The annual growth rate of the solitary coral Fungia scutaria Lamarck was determined by observed increases in skeletal length and width. Growth was followed for periods varying from 7.5 to 9.0 months during 1963 and 1964. Measurements were made in situ at the center of fungid distribution in Kaneohe Bay, Oahu, where there exists an aggregation of Fungia which is atypically dense for the Hawaiian Islands. Although this bay provides a relatively optimal environment for the growth of Fungia, as demonstrated by their abundance and increased rate of growth, variations in growth rate is apparently as erratic here as in other areas. Growth curves, constructed for various arbitrarily selected size-classes of Fungia, confirm earlier observations of greater rates of skeletal growth in the smaller corals. The results of this study indicate the necessity of basing reliable estimates of coral growth rate upon an adequate sampling, taking into account the past history and size of the corals measured.

Typescript. / Thesis (Ph. D.)--University of Hawaii, 1966. / Bibliography: leaves [124]-130. / xiv, 130 leaves ill

One of the main focus of coral reef ecology has been to shed light on the importance of all microbial members of coral holobiont and how their interactions contribute to the coral’s resilience. However, knowledge is lacking about the composition of microbial communities inhabiting the surface mucus layer of corals including Fungia fungites, a species that lives under stressful conditions close to fish farms in Vietnam. I investigated the prokaryotic communities that are thriving in Fungia fungites surface mucus layer (SML) in the wild and how they were affected upon antibiotics and nitrogen stress using 16S rRNA gene-based techniques. Firstly, I observed a significant alteration in the composition of microbial communities due to antibiotics effect, with exposed communities featuring lower richness and α-diversity in contrast to the controls. Further, mucosal microbial communities were found to be mostly dominated by Proteobacteria (especially of the classes of Alphaproteobacteria and Gammaproteobacteria) and less by Bacteroidetes (Flavobacteriia). Results from this study suggest a developed antibiotic resistance of Alteromonadales and Campylobacterales indicated by their increased abundance upon antibiotics effect. Moving forward, future studies should focus on exploring also the contribution of non-prokaryotic microbial members of Fungia fungites holobiont and how antibiotic resistance can potentially influence coral’s health. The results support that Fungia fungites SML microbial communities are strongly affected by antibiotics exposure and call for future research to focus on the function of these microbial communities and how they can contribute to the coral’s resilience.

Looking at the metabolite profile of an organism provides insights into the metabolomic state of a cell and hence also into pathways employed. Little is known about the metabolites produced by corals and their algal symbionts. In particular, corals from the central Red Sea are understudied, but interesting study objects, as they live in one of the warmest and most saline environments and can provide clues as to the adjustment of corals to environmental change. In this study, we applied gas chromatography – mass spectrometry (GC–MS) metabolite profiling to analyze the metabolic profile of four coral species and their associated symbionts: Fungia granulosa, Acropora hemprichii, Porites lutea, and Pocillopora verrucosa. We identified and quantified 102 compounds among primary and secondary metabolites across all samples. F. granulosa and its symbiont showed a total of 59 metabolites which were similar to the 51 displayed by P. verrucosa. P. lutea and A. hemprichii both harbored 40 compounds in conjunction with their respective isolated algae. Comparing across species, 28 metabolites were exclusively present in algae, while 38 were exclusive to corals. A principal component and cluster analyses revealed that metabolite profiles clustered between corals and algae, but each species harbored a distinct catalog of metabolites. The major classes of compounds were carbohydrates and amino acids. Taken together, this study provides a first description of metabolites of Red Sea corals and their associated symbionts. As expected, the metabolites of coral hosts differ from their algal symbionts, but each host and algal species harbor a unique set of metabolites. This corroborates that host-symbiont species pairs display a fine-tuned complementary metabolism that provide insights into the specific nature of the symbiosis. Our analysis also revealed aquatic pollutants, which suggests that metabolite profiling might be used for monitoring pollution levels and assessing environmental impact.