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Background: Molecular phylogenetic studies on scleractinian corals have shown that most taxa are not reflective of their evolutionary histories. Based principally on gross morphology, traditional taxonomy suffers from the lack of well-defined and homologous characters that can sufficiently describe scleractinian diversity. One of the most challenging clades recovered by recent analyses is 'Bigmessidae', an informal grouping that comprises four conventional coral families, Faviidae, Merulinidae, Pectiniidae and Trachyphylliidae, interspersed among one another with no apparent systematic pattern. There is an urgent need for taxonomic revisions in this clade, but it is vital to first establish phylogenetic relationships within the group. In this study, we reconstruct the evolutionary history of 'Bigmessidae' based on five DNA sequence markers gathered from 76 of the 132 currently recognized species collected from five reef regions in the central Indo-Pacific and the Atlantic. Results: We present a robust molecular phylogeny of 'Bigmessidae' based on the combined five-gene data, achieving a higher degree of resolution compared to previous analyses. Two Pacific species presumed to be in 'Bigmessidae' are more closely related to outgroup clades, suggesting that other unsampled taxa have unforeseen affinities. As expected, nested within 'Bigmessidae' are four conventional families as listed above, and relationships among them generally corroborate previous molecular analyses. Our more resolved phylogeny supports a close association of Hydnophora (Merulinidae) with Favites + Montastraea (Faviidae), rather than with the rest of Merulinidae, i.e., Merulina and Scapophyllia. Montastraea annularis, the only Atlantic 'Bigmessidae' is sister to Cyphastrea, a grouping that can be reconciled by their septothecal walls, a microstructural feature of the skeleton determined by recent morphological work. Characters at the subcorallite scale appear to be appropriate synapomorphies for other subclades, which cannot be explained using macromorphology. Indeed, wide geographic sampling here has revealed more instances of possible cryptic taxa confused by evolutionary convergence of gross coral morphology. Conclusions: Numerous examples of cryptic taxa determined in this study support the assertion that diversity estimates of scleractinian corals are erroneous. Fortunately, the recovery of most 'Bigmessidae' genera with only minor degrees of paraphyly offers some hope for impending taxonomic amendments. Subclades are well defined and supported by subcorallite morphological features, providing a robust framework for further systematic work. [ABSTRACT FROM AUTHOR]

Mangrove forests are key tropical marine ecosystems that are rich in fungi, but our understanding of fungal communities associated with mangrove trees and their various organs remains limited because much of the diversity lies within the microbiome. In this study, we investigated the fungal communities associated with the mangrove tree Sonneratia alba throughout Peninsular Malaysia and Singapore. At each sampling location, we collected leaves, fruits, pneumatophores and sediment samples and performed amplicon sequencing of the ribosomal internal transcribed spacer 1 to characterise the associated communities. Results show distinct fungal communities at each sampled location with further differentiation according to the plant part. We find a significant distance decay of similarity, particularly for sediment samples due to the greater variability of sediment environments relative to the more stable fungal habitats provided by living plant organs. We are able to assign taxonomy to the majority of sequences from leaves and fruits, but a much larger portion of the sequences recovered from pneumatophores and sediment samples could not be identified. This pattern underscores the limited mycological research performed in marine environments and demonstrates the need for a concerted research effort on multiple species to fully characterise the coastal microbiome and its role in the functioning of marine ecosystems. [ABSTRACT FROM AUTHOR]

Background: Recent taxonomic revisions of zooxanthellate scleractinian coral taxa have inevitably resulted in confusion regarding the geographic ranges of even the most well-studied species. For example, the recorded distribution ranges of Stylophora pistillata and Pocillopora damicornis, two of the most intensely researched experimental subjects, have been restricted dramatically due to confounding cryptic species. Micromussa is an Indo-Pacific genus that has been revised recently. The revision incorporated five new members and led to substantial range restriction of its type species and only initial member M. amakusensis to Japan and the Coral Triangle. Here, we report the presence of Micromussa amakusensis in Singapore using phylogenetic methods. Results: A total of seven M. amakusensis colonies were recorded via SCUBA surveys at four coral reef sites south of mainland Singapore, including two artificial seawall sites. Colonies were found encrusting on dead coral skeletons or bare rocky substrate between 2 and 5 m in depth. Morphological examination and phylogenetic analyses support the identity of these colonies as M. amakusensis, but the phylogeny reconstruction also shows that they form relatively distinct branches with unexpected lineage diversity. Conclusions: Our results and verified geographic records of M. amakusensis illustrate that, outside the type locality in Japan, the species can also be found widely in the South China Sea. Moreover, our discovery provides a new genus and species record in Singapore and represents the southern-most occurrence of the species in the Indo-Pacific. Despite the extensive survey efforts in Singapore over the last three decades, taxonomic studies integrating morphological and molecular methods remain instrumental in quantifying the actual coral species diversity. [ABSTRACT FROM AUTHOR]