The physiological ecology of the specialist lagoon amphipod, Gammarus insensibilis

Coastal lagoons are habitats of conservation importance. The characteristic fauna of lagoons includes a number of specialist species, some of which are scheduled for protection. Work on the conservation of coastal lagoons has suggested that detailed information on the ecology of lagoon specialist species is essential to ensure management strategies are relevant to the lagoonal species. This study addresses this issue by providing information about the monthly reproductive investment and energy-balance as well as interactions with parasites for the specialist lagoon amphipod, Gammarus insensibilis (Stock). For comparison information is also presented on the reproductive investment of the lagoonal isopod Idotea chelipes (Pallas). Gilkicker lagoon on the south coast of England, UK, from which the majority of samples were taken, demonstrated environmental variability characteristic of coastal lagoons. Annually, temperature varied between 2 and 28 °C and salinity fluctuated between extremes of 24 and 39. The Lymington-Keyhaven lagoons, also on the south coast of England, demonstrated similar variation. This has implications for Gammarus insensibilis, and effects on reproductive investment were evident. The amphipod was shown to employ a continuous reproductive strategy but while the overall investment, expressed as clutch volume, remained relatively stable over the course of the year, the individual components varied. In the summer, when weight-specific embryo number was at its highest with a mean of 13 embryos mg dry wt.-1 the mean size of the individual embryos was small (0.032 mm3). The opposite was true in the winter months, with mean brood sizes as low as 6 embryos mg dry wt.-1 while mean embryo volume was larger, at 0.04 mm3. Idotea chelipes demonstrated a more seasonal reproductive strategy in which winter reproductive output was low. The environmental variability also had effects on the metabolic rates of individual amphipods with temperature related increases in feeding and respiration rates in the summer months. Scope For Growth (SFG), a measure of net energy availability to the organism, was variable during the year and was unrelated to temperature and salinity. Lowest SFG occurred in spring in conjunction with peak reproductive output. This suggested that the amphipods were well adapted to the environmental variation of the lagoon and that it was reproductive investment that represented an important cost to the organism. Eighty four percent of G. insensibilis from Gilkicker were shown to be infected by microphallid trematode parasites. Reproductive investment was negatively affected, with a 36.6 % reduction in weight-specific brood size associated with higher degrees of infection. Respiration rates were also reduced in the infected organisms. The high prevalence of the parasites and the related effects on the host suggest that trematode infection should be considered, alongside the characteristic habitat variability, as an important aspect of the ecology of lagoons

Cp*Fe(Me2PCH2CH2PMe2)(CHO) : hydride shuttle reactivity of a thermally stable formyl complex.

[Cp*Fe(Me2PCH2CH2PMe2)(CO)]+ [BArF24]− has been synthesised and characterised using single crystal X-ray diffraction, NMR and IR spectroscopies. Reduction of the CO ligand using Na[Et3BH] produces the corresponding neutral formyl complex Cp*Fe(Me2PCH2CH2PMe2)(CHO), that is very thermally stable, and which is attributed to the electron-releasing properties of the spectator ligands. This compound is a potent hydride donor which exists in equilibrium with [Et3BH]−, Et3B, and the structural isomer (η4-C5Me5H)Cp*Fe(Me2PCH2CH2PMe2)(CO), resulting from reversible hydride migration to the Cp* ligand

New reactivity at the silicon bridge in sila[1]ferrocenophanes

Two new types of reactivity involving silicon-bridged [1]ferrocenophanes are described.</p

Main-chain metallopolymers at the static–dynamic boundary based on nickelocene

Interactions between metal ions and ligands in metal-containing polymers involve two bonding extremes: persistent covalent bonding, in which the polymers are essentially static in nature, or labile coordination bonding, which leads to dynamic supramolecular materials. Main-chain polymetallocenes based on ferrocene and cobaltocene fall into the former category because of the presence of strong metal–cyclopentadienyl bonds. Herein, we describe a main-chain polynickelocene—formed by ring-opening polymerization of a moderately strained [3]nickelocenophane monomer—that can be switched between static and dynamic states because of the relatively weak nickel–cyclopentadienyl ligand interactions. This is illustrated by the observation that, at a low concentration or at an elevated temperature in a coordinating or polar solvent, depolymerization of the polynickelocene occurs. A study of this dynamic polymer–monomer equilibrium by 1H NMR spectroscopy allowed the determination of the associated thermodynamic parameters. Microrheology data, however, indicated that under similar conditions the polynickelocene is considered to be static on the shorter rheological timescale

New Horned Dinosaurs from Utah Provide Evidence for Intracontinental Dinosaur Endemism

Background:\ud During much of the Late Cretaceous, a shallow, epeiric sea divided North America into eastern and western landmasses. The western landmass, known as Laramidia, although diminutive in size, witnessed a major evolutionary radiation of dinosaurs. Other than hadrosaurs (duck-billed dinosaurs), the most common dinosaurs were ceratopsids (large-bodied horned dinosaurs), currently known only from Laramidia and Asia. Remarkably, previous studies have postulated the occurrence of latitudinally arrayed dinosaur “provinces,” or “biomes,” on Laramidia. Yet this hypothesis has been challenged on multiple fronts and has remained poorly tested.\ud \ud Methodology/Principal Findings:\ud Here we describe two new, co-occurring ceratopsids from the Upper Cretaceous Kaiparowits Formation of Utah that provide the strongest support to date for the dinosaur provincialism hypothesis. Both pertain to the clade of ceratopsids known as Chasmosaurinae, dramatically increasing representation of this group from the southern portion of the Western Interior Basin of North America. Utahceratops gettyi gen. et sp. nov.—characterized by short, rounded, laterally projecting supraorbital horncores and an elongate frill with a deep median embayment—is recovered as the sister taxon to Pentaceratops sternbergii from the late Campanian of New Mexico. Kosmoceratops richardsoni gen. et sp. nov.—characterized by elongate, laterally projecting supraorbital horncores and a short, broad frill adorned with ten well developed hooks—has the most ornate skull of any known dinosaur and is closely allied to Chasmosaurus irvinensis from the late Campanian of Alberta.\ud \ud Conclusions/Significance:\ud Considered in unison, the phylogenetic, stratigraphic, and biogeographic evidence documents distinct, co-occurring chasmosaurine taxa north and south on the diminutive landmass of Laramidia. The famous Triceratops and all other, more nested chasmosaurines are postulated as descendants of forms previously restricted to the southern portion of Laramidia. Results further suggest the presence of latitudinally arrayed evolutionary centers of endemism within chasmosaurine ceratopsids during the late Campanian, the first documented occurrence of intracontinental endemism within dinosaurs

Cranial Growth and Variation in Edmontosaurs (Dinosauria: Hadrosauridae): Implications for Latest Cretaceous Megaherbivore Diversity in North America

The well-sampled Late Cretaceous fossil record of North America remains the only high-resolution dataset for evaluating patterns of dinosaur diversity leading up to the terminal Cretaceous extinction event. Hadrosaurine hadrosaurids (Dinosauria: Ornithopoda) closely related to Edmontosaurus are among the most common megaherbivores in latest Campanian and Maastrichtian deposits of western North America. However, interpretations of edmontosaur species richness and biostratigraphy have been in constant flux for almost three decades, although the clade is generally thought to have undergone a radiation in the late Maastrichtian. We address the issue of edmontosaur diversity for the first time using rigorous morphometric analyses of virtually all known complete edmontosaur skulls. Results suggest only two valid species, Edmontosaurus regalis from the late Campanian, and E. annectens from the late Maastrichtian, with previously named taxa, including the controversial Anatotitan copei, erected on hypothesized transitional morphologies associated with ontogenetic size increase and allometric growth. A revision of North American hadrosaurid taxa suggests a decrease in both hadrosaurid diversity and disparity from the early to late Maastrichtian, a pattern likely also present in ceratopsid dinosaurs. A decline in the disparity of dominant megaherbivores in the latest Maastrichtian interval supports the hypothesis that dinosaur diversity decreased immediately preceding the end Cretaceous extinction event

The Seventh Data Release of the Sloan Digital Sky Survey

This paper describes the Seventh Data Release of the Sloan Digital Sky Survey (SDSS), marking the completion of the original goals of the SDSS and the end of the phase known as SDSS-II. It includes 11663 deg^2 of imaging data, with most of the roughly 2000 deg^2 increment over the previous data release lying in regions of low Galactic latitude. The catalog contains five-band photometry for 357 million distinct objects. The survey also includes repeat photometry over 250 deg^2 along the Celestial Equator in the Southern Galactic Cap. A coaddition of these data goes roughly two magnitudes fainter than the main survey. The spectroscopy is now complete over a contiguous area of 7500 deg^2 in the Northern Galactic Cap, closing the gap that was present in previous data releases. There are over 1.6 million spectra in total, including 930,000 galaxies, 120,000 quasars, and 460,000 stars. The data release includes improved stellar photometry at low Galactic latitude. The astrometry has all been recalibrated with the second version of the USNO CCD Astrograph Catalog (UCAC-2), reducing the rms statistical errors at the bright end to 45 milli-arcseconds per coordinate. A systematic error in bright galaxy photometr is less severe than previously reported for the majority of galaxies. Finally, we describe a series of improvements to the spectroscopic reductions, including better flat-fielding and improved wavelength calibration at the blue end, better processing of objects with extremely strong narrow emission lines, and an improved determination of stellar metallicities. (Abridged)Comment: 20 pages, 10 embedded figures. Accepted to ApJS after minor correction

Herbivory, Connectivity, and Ecosystem Resilience: Response of a Coral Reef to a Large-Scale Perturbation

Coral reefs world-wide are threatened by escalating local and global impacts, and some impacted reefs have shifted from coral dominance to a state dominated by macroalgae. Therefore, there is a growing need to understand the processes that affect the capacity of these ecosystems to return to coral dominance following disturbances, including those that prevent the establishment of persistent stands of macroalgae. Unlike many reefs in the Caribbean, over the last several decades, reefs around the Indo-Pacific island of Moorea, French Polynesia have consistently returned to coral dominance following major perturbations without shifting to a macroalgae-dominated state. Here, we present evidence of a rapid increase in populations of herbivorous fishes following the most recent perturbation, and show that grazing by these herbivores has prevented the establishment of macroalgae following near complete loss of coral on offshore reefs. Importantly, we found the positive response of herbivorous fishes to increased benthic primary productivity associated with coral loss was driven largely by parrotfishes that initially recruit to stable nursery habitat within the lagoons before moving to offshore reefs later in life. These results underscore the importance of connectivity between the lagoon and offshore reefs for preventing the establishment of macroalgae following disturbances, and indicate that protecting nearshore nursery habitat of herbivorous fishes is critical for maintaining reef resilience

The status of the world's land and marine mammals: diversity, threat, and knowledge

Knowledge of mammalian diversity is still surprisingly disparate, both regionally and taxonomically. Here, we present a comprehensive assessment of the conservation status and distribution of the world's mammals. Data, compiled by 1700+ experts, cover all 5487 species, including marine mammals. Global macroecological patterns are very different for land and marine species but suggest common mechanisms driving diversity and endemism across systems. Compared with land species, threat levels are higher among marine mammals, driven by different processes (accidental mortality and pollution, rather than habitat loss), and are spatially distinct (peaking in northern oceans, rather than in Southeast Asia). Marine mammals are also disproportionately poorly known. These data are made freely available to support further scientific developments and conservation action

A blueprint for an inclusive, global deep-sea Ocean Decade field programme

The ocean plays a crucial role in the functioning of the Earth System and in the provision of vital goods and services. The United Nations (UN) declared 2021–2030 as the UN Decade of Ocean Science for Sustainable Development. The Roadmap for the Ocean Decade aims to achieve six critical societal outcomes (SOs) by 2030, through the pursuit of four objectives (Os). It specifically recognizes the scarcity of biological data for deep-sea biomes, and challenges the global scientific community to conduct research to advance understanding of deep-sea ecosystems to inform sustainable management. In this paper, we map four key scientific questions identified by the academic community to the Ocean Decade SOs: (i) What is the diversity of life in the deep ocean? (ii) How are populations and habitats connected? (iii) What is the role of living organisms in ecosystem function and service provision? and (iv) How do species, communities, and ecosystems respond to disturbance? We then consider the design of a global-scale program to address these questions by reviewing key drivers of ecological pattern and process. We recommend using the following criteria to stratify a global survey design: biogeographic region, depth, horizontal distance, substrate type, high and low climate hazard, fished/unfished, near/far from sources of pollution, licensed/protected from industry activities. We consider both spatial and temporal surveys, and emphasize new biological data collection that prioritizes southern and polar latitudes, deeper (&gt; 2000 m) depths, and midwater environments. We provide guidance on observational, experimental, and monitoring needs for different benthic and pelagic ecosystems. We then review recent efforts to standardize biological data and specimen collection and archiving, making “sampling design to knowledge application” recommendations in the context of a new global program. We also review and comment on needs, and recommend actions, to develop capacity in deep-sea research; and the role of inclusivity - from accessing indigenous and local knowledge to the sharing of technologies - as part of such a global program. We discuss the concept of a new global deep-sea biological research program ‘Challenger 150,’ highlighting what it could deliver for the Ocean Decade and UN Sustainable Development Goal 14