Auswahl der wissenschaftlichen Literatur zum Thema „Pocilloporidae“

Racks of settlement plates were placed in forereef and backreef sites at three reefs offshore from Cairns (Green, Michaelmas and Upolo Reefs) during winter 1985, summer 1985/86, and winter 1986. Over 2200 spat were recorded on the summer plates, while 61 and 220 spat were found on the winter plates in the two years. Acroporid spat were generally dominant on summer plates, except for Upolo Reef where pocilloporid spat were the most abundant at all times of year. Most spat settling in winter at all reefs were of the family Pocilloporidae. Summer spat settlement showed significant variation in numbers between reefs and between forereef and backreef sites on each reef, with the greatest number on backreef sites. Highest recruitment was at Green Island reef despite the relatively depauperate adult fauna on that reef; this suggests that inter-reef dispersal may be the dominant factor in determining the number of recruits. Hypothesized dispersal paths of coral planulae in the region are derived from data on post- spawning oceanographic conditions, and testable predictions are made for future recruitment patterns in this reef set.

Many coral larvae require surface contact with crustose red algae (CRA) to induce metamorphosis; however, many features of the ecology of pocilloporid corals, such as their ability to colonize primary substrata, suggest that their larvae respond to different cues. We compared the metamorphosis of larvae of the brooding corals Stylophora pistillata (family Pocilloporidae) and Acropora palifera (family Acroporidae) in response to a variety of environmental cues. Acropora palifera metamorphosed only in the presence of three species of CRA. In contrast, S. pistillata metamorphosed in all assays, except those containing the brown alga Lobophora sp. Metamorphosis was highest (80 ± 20%) in unfiltered sea water; however, metamorphosis also occurred in 0.2-μm filtered sea water. These results suggest that S. pistillata larvae respond to both large and small water-borne molecular cues. The lack of a stringent requirement for surface contact with CRA will allow S. pistillata larvae to pre-empt species that require a more developed fouling community to induce metamorphosis and this feature of larval ecology may be the key to understanding the success of many opportunistic benthic species.

Potensi rekruitmen karang sangat penting di dalam pengelolaan terumbu karang, karena potensi pemulihan terumbu karang tergantung pada rekruitmen karang. Penelitian rekruitmen karang Scleractinia dilakukan di perairan Pulau Lembata, Nusa Tenggara Timur, pada bulan Juli 2011. Penelitian ini bertujuan untuk mengetahui keanekaragaman dan kelimpahan rekruit (anakan) karang. Hasil penelitian menunjukkan bahwa Acroporidae, Pocilloporidae, dan Poritidae merupakan tiga famili karang yang mempunyai kontribusi terbesar pada rekruitmen karang di perairan Lembata. Komposisi genus karang pada stasiun penelitian di Laut Flores (Pulau Lapan, Pulau Watupeni, Pulau Wuku) berbeda dari komposisi genus karang di stasiun perairan selat sekitar Pulau Lembata dan Laut Sawu. Ketiga stasiun penelitian di Laut Flores juga mempunyai kelimpahan rekruit yang lebih tinggi dari lokasi lainnya. Kata kunci: karang, rekruitmen, Lembata, komposisi, kelimpahan Potential recruitment of Scleractinian corals is very important in coral reef management, since coral reef recovery is very dependent on coral recruitment. Study on coral recruitment was conducted in Pulau Lembata waters, Nusa Tenggara Timur, on July 2011. Objectives of the study were to determine taxa (family and genera) diversity and abundance of coral recruits. Results showed that coral families of Acroporidae, Pocilloporidae, and Poritidae had highest contribution to the whole coral recruitment. Study locations in the Flores Sea (Pulau Lapan, Pulau Watupeni, Pulau Wuku) showed genera composition that is different from other study locations. The three islands in the Flores Sea also had significantly higher recruit abundance than those in other locations. Key words: coral, recruitment, Lembata, composition, abundance

More than a decade ago, a new mitochondrial Open Reading Frame (mtORF) was discovered in corals of the family Pocilloporidae and has been used since then as an effective barcode for these corals. Recently, mtORF sequencing revealed the existence of two differentiated Stylophora lineages occurring in sympatry along the environmental gradient of the Red Sea (18.5°C to 33.9°C). In the endemic Red Sea lineage RS_LinB, the mtORF and the heat shock protein gene hsp70 uncovered similar phylogeographic patterns strongly correlated with environmental variations. This suggests that the mtORF too might be involved in thermal adaptation. Here, we used computational analyses to explore the features and putative function of this mtORF. In particular, we tested the likelihood that this gene encodes a functional protein and whether it may play a role in adaptation. Analyses of full mitogenomes showed that the mtORF originated in the common ancestor of Madracis and other pocilloporids, and that it encodes a transmembrane protein differing in length and domain architecture among genera. Homology-based annotation and the relative conservation of metal-binding sites revealed traces of an ancient hydrolase catalytic activity. Furthermore, signals of pervasive purifying selection, lack of stop codons in 1830 sequences analyzed, and a codon-usage bias similar to that of other mitochondrial genes indicate that the protein is functional, i.e., not a pseudogene. Other features, such as intrinsically disordered regions, tandem repeats, and signals of positive selection particularly in Stylophora RS_LinB populations, are consistent with a role of the mtORF in adaptive responses to environmental changes.

Pocillopora tuahiniensis sp. nov. is described based on mitochondrial and nuclear genomic data, algal symbiont genetic data, geographic isolation, and its distribution pattern within reefs that is distinct from other sympatric Pocillopora species (Johnston et al. 2022a, b). Mitochondrial and nuclear genomic data reveal that P. tuahiniensis sp. nov. is a unique species, sister to P. verrucosa, and in a clade different from that of P. meandrina (Johnston et al. 2022a). However, the gross in situ colony appearance of P. tuahiniensis sp. nov. cannot easily be differentiated from that of P. verrucosa or P. meandrina at Mo’orea. By sequencing the mtORF region, P. tuahiniensis sp. nov. can be easily distinguished from other Pocillopora species. Pocillopora tuahiniensis sp. nov. has so far been sampled in French Polynesia, Ducie Island, and Rapa Nui (Armstrong et al. 2023; Edmunds et al. 2016; Forsman et al. 2013; Gélin et al. 2017; Mayfield et al. 2015; Oury et al. 2021; Voolstra et al. 2023). On the fore reefs of Mo’orea, P. tuahiniensis sp. nov. is very abundant ≥10 m and is one of the most common Pocillopora species at these depths (Johnston et al. 2022b). It can also be found at a much lower abundance at shallow depths on the fore reef and back reef lagoon. The holotype is deposited at the Smithsonian Institution as USNM-SI 1522390 and the mtORF Genbank accession number is OP418359.

La construction et le maintien des récifs coralliens dépendent essentiellement de la calcification des coraux, organismes qui produisent un squelette rigide fait de CaCO3, sous la forme cristalline d'aragonite. La plupart de ces coraux vivent en symbiose avec des dinoflagellés photosynthétiques de la famille des Symbiodiniaceae, qui fournissent de l'énergie et des nutriments à l'hôte corallien. Compte tenu de l'importance écologique des coraux constructeurs de récifs, de nombreux progrès ont été réalisés dans l'identification des mécanismes à la base de la calcification des coraux. Néanmoins, il existe encore des lacunes importantes dans la compréhension de ce processus, dont la caractérisation des transporteurs d'ions, utilisés par les cellules calcifiantes pour promouvoir la calcification. Pour contribuer à ce manque de connaissances, des approches ciblées et générales, couplées à des outils moléculaires et bioinformatiques, ont été utilisées tout au long de cette thèse. En utilisant l'approche ciblée, j'ai recherché, dans le génome et le transcriptome du corail symbiotique Stylophora pistillata, des protéines de transport d'ions, précédemment rapportées comme étant impliquées dans la calcification d'autres espèces calcifiantes. En utilisant une approche générale, j'ai étendu la recherche de gènes candidats chez le corail non symbiotique Tubastraea spp. Les deux approches ont contribué à une meilleure compréhension des mécanismes de transport d'ions utilisés par les cellules calcifiantes du corail pour favoriser la calcification dans ce groupe d'animaux marins écologiquement important
The construction and maintenance of coral reefs primarily depends on the calcification of corals, which produce a rigid skeleton made of CaCO3 in the crystalline form of aragonite. Most reef-building corals live in symbiosis with photosynthetic dinoflagellates of the Symbiodiniaceae family, which provide the coral host with energy and nutrients. Given their ecological importance, much progress has been made in identifying key elements of the mechanisms underlying coral calcification. Nevertheless, there are still significant gaps in our understanding. Foremost is the characterization of ion transporters, used by the coral calcifying cells to promote calcification. To contribute to this lack of knowledge, targeted and broad approaches, coupled with molecular and bioinformatics tools, have been used throughout this thesis. Using the targeted approach, ion transporter proteins, previously reported to be involved in calcification of other calcifying species, have been identified for the first time in the genome and transcriptome of the symbiotic coral Stylophora pistillata. Whereas, using a broad approach, novel candidate genes for roles in calcification have been identified in the non-symbiotic coral Tubastraea spp. Overall, both approaches contributed to a better understanding of the ion transporting mechanisms used by the coral calcifying cells to promote calcification in this ecologically important group of marine animals

Corals are able to source autotrophically-produced carbon since they have symbiotic unicellular dinoflagellates embedded in their tissue. However, they are also known to be heterotrophic feeders and able to ingest a variety of food sources, such as bacteria, particulate organic matter and zooplankton. Recent research has shown that heterotrophic feeding has a marked effect on both maintenance and growth in corals by providing mainly a nutritional source of nitrogen and phosphorus. Nevertheless, no study has yet been undertaken on the interactions between feeding and sexual reproduction in corals. This study examines the effects of heterotrophic feeding on the sexual reproduction of Pocillopora verrucosa in aquaria. Rotifers were used as live food source at two concentrations (LFC = low feed colonies) = 5×102 organisms/L; (HFC = high feed colonies) = 15×102 organisms /L) and an unfed control (UC = unfed colonies) was added for comparison. Three replicates of five colonies were used for each food concentration and control. Rotifers were distributed among the nine aquaria four times per week for three hours. Histological sections of coral polyps were prepared to monitor the development of gametogenic stages and the fecundity of the colonies. The number and size of oocyte, and spermary stages were determined in each polyp. Both fed and starved colonies proved to be simultaneous hermaphrodites and broadcast spawners. The gametogenesis period was short and occurred from October to December 2007. No spawning event was observed in the aquaria. However, the disappearance of mature oocytes in samples collected in January 2008 suggested that spawning took place between December 2007 and January 2008. Heterotrophic feeding had a strong effect on reproduction in P.verrucosa. The results showed that both the proportion of polyps with gametes and the reproductive effort were lower in the fed than in starved colonies. It is likely that an energetic trade-off occurred between reproduction and other metabolic functions. However, oocytes were bigger in fed corals compared with the unfed controls. Several hypotheses are proposed to explain these metabolic/energy distribution patterns.
Thesis (M.Sc.)-University of KwaZulu-Natal, Westville, 2009.

博士
臺灣大學
海洋研究所
96
In this dissertation, I focus on the study of mitochondrial genome (mitogenome) of the scleractinian family Pocilloporidae to address two main evolutionary issues. Firsty, the slow-evolution hypothesis of anthozoan mitochondrial (mt) DNA was evaluated by comparing mitogenomes of 2 sibling (sister) coral species. Secondly, the evolutionary phylogeny of the Pocilloporidae was investigated by mitogenomic analyses. The complete mitochondrial genomes of 2 sibling (sister) Seriatopora species were first sequenced and determined in order to verify the slow evolution of anthozoan mtDNA (Chapter 3). Afterward different mtDNA regions were evaluated by analyzing variations and divergences within and between populations of the same species and by comparisons between 2 Seriatopora species. Gene arrangement of the Seriatopora mitogenomes is similar to the currently published scleractinian mitogenomes with the exception of three eclusive features, including gene atp8, a duplicated trnW (tRNATRP), and a putative control region located between atp6 and nad4. The significances of a highest value in between-species variation and a lowest one in within-population comparison showed several protein-coding genes and intergenic spacers could provide phylogenetic information in discerning among recently-diverged populations or boundaries of delineating species. Phylogenetic analyses of the hypervariable regions for the Indo-West Pacific populations also revealed a monophyly of the Andaman-Sea Seriatopora, which is suggested to be separated geographically since 3 million years ago. Evaluation of the molecular evolution of atp6 and the putative control region showed 2- to 7-fold higher divergence rates among populations or between species than those published for scleractinian mitogenomes. This study not only successfully reveals the phylogenies of Se. hystrix and Se. caliendrum from the West Pacific Ocean by mtDNA of the 9th intergenic spacer, putative control region, atp6, and the cox1 genes, but also highlights the potential utility of hypervariable regions of mt phylogenetic tree construction for Seriatopora below the species level. The hypothesis of slow evolution of anthozoan mtDNA should be treated with caution, since the evolutionary rate of the mitogenomes could be highly variable among different genes and intergenic spacers, and even in different scleractinian lineages. Since unique mt features were detected in Seriatopora corals, I extended the determination of complete mitogenomes to three confamilial genera in order to understand whether these mt characteristics are also present in other pocilloporid corals (Chapter 4). The mitogenomes of the Madracis formosa, Pocillopora damicornis, and Stylophora pistillata were amplified and determined. The entire mitogenomes of pocilloporid corals ranged from 16,951 to 17,426 bp with the A+T contents ranging from 68.3% to 70.1%. The gene order of protein-coding genes was identical to those of other scleractinian corals. The novel atp8 gene, first described in Seriatopora corals, was also confirmed using RT-PCR, Northern blot, and sequence analyses in other genera of the Pocilloporidae. The intergenic spacer between atp6 and nad4, containing distinct repeated elements, conserved sequence blocks and domains, and functional structures, possesses typical characteristics of a putative control region for the four coral genera. A duplicated trnW, detected in the region close to the cox1 which shares the highly conserved primary and secondary structures of its original counterpart, was discovered in both Seriatopora and Stylophora. These molecular characteristics are unique and provide phylogenetic information for future evaluation of the status of the family Pocilloporidae in the evolutionary history of scleractinian corals. The phylogenetic status of the pocilloporid corals were revised in various aspects according to the mt system (Chapter 5). Different approaches, such as differences in amino-acid usage and molecular phylogeny of 13 protein-coding genes, were utilized to clarify the unsolved discordance between traditional taxonomy and former molecular phylogeny. My results support the former phylogenetic evidence of rDNA sequence. Results of the amino-acid usage and the phylogenetic analyses indicated that the extant Scleractinia was polyphyletically distributed into 3 separate clades, including pocilloporid, complex- and robust-clade corals. The pocilloporid was jointed as a sister clade to robust-clade corals, indicating its most recent common ancestor with robust clade rather than the implicated relationship in conventional taxonomy. Molecular-dating analysis of the phylogenetic trees was used to estimate the development of the pocilloporid lineage. The molecular-dating analysis showed a 330 million years (MY) divergence between the pocilloporid and the robust-clade corals, which is about 100 MY earlier than the oldest fossil Astrocoeniina (middle Triassic). After examining several possible key factors, I suggest that the discrepancy between the oldest fossil record and the molecular-dating estimate may be an evidence of the “naked-coral” hypothesis. The soft-bodied Pocilloporidae (Astrocoeniina) group might have diverged from the robust-clade scleractinian during in the Carboniferous (about 330 Ma), then evolved their skeleton later in the Triassic. Comparisons of mitogenome size, nucleotide composition, and initiation/termination of protein-coding genes indicate that scleractinians could be separated into 3 groups which were concordant with previous studies (Chapter 6). Based on the results of mitogenomic analyses, the Pocilloporidae was deeply diverged from the robust clade and could be considered a distinct lineage of scleractinian corals, in addition to the 2 scleractinian clades by former molecular evidences. The taxonomic status within the Astrocoeniina was also discussed.

碩士
國立中山大學
海洋生物研究所
95
Three brooding corals, Seriatopora hystrix, Stylophora pistillata, and Pocillopora damicornis in Nanwan Bay, southern Taiwan, revealed a diel rhythm of larval release. Planulation by S. hystrix and S. pistillata was highly synchronized with one peak of planula release occurring close to sunrise. Planulae of P. damicornis were released throughout the day with two peaks occurred in the early morning and at night. We maintain corals in laboratory with varied light-dark cycle and temperature to determine the mechanism of their release rhythm. S. hystrix did not release larvae under constant light and constant dark, thus the release of larvae in S. hystrix is not controlled by an endogenous rhythm. Peak of larval release occurs after 23hrs of light cue and under the dark. Temperature treatments, in 1℃ intervals from 23.5-28.5℃, did not change the timing of larval release. We infer that the diel rhythm of larval release of S. hystrix controlled by sunrise. S. pistillata did not release larvae under constant light and constant dark. The larval release pattern of S. pistillata is similar to S. hystrix. Thus, we infer that sunrise may be the cues for the diel rhythm of larval release of S. pistillata. P. damicornis releases larvae under constant light and constant dark, and exhibit a rhythm of larval release with 37 h periodicity under constant dark. The regulation of its larval release is complex. These results suggest that the interspecific mechanism controlling diel rhythm of larval release may be different.

This dissertation characterizes the genetic diversity and thermal tolerance of the coral holobiont Stylophora pistillata and Pocillopora verrucosa (family Pocilloporidae) across the Saudi Arabian Red Sea coast (~1500 km). The population genetic structure and holobiont diversity was assessed using genome-wide single nucleotide polymorphisms (SNPs) identified with reference genome-based RAD-Seq, while the associated microbial communities of the algal symbiont (Symbiodiniaceae) and bacteria were inferred from metabarcoding analyses of the ITS2 and 16S rRNA gene. Thermal tolerance of Stylophora pistillata colonies was assessed using standardized short-term heat stress assays on the novel Coral Bleaching Automated Stress System (CBASS). Chapter 1 details the assembly and annotation of the P. verrucosa genome (~380 Mbp; 27,439 gene models), which was highly complete and compared well to the already available S. pistillata genome. Chapter 2 presents population genetic analyses of both coral species, which revealed pronounced differences in their population genetic structure. While P. verrucosa seemed to be highly connected across the Red Sea basin with the exception of the far south, S. pistillata depicted a complex population genetic structure. Microbial communities of Symbiodiniaceae and bacteria were overall less diverse in P. verrucosa than in S. pistillata, and followed an association pattern that was partly determined by the environment and partly by host genotype. Chapter 3 identifies thermally tolerant S. pistillata genotypes by comparing the heat stress response of colonies collected at two sites within the same reef. Ex-situ heat-stress assays confirmed that colonies from the more temperature stable site (fore reef) were less thermally tolerant than their conspecifics from the back reef, where the diel temperature is more variable. This chapter also highlights the utility of acute heat-stress assays as a tool to identify thermotolerant colonies. Taken together, the work of this dissertation provides a foundation for coral conservation in the Red Sea. It highlights that the genetic structure differs between coral species, suggesting that effective conservation through marine protected areas need to incorporate data from multiple species. Coral population genetic data should further be complemented by thermal tolerance assays across the Red Sea to associate genetic diversity with patterns of heat stress tolerance.

The worldwide market for ornamental saltwater invertebrates supplies the needs of millions of aquarium hobbyists, public exhibitions (i.e., zoos) universities and research institutions. With respect to reef building corals, it is estimated that more than half a million coral colonies/year from a total 93 genera, were exported globally during the period of 1985-1997. International value of retail sale of live coral trade alone is estimated as $78 million in 1997 (not including the illegally, widely smuggled material). The continuous, large-scale collection of marine organisms is responsible, in many places, for the destruction of coral reefs. The expected expansion of the trade further threatens these fragile habitats. While no true captive-bred corals are commercially available, our long-term goal is to develop ex situ inland farming of coral colonies that will circumvent the need for in situ collections and will provide domesticated specimens for the trade and for research. We simultaneously studied two model branching coral species, Stylophora pistillata (Pocilloporidae; in Israel) and Porites (Poritidae; in the US). The proposal included three specific aims: (a) To develop protocols for nubbins (small fragments, down to the size of a single polyp) usage in coral farming;(b) To address the significance of colony pattern formation to the coral trade; and (c) To develop the protocols of using nubbins in physiological and ecotoxicological assays (using oil dispersants, the expression of the stress protein HSP-70, household detergents, etc.). Ten scientific publications (published manuscripts, accepted for publications, submitted to scientific journals, in preparation), revealing results that were related to all three specific aims, originated from this BARD proposal. As a result of the work supported by the BARD, we have now, in hand, original and improved protocols for coral maintenance ex situ, proven expertise on manipulating coral colonies’ pattern formation and biological knowledge on island mariculture of reef corals (from Hawaii and from the Red Sea) amenable for the ornamental trade (for public and private aquaria use, for experimentation). At least one Israeli company (Red Sea Corals, Ltd., KibbutzSaar) is using our methodologies for further developing this new mariculture sector. We are now in the process of introducing the rationale and methodologies to Hawaiian private entities to expand dissemination of the research outcomes.