Diversity and Distribution of Microbial Communities Associated with Reef Corals of the Malay Peninsula.

Coral-associated bacteria play critical roles in the regulation of coral health and function. Environmental perturbations that alter the bacterial community structure can render the coral holobiont more susceptible and less resilient to disease. Understanding the natural variation of the coral microbiome across space and host species provides a baseline that can be used to distinguish shifts in community structure. Using a 16S rRNA gene metabarcoding approach, this study examines bacterial community structure across three scleractinian coral hosts. Our results show that corals of three regions-eastern and western Peninsular Malaysia and Singapore-host distinct bacterial communities; despite these differences, we were able to identify a core microbiome shared across all three species. This core microbiome was also present in samples previously collected in Thailand, suggesting that these core microbes play an important role in promoting and maintaining host health. For example, several have been identified as dimethylsulfoniopropionate (DMSP) metabolizers that have roles in sulfur cycling and the suppression of bacterial pathogens. Pachyseris speciosa has the most variable microbiome, followed by Porites lutea, with the composition of the Diploastrea heliopora microbiome the least variable throughout all locations. Microbial taxa associated with each region or site are likely shaped by local environmental conditions. Taken together, host identity is a major driver of differences in microbial community structure, while environmental heterogeneity shapes communities at finer scales.

Updated checklist of polychaete species (Annelida) recorded from Malaysia, with remarks on the research history.

Background: An updated comprehensive checklist of polychaete species, which have been recorded from Malaysian waters, is provided, with their geographic distributions and the research history for them. A total of 57 species belonging to 30 families have been reported since the early 1870s, with Nereididae as the most dominant family with ten species; however, more than half of the total are questionable species in the country. Despite the increased efforts of polychaete studies in the past decade, the taxonomic endeavour of discovering and describing species in the country could be higher. Malaysian polychaetes were mostly recorded from Peninsular Malaysia, whereas very few were from Borneo Island. Most previously recorded species were associated with intertidal and estuarine habitats and a few were found in the subtidal and freshwater environments. We stress the need for urgent research on this biologically, ecologically and culturally relevant taxonomic group as the species accumulation curve grows exponentially in this megadiverse country. New information: The current checklist has been updated since the previous one in 2013. Many species previously listed were judged as doubtful and not taxonomically reliable.

DNA barcoding of shrimps from a mangrove biodiversity hotspot.

A total of 74 shrimp specimens were sequenced at a 584 bp segment of the cytochrome oxidase subunit I (COI) gene to examine patterns of DNA barcode variation in a mangrove biodiversity hotspot. The Maximum Likelihood tree, barcode gap analysis, Automatic Barcode Gap Discovery analysis and sequence comparisons with data available from Barcode of Life Data System and GenBank recovered 18 taxa of which 15 were identified to species level, 2 at genus level and a single taxon at order level. Two deep mitochondrial DNA lineage divergences were found in the giant tiger prawn, Penaeus monodon. It is suggested that one of the lineages is a consequence of an introduction from aquaculture activity. These results have provided a reliable barcode library for cataloguing shrimps in this area.