Molecular oxygen (O(2)) began to accumulate in the atmosphere and surface ocean ca. 2,400 million years ago (Ma), but the persistent oxygenation of water masses throughout the oceans developed much later, perhaps beginning as recently as 580-550 Ma. For much of the intervening interval, moderately oxic surface waters lay above an oxygen minimum zone (OMZ) that tended toward euxinia (anoxic and ...

Before the Earth's complete oxygenation (0.58 to 0.55 billion years [Ga] ago), the photic zone of the Proterozoic oceans was probably redox stratified, with a slightly aerobic, nutrient-limited upper layer above a light-limited layer that tended toward euxinia. In such oceans, cyanobacteria capable of both oxygenic and sulfide-driven anoxygenic photosynthesis played a fundamental role in the gl...

A new species of leucothoid amphipod, Leucothoe eltoni sp. n., is described from coral reefs in Raja Ampat, Indonesia where it inhabits the branchial chambers of solitary tunicates. With an inflated first gnathopod superficially resembling the genus Paraleucothoe, this new species has a two-articulate maxilla 1 palp characteristic of the genus Leucothoe. While described from coral reef environm...

Little is known about pyrethroid fate and effects in estuarine and marine environments. In the present study, the extent and magnitude of pyrethroids in coastal embayments of the Southern California Bight (SCB), USA, were assessed. Using a stratified probabilistic design, 155 sediment samples were collected from four embayment habitats (estuaries, marinas, open bays, and ports) and analyzed for...

The eusirid genus Rhachotropis S.I. Smith, 1883 has a worldwide distribution and the largest bathymetric range known from any amphipod genus. A large, charismatic, colourful species was collected below 800 m at two sites 1000 km apart on the southern Kermadec Ridge and on the Chatham Rise in the south-western Pacific off eastern New Zealand. The new species, Rhachotropis oweni is described, inc...

Three new species of the subterranean amphipod of the genus Pseudocrangonyx: P. tiunovi sp. nov., P. holsingeri sp. nov., P. sympatricus sp. nov. and male specimen for P. kseniae Sidorov, 2012 from the South Primory, Far East of Russia are described. The species were found in springs and related groundwater habitats of several river systems belonging to the Japan Sea basin. Phylogenetic analysi...

Numerous specimens of poorly known pleustid amphipod Pleusymtes japonica (Gurjanova, 1938) (Crustacea: Amphipoda: Pleustidae: Pleusymtinae) were found in association with large hermit crab Pagurus ochotensis Brandt, 1851 (Crustacea: Decapoda: Paguridae) near Furugelma Island in the Sea of Japan. This is the first report of the species in association with hermit crabs. Amphipods were found livin...