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Bora Bora is a volcanic island in the tropical central South Pacifi c Ocean with a barrier reef and large well developed back-reef lagoons. It forms part of the system of shallow water environments in the archipelagos of French Polynesia that provide stepping stones for the interconnectivity of shallow marine faunas between the tropical Western and Eastern Pacifi c biogeographic regions. The fauna has many similarities to foraminiferal faunas in the south western Indo-Pacifi c but has been demonstrated to be unique. This study provides illustrations and discussions of most of the 184 species of benthic foraminifera identifi ed from sediments in the back-reef lagoon environments at Bora Bora, that span from the shallow immediate back-reef sand banks, to the deep lagoons and to the coastal fringing reefs and embayments around the volcanic island. The illustrated specimens and taxonomic discussions are aimed at providing an identifi cation guide to shallow water tropical benthic foraminifera from the central South Pacifi c region. Six new species have been established, including Textularia boraboraensis, Miliolinella mccullochae, Quinqueloculina guilcheri, Triloculina karimimossadeghae, Coscinospira georgforsteri, and Elphidium venecpeyreae. This study also proposes that the family of cymbaloporetids, Cymbaloporidae, are placed within the Superfamily Discorboidea. [ABSTRACT FROM AUTHOR]

Abstract: Tropical coral reefs are among the most diverse marine ecosystems. In order to better understand temporal and spatial variation in late Quaternary biodiversity, foraminiferal faunas of two fossil, raised reef terraces at the southern Sinai Peninsula were studied and compared to modern coral reef faunas. Eleven U-series dates of shell fragments of the giant clam Tridacna sp. indicates deposition largely during marine isotope stage 5 (MIS 5), 77–129kyr BP, for the two raised terraces. In these terraces, Amphistegina (A. lessonii and A. lobifera) dominates the five fossil foraminiferal associations. The fossil reef-flat association 1 has common Gypsina plana, Homotrema rubra and Acervulina spp., and fossil reef-flat association 2 consists of Amphistegina spp. Of the three fossil fore-reef associations, one has abundant porcelaneous taxa including Sorites, Amphisorus, Peneroplis and Borelis, one has a mix of porcelaneous taxa and attached-arborescent taxa (Homotrema and Placopsilina) and one has abundant attached and arborescent taxa (Miniacina, Gypsina, Acervulina and Planogypsina). The modern fringing reef is dominated by porcelaneous foraminifera, and three modern associations are identified. These include a lagoonal association with abundant Peneroplis pertusus, a reef-flat association dominated by Sorites orbiculus and a fore-reef association with porcelaneous taxa plus common H. rubra, Amphistegina lessonii and A. lobifera. Based on our data and including additional published information on regional biodiversity it appears that during MIS 5 foraminiferal biodiversity was higher and community structure was different than within the modern reefs. These data and regional paleo-climate patterns indicate that oceanographic conditions in the Red Sea were probably closer to normal marine conditions during the last interglacial than they are today. [Copyright &y& Elsevier]

Abstract: Foraminifera from the coral-reef lagoons of two atolls are used to investigate the distribution and diversity of assemblages in the central Indian Ocean. Eight assemblages and 270 species of foraminifera are identified. Three assemblages are reefal and dominated by Amphistegina and Calcarina. Only one lagoon assemblage is present in both atolls, which is characterized by abundant Ammonia sp. 1 and smaller miliolid foraminifera. In Ari Atoll, abundant Amphistegina sp. 1, Operculina ammonoides, Amphistegina radiata and Nummulites venosa characterize one lagoon assemblage and abundant Neoeponides bradyi and Textularia cf. T. cushmani characterize the other. In Rasdhoo Atoll, abundant Textularia gr. foliacea and Spiroloculina nummiformis characterize one lagoon assemblage and abundant Textularia cf. T. cushmani and Textularia sp. 5 characterize the other. The assemblages compare well with sedimentological characteristics, which is also reflected in their distributions. Species diversity in the Maldives appears to be higher than the western Indian Ocean region due to the stronger influence of central Indo-Pacific faunas. It is not however, as high as the central Indo-Pacific region, which may be due to lower habitat diversity. [Copyright &y& Elsevier]

Bora Bora, French Polynesia, represents the classic oceanic (Darwinian) barrier reef system, complete with a deep and extensive lagoon. The foraminiferal faunas of such oceanic barrier reef lagoons have never been studied in detail. How they relate to atoll lagoons and more broadly to coral reef lagoons in general is not known. Back-reef lagoon samples from Bora Bora were studied for their foraminiferal content. The fauna contains sparse larger symbiont bearing foraminifera, and most samples are dominated by a textulariid fauna of mainly Textularia gr. sp. 1 , Textularia gr. foliacea and Textularia oceanica. Statistical analyses revealed three main assemblages, a Textularia- dominated deep central lagoon assemblage, an outer shallow lagoon assemblage characterised by abundant porcelaneous taxa, and a narrow embayment assemblage with abundant Elphidium. Although the species at Bora Bora are common to the Pacific Ocean, the Textularia- dominated assemblages are markedly different from the lagoon assemblages reported from atoll and non-oceanic barrier reef lagoons in the Pacific. These unique assemblages are hypothesised to have evolved due to interactions of the central volcanic island with the lagoon system, likely via the run-off of fine sediment and nutrients. Thereby, the prerequisites for abundant larger, symbiont-bearing foraminifera, which prefer clear, nutrient-poor waters, are largely unavailable. Despite similar substrates and facies, differences between species compositions indicate subtly different disconnected western and eastern deep lagoon environments, possibly due to differences in connectivity to the open ocean. This study provides the first detailed account of the foraminifera from the lagoon of an oceanic barrier reef lagoon. • Oceanic barrier reef lagoons contain a unique foraminiferal assemblage. • First structure and distribution study of a Holocene Textularia -dominated fauna • Textularia -dominated fauna associated with paucity in symbiont bearing taxa. • Volcanic Island and deep oceanic lagoon interactions impact benthic communities. • Different lagoon basin environments elucidated through subtle faunal differences. [ABSTRACT FROM AUTHOR]

Globally, one of the two most common shallow-marine and estuarine foraminiferal genera is Ammonia. Over the past 50 years, the majority of workers have identified specimens in this genus as belonging to just 1-3 cosmopolitan species - A. beccarii, A. tepida and A. parkinsoniana. This has been partly because of the problems of discriminating the Ammonia species based entirely on shell morphology and partly because of a 1974 laboratory study that claimed to have shown that all morphologies were merely ecophenotypic variants of one species - a conclusion that molecular studies have proven to be unequivocally wrong. In this study we recognize, describe and figure sixty-seven living species and infraspecies of Recent Ammonia and two closely-related genera (Acarotrochus, Pseudoeponides) from around the world and summarize their ecological and biogeographic distribution. Twenty-six species and two subspecies are recognized by DNA sequencing and shown to be morphologically distinguishable. A further 39 morphospecies and one subspecies, that have not yet been sequenced, have sufficiently distinct morphology to be recognized. Canonical variates analysis using 42 measured or assessed morphological characters shows that the majority of these species can be readily discriminated by their test morphologies, although a few of the less-ornamented molecular species are verging on being pseudocryptic. Molecular sequencing of the type species of Challengerella (C. bradyi) and Helenina (H. anderseni) places them within our Ammonia clade. Here we continue to recognize the morphologically highly distinct genera Pseudoeponides (subjective senior synonym of Helenina) and allied Acarotrochus. Twenty new species or subspecies are described (molecular T types in brackets): Ammonia abramovichae (T8), A. akitaae, A. aoteana australiensis (T5A), A. arabica (T26), A. ariakensis quiltyi, A. buzasi (T11), A. fajemilai, A. goldsteinae, A. goodayi, A. haigi (T25), A. hattai, A. jorisseni (T23), A. justinparkeri, A. kitazatoi (T10), A. morleyae (T12), A. shchedrinae, A. turgida almogilabinae (T22M), Acarotrochus lippsi, Pseudoeponides hottingeri and P. dubuissoni. Aneotype is designated for A. veneta (Schultze 1854) (T1). We recognize 67 Ammonia and related taxa in this study but speculate that there may be 30 or more additional living species that we are not yet confident to discriminate without molecular sequencing. Ammonia species live in most parts of the world between 62 °N (Faeroe Islands) and 55 °S (Strait of Magellan), where seasonal sea-surface temperatures are 4-10° C and above. One estuarine species (A. veneta, T1) is cosmopolitan, euryhaline and eurythermic. Several species are widespread in one or two ocean regions (e.g., Atlantic and Mediterranean; South Pacific), whereas the majority are endemic to smaller areas (e.g., eastern Mediterranean; Caribbean-Gulf of Mexico). Eleven biogeographic "provinces" are recognized by cluster analysis of presence/absence records with the highest diversities in the Australian and northwest Pacific provinces with 18 and 19 species each). Levels of endemism in our "provinces" range between 0 (temperate Atlantic) and 44% (Australian). [ABSTRACT FROM AUTHOR]

The Trealla Limestone, which forms a veneer of foraminiferal-rich limestone and covers over 4000 km2 of the tectonically stable Southern Carnarvon Platform, contains the oldest evidence for seagrass meadows known in Western Australia. It belongs to Lower Tf1 Letter Stage (based on larger benthic foraminifers) of the Burdigalian, within interval 19–16 Ma, and is the only Miocene unit on the platform. The Trealla Limestone here is coeval to the deeper water lower part of the much thicker Trealla Limestone in the Exmouth Sub-basin to the northwest. A seagrass-meadow depositional environment is indicated by most of the studied microfacies based on comparisons with modern sediment composition and foraminiferal assemblages found in innermost shelf seagrass banks between 23°S and 32°S on the present Western Australian coast. Some levels in the Trealla Limestone on the platform (e.g. with abundant miliolid foraminifers, and absence of coral debris) probably were deposited in and around dense seagrass meadows similar to those present today in the metahaline (40–55 ppt salinity) reaches of Shark Bay; whereas other levels (e.g. coral floatstone) were deposited under normal-marine conditions. Based on comparisons with modern carbonate sediment and biota in the region, the biogenic composition of the Trealla Limestone on the platform suggests winter minimum sea-surface temperatures within the range of 17–22 °C. The Nullabor Limestone in the Eucla Basin, at 10° further south on the southern Australian margin, is similar, at least in part, in composition and age to the Trealla Limestone on the Southern Carnarvon Platform. Both may have been deposited during a Burdigalian sea-level rise, and during part of the Miocene climate optimum recognized elsewhere. Sediment composition and foraminiferal assemblages (including epiphytic types) found in the Trealla and Nullabor limestones are similar to those in the modern seagrass banks of the region. This suggests that seagrasses similar to the extensive Posidonia and Amphibolus stands, which are dominant today between 25°S and 35°S along the Western Australian coast, were widespread during the Burdigalian. • Only Miocene unit on the Southern Carnarvon Platform is thin Trealla Limestone. • Larger benthic foraminifera indicate Burdigalian (19–16 Ma) age. • Seagrass meadow deposition indicated by modern sediment and foraminiferal analogues. • Meadows lived under normal-marine and metahaline salinities as on present coast. • Miocene meadows were similar to present-day Posidonia–Amphibolus stands. [ABSTRACT FROM AUTHOR]