Reophax bruneiensis n. sp. From the shallow-water environment of Brunei Darussalam

Anew species of Reophax is documented from the shallow marine settings offshore Brunei Darussalam. The new taxon differs from other recent species of Reophax by its selective agglutination consisting mainly of tests of megalospheric specimens of Amphistegina. Reophax bruneiensis n.sp. differs from other known species in having a selectively agglutinated wall, few numbers of chambers increasing rapidly in size, and a terminal aperture not supported by any neck. This new species possibly acts as detritivore within the bottom sediments characterized by differentiated calcareous bioclasts and clay-sized siliciclasts derived by the river supply

Sedimentological characterisation of sea bottom samples collected offshore Muara and Tutong, Brunei Darussalam

The study aims to get some additional knowledge on the modern seafloor composition offshore Brunei Darussalam by looking at the recent stratigraphic succession of the deposited sediments and their distribution patterns. For this reason, 10 shallow cores (22 to 46 cm thick) have been collected by scuba diving along two depth transects spanning from water depth of 20 to 60 m. One of the transects has been sampled north-northwest of the Muara village, just in front of the Brunei Bay and the other one off the coast near Tutong town, away from major sedimentary inputs. The results obtained portray two different sea bottom compositions and two different depth-related sediment distributions. The Muara transect is highly rich in mud and yielded abundant biogenic component at all investigated depths. The Tutong transect has a higher sand content but display constant changes along with depth. The sediment is mostly composed by biogenic grains such as rests of sponges, foraminifera, molluscs and echinoderms; the not biogenic grains are for the vast majority made of quartz. The sandy fractions of both transects have been tested for cyclicity and all cores can be described by functions with comparable periods, thus indicating that an oscillatory environmental event such as the alternation of the monsoon seasons, has similar influence on the seafloor of both transects

Tracing migration of larger benthic foraminifera across atolls in the South China Sea

The distribution of modern benthic foraminifera is studied from offshore reefs of Brunei Darussalam located in northwest Borneo with enhanced siliclastic influence, and from Louisa Reef, an atoll in the Southern Spratly Islands under fully carbonatic environment. The main families of larger benthic foraminifera found from offshore reefs of Brunei are the Calcarinidae, Amphisteginidae and the Operculinidae, while at the Louisa Reef are the Calcarinidae, Amphisteginidae and the Soritidae. Larger benthic foraminifera are mainly concentrated in the tropical regions and in shallow waters, and their distribution depends on important environmental factors such as water depth, sunlight and type of sediment. Migration of LBF has been recorded since the Paleogene from the Americas to Africa and the Mediterranean Sea, and later to the Indo-Pacific where the modern biodiversity hotspot occurs. Hence looking into any possible migration throughout certain groups of LBF could help in understanding their biogeographic distribution through time within the Indo-Pacific region. Along the atolls in South China Sea the marine environments meet their living preferences, hence tracing their presence, distributions, and abundances could shed further light on their regional migration pattern

Palynology of miocene sediments in brunei darussalam: First SEM investigations of pollen and spores, and their taxonomy and palaeoenvironmental interpretation

Brunei Darussalam\u2019s geology is characterized by extensive Neogene fluvio-deltaic to shallow marine siliciclastic deposits, which have been studied here to highlight their palynological content. So far, there are only few reports that investigate fossil pollen and only one focuses on detailed taxonomical description using light microscopy (LM). The rest are studies on a wider regional scale in northwest Borneo sometimes including Brunei but without much emphasizes on taxonomy. To investigate pollen thoroughly, the use of scanning electron microscopy (SEM) is important, as this can provide valuable information on the sculptures of the pollen grains which with LM alone cannot be observed. Our study here provides LM images alongside the first SEM images of pollen and spores from Miocene sediments in Brunei Darussalam. The results point to a moderate-diverse flora comprising 37 families and 62 pollen and spore taxa. Most common ones are mangrove types which are Rhizophoraceae and Lythraceae taxa. The families of Combretaceae, Malvaceae, and other less common pollen groups are typical of tropical floral elements. The recovered families of Anacardiaceae, Arecaceae (five taxa), Calophyllaceae, Dilleniaceae, Dipterocarpaceae (two taxa), Elaeocarpaceae, Euphorbiaceae (four taxa), Phyllanthaceae (two taxa), Podocarpaceae, Proteaceae, Rubiaceae, Sapindaceae and Sapotaceae indicate mixed Dipterocarpaceae forests ranging from hinterland to peat swamp areas