marginal environments to influence patterns of coral reef persistence. We investigated the reproductive performance of the threatened depth-generalist coral Orbicella faveolata over the extent of its vertical range to assess mesophotic contributions to regional larval pools. Over equal habitat area, mesophotic coral populations were found to produce over an order of magnitude more eggs than nearby shallow populations. Positive changes with depth in both population abundance and polyp fecundity contributed to this discrepancy. Relative larval pool contributions of deeper living corals will likely increase as shallow habitats further degrade due to climate change and local habitat degradation. This is a compelling example of the potential for marginal habitat to be critical to metapopulation persistence as reproductive refugia. [ABSTRACT FROM AUTHOR]

The sexual pattern, reproductive mode, and timing of reproduction of Isophyllia sinuosa and Isophyllia rigida , two Caribbean Mussids, were assessed by histological analysis of specimens collected monthly during 2000-2001. Both species are simultaneous hermaphroditic brooders characterized by a single annual gametogenetic cycle. Spermatocytes and oocytes of different stages were found to develop within the same mesentery indicating sequential maturation for extended planulation. Oogenesis took place during May through April in I. sinuosa and from August through June in I. rigida . Oocytes began development 7-8 months prior to spermaries but both sexes matured simultaneously. Zooxanthellate planulae were observed in I. sinuosa during April and in I. rigida from June through September. Higher polyp and mesenterial fecundity were found in I. rigida compared to I. sinuosa . Larger oocyte sizes were found in I. sinuosa than in I. rigida , however larger planula sizes were found in I. rigida . Hermaphroditism is the exclusive sexual pattern within the Mussidae while brooding has been documented within the related genera Mussa , Scolymia and Mycetophyllia . This study represents the first description of the sexual characteristics of I. rigida and provides an updated description of I. sinuosa ., Competing Interests: The authors declare that they have no competing interests.

Larval production and recruitment underpin the maintenance of coral populations, but these early life history stages are vulnerable to extreme variation in physical conditions. Environmental managers aim to minimise human impacts during significant periods of larval production and recruitment on reefs, but doing so requires knowledge of the modes and timing of coral reproduction. Most corals are hermaphroditic or gonochoric, with a brooding or broadcast spawning mode of reproduction. Brooding corals are a significant component of some reefs and produce larvae over consecutive months. Broadcast spawning corals are more common and display considerable variation in their patterns of spawning among reefs. Highly synchronous spawning can occur on reefs around Australia, particularly on the Great Barrier Reef. On Australia's remote north-west coast there have been fewer studies of coral reproduction. The recent industrial expansion into these regions has facilitated research, but the associated data are often contained within confidential reports. Here we combine information in this grey-literature with that available publicly to update our knowledge of coral reproduction in WA, for tens of thousands of corals and hundreds of species from over a dozen reefs spanning 20° of latitude. We identified broad patterns in coral reproduction, but more detailed insights were hindered by biased sampling; most studies focused on species of Acropora sampled over a few months at several reefs. Within the existing data, there was a latitudinal gradient in spawning activity among seasons, with mass spawning during autumn occurring on all reefs (but the temperate south-west). Participation in a smaller, multi-specific spawning during spring decreased from approximately one quarter of corals on the Kimberley Oceanic reefs to little participation at Ningaloo. Within these seasons, spawning was concentrated in March and/or April, and October and/or November, depending on the timing of the full moon. The timing of the full moon determined whether spawning was split over two months, which was common on tropical reefs. There were few data available for non-Acropora corals, which may have different patterns of reproduction. For example, the massive Porites seemed to spawn through spring to autumn on Kimberley Oceanic reefs and during summer in the Pilbara region, where other common corals (e.g. Turbinaria & Pavona) also displayed different patterns of reproduction to the Acropora. The brooding corals (Isopora & Seriatopora) on Kimberley Oceanic reefs appeared to planulate during many months, possibly with peaks from spring to autumn; a similar pattern is likely on other WA reefs. Gaps in knowledge were also due to the difficulty in identifying species and issues with methodology. We briefly discuss some of these issues and suggest an approach to quantifying variation in reproductive output throughout a year.

The article offers information on the Pavona decussata which is a massive colony of corals located at Tatsukushi Marine Park in Kochi Prefecture, Japan. Topics discussed include the sexual activeness of Pavona decussata, egg releasing, and genotypes. Also mentioned are buoyant sperm, larvae, and age and measurement of the corals.

A comprehensive understanding of coral reproduction and development is needed because corals are threatened in many ways by human activity. Major threats include the loss of their photosynthetic symbionts (Symbiodinium) caused by rising temperatures (bleaching), reduced ability to calcify caused by ocean acidification, increased storm severity associated with global climate change and an increase in predators caused by runoff from human agricultural activity. In spite of these threats, detailed descriptions of embryonic development are not available for many coral species. The current consensus is that there are two major groups of stony corals, the "complex" and the "robust". In this paper we describe the embryonic development of four "complex" species, Pseudosiderastrea tayamai, Galaxea fascicularis, Montipora hispida, and Pavona Decussata, and seven "robust" species, Oulastrea crispata, Platygyra contorta, Favites abdita, Echinophyllia aspera, Goniastrea favulus, Dipsastraea speciosa (previously Favia speciosa), and Phymastrea valenciennesi (previously Montastrea valenciennesi). Data from both histologically sectioned embryos and whole mounts are presented. One apparent difference between these two major groups is that before gastrulation the cells of the complex corals thus far described (mainly Acropora species) spread and flatten to produce the so-called prawn chip, which lacks a blastocoel. Our present broad survey of robust and complex corals reveals that prawn chip formation is not a synapomorphy of complex corals, as Pavona Decussata does not form a prawn chip and has a well-developed blastocoel. Although prawn chip formation cannot be used to separate the two clades, none of the robust corals which we surveyed has such a stage. Many robust coral embryos pass through two periods of invagination, separated by a return to a spherical shape. However, only the second of these periods is associated with endoderm formation. We have therefore termed the first invagination a pseudo-blastopore. [ABSTRACT FROM AUTHOR]

The article examines the coral reefs at the isolated Gambier Islands in French Polynesia by the Tara Oceans expedition in mid-2011. It mentions the typical feature of the reef pinnacles which involves dense aggregations of large free-living fungiids. It notes the dominance of aggregations on pinnacle tops and upper slopes in Danafungia scruposa and Lithophyllon repanda mushroom corals. It also emphasizes that the aggregations are attributed to local sexual reproduction rather than cloning.

The article offers information on the absence of skeleton deposition among experimental Acropora millepora 30 days after spawning. It states that A. millepora was the first description of non-skeleton depositing in juveniles of scleractinian corals, wherein, the reason for the lack of skeleton formation remains unknown. It suggests that the cause of the phenomenon is likely the epigenetic origin.

The article discusses the settlement of cleaving coral embryos as particles in reef ecosystems, with particular focus on the role of winds in creating sea waves capable of fragmenting embryos in early stages of development into groups of cells or blastomeres. Fertilized coral eggs are vulnerable to the effects of turbulence because they lack the protective embryonic envelope of echinoderms. It is suggested that the clonal propagation of coral embryos occurs in response to sea winds.

The article reports that the mushroom coral, Halomitra clavator, has high population density in West Halmahera, Indonesia, which is existing in four out of 39 observed coral reef cites during a biodiversity survey. It says that the survey was conducted by the Research Center for Oceanography of the Indonesian Institute of Sciences which revealed mushroom corals at 18-20 meters deep and growing on up to three layers of corals. It also provides photographs of mushroom corals.

The article reports on the new way to grow coral colonies in nurseries made of rope discovered in the Philippines by the National Institute of Oceanography and University of Haifa researchers.

The article reports on a study related to the release of eggs from tentacles of stephanocoenia intersepta coral. It offers information on the process of spawning where polyps held between one and five eggs in each tentacle, with a slit extending over the length of each tentacle, so that the eggs can be exposed to the ambient seawater prior to release. However, the described strategy could increase fertilization success by using 'open' tentacles that can be fertilized simultaneously.

This article discusses research, presented in a 2008 issue of the "Proceedings of the Royal Society B," indicating that the wild mushroom coral can change its sex. This tendency relates to the size of the coral, with medium sized corals able to change their sex bidirectionally. The article comments on the frequency of coral sex changes.

We document long-term effects of a simulated bleaching event on the reproductive output and offspring viability of the soft coral Lobophytum compactum. Corals were subjected to temperature and solar radiation treatments to produce both moderately (48-60%) and heavily (90-95%) bleached colonies. Although bleached colonies recovered their zooxanthellae within 10 to 18 weeks, impacts on reproductive output were significant for at least two annual spawning seasons. In the first year, both polyp fecundity and mean oocyte diameter were reduced and inversely correlated with the degree of bleaching, with complete failureof fertilization in the group of heavily bleached colonies. For moderately bleached soft corals, survival and growth of sexual offspring did not differ significantly from those of unbleached colonies. Although no further reductions in zooxanthellae densities in experimental soft corals were recorded throughout the subsequent second year, egg size and fecundity of the heavily bleached soft corals were still significantly reduced 20 months later. Severe bleaching clearly has long-term sub-lethal impacts, reducing overall reproductive output for atleast two spawning seasons. [ABSTRACT FROM AUTHOR]

Experimental bleaching reduces the levels of important biochemical parameters in adult tissues and eggs of the soft coral Lobophytum compactum. Protein, lipid, mycosporine-like amino acids (MAAs) and carotenoid concentrations remained lower in bleached adults than in controls for at least 8 months. Reductions in concentrations of all four parameters were greater in eggs than in maternal tissues, potentially jeopardizing egg and larval viability. In particular, reductions in lipids, proteins and carotenoids in tissues of heavily bleached soft corals were amplified approximately twofold in eggs. In comparison, amplification of maternal tissue reductions were not as great for MAAs, suggesting that MAAs are given higher priority in egg provisioning. Our finding that MAA levels are normally three times higher in eggs than in unbleached maternal tissues supports the importance of MAAs for larval survival. Twenty months after experimental bleaching the biochemical composition of both adult tissues and their eggs were indistinguishable from those of control (unbleached) soft corals. [ABSTRACT FROM AUTHOR]