Depth limit for reef building corals in the Au’au Channel, S.E. Hawaii

In this paper, the relationship between reef building (accretion) and depth in an optimal inter-island channel environment in Hawaii is analyzed. For accretion, the growth rate of Porites lobata is used as a proxy for the reef community, because it is the most abundant and dominant species of reef building coral in Hawaii. Optimal growth of P. lobata occurs at a depth of 6 m, below which both growth rate and abundance decrease with increasing depth. A lower depth limit for this species is found at about 80–100 m, yet reef accretion ceases at ~50 m depth. Below 50 m, rates of bio-erosion of colony holdfasts equal or exceed the growth of basal attachments, causing colonies to detach from the bottom. Continued bio-erosion further erodes and dislodges colonies leading to their breakdown and ultimately to the formation of coralline rubble and sand. Thus, within this channel environment in Hawaii, a threshold for reef building exists at ~ 50 m depth, where coral accretion is interrupted by bio-erosion. Conceptually viewed, this depth horizon is analogous to a vertical Darwin Point, although quite narrow in space and time. More importantly, it explains the history of reef morphology in the Au’au Channel where a chronological hiatus exists at a depth near 50 m. This hiatus separates shallower modern growth (about 100 years or less) from the deeper reef which is all due to accretion during the early Holocene or Pleistocene epochs.     

Coral reef monitoring in the Iles Eparses,Mozambique Channel (2011–2013)

Monitoring of coral reefs has become a major tool for understanding how they are changing, and for managing them in a context of increasing degradation of coastal ecosystems. The Global Coral Reef Monitoring Network (GCRMN) has near-global coverage, but there are few remote sites free of direct human impact that can serve as reference sites. This study provides baseline data for the French Iles Eparses in the Mozambique Channel, Western Indian Ocean (WIO), whose coral reefs are little known owing to their limited accessibility, and have been free from fishing pressure for over 20 years. Surveys of coral reef health and fish community structure were undertaken at four of the islands (Europa, Bassas da India, Juan de Nova and Glorieuses) in 2011–2013. Monitoring was conducted using standardized GCRMN methods for benthos and fish communities, at the highest taxonomic level. Benthic cover showed a latitudinal gradient, with higher coral cover and conversely lower algae cover (60% and 14% respectively) in the south of the Mozambique Channel. This could be due to the geomorphology of the islands, the latitudinal temperature gradient, and/or the history of chronic stress and bleaching events during the last decades. Fish also showed a latitudinal gradient with higher diversity in the north, in a center of diversity for the western Indian Ocean already recognized for corals. An exceptional biomass fish was recorded (approximately 3500 kg/ha excluding sharks, compared to a maximum of 1400 kg/ha elsewhere in the WIO). The presence of large predators and sharks in all the islands as well as the absence of fleshy benthic algae were indicators of the good health of the reef systems. Nevertheless, these islands are beginning to experience illegal fishing, particularly in the north of the Mozambique Channel, demonstrating their vulnerability to exploitation and the need to protect them as reference sites for coral reef studies, including of climate change impacts, for the region and globally.     

Do predatory fishes affect the structure of an epiphytal amphipod assemblage on a protected algal reef in Hawaii?

On a sheltered Hawaiian algal reef seaweeds are abundant and large herbivorous fishes are absent. Epiphytal amphipods are abundant on their seaweed habitats. Predator exclusion experiments were conducted to determine if predatory fishes affect the abundance, diversity, and size distribution of the epiphytal amphipod community living on plant substrata. Results suggested that amphipod abundance, expected number of species, and size distribution were all independent of predation pressure.     

Changes in the species composition of benthic macroalgal communities of the upper subtidal zone on a coral reef in Sanya Bay (Hainan Island, China) during 2009–2012

Investigations of macroalgae were carried out on a coral reef at the Luhuitou Peninsula in Sanya Bay (Hainan Island, China) in the upper subtidal zone at a depth of 0.5 to 4 m during the dry season (in April 2009 and 2012). In total, 130 species, varieties, and forms of marine macroalgae were found: 71 (54%) Rhodophyta, 33 (25%) Chlorophyta, and 26 (21%) Phaeophyceae. In terms of the number of species and the floristic composition of algae in the communities, the reef benthic flora in the subtidal zone of Sanya Bay, which is polluted by municipal waste waters and aquaculture wastes, was close to the flora of Indo-Pacific coral reefs situated in areas with low pollution. In 2009 and 2012, the algal turf communities differed both in the algal species diversity and in the composition of dominant species. These differences might be due to an annual periodicity of changes in vegetation: algal turf patches are detached from the hard substrate and a new algal community is formed at this location.     

Vertical Distribution of Pelagic Ostracods (Ostracoda,Halocyprinidae) in the Australian–New Zealand Sector of the Southern Ocean

Samples of plankton from the Australian–New Zealand sector of the Southern Ocean have been examined. A species list of pelagic fauna of ostracods is presented including latitudes and depths for Antarctic and Subantarctic water structures and the neighboring subtropical regions. The vertical distribution of ostracods is studied in the waters of the Subantarctic and Antarctic.     

Effects of the 1997–1998 El Niño on the cnidarian community of a high turbidity coral reef system (northern Bahia,Brazil)

We are reporting on the results of a 4-year study that allowed for the analysis of the effects of the 1997–1998 El Niño Southern Oscillation (ENSO) event on the cnidarian community of the naturally high-turbidity reefs of northern Bahia, Brazil. Cnidarian densities were significantly different between pre- and post-ENSO years, with significant consequent changes in community composition. BIOENV analysis identified variations in turbidity, mean temperature variance, and cloud cover as the factors best explaining changes in the community. We suggest that the 1997–1998 ENSO event, the most intense on record, had a differential effect on the cnidarian community. Highest mortalities were suffered by minute hydroid colonies, partial mortality by octocorals and actiniarians, while large hydroid colonies and scleractinians were the least affected. Such an ability to survive under the stressful environmental regime imposed by this ENSO event is attributed to the presence of morphological pre-adaptations (e.g., size of colony polyps, abundance of certain nematocyst types) and the inherent phenotypic plasticity that results from long-term exposure to naturally stressful conditions.     

The influence of solar radiation on bleaching of shallow water reef corals in the Andaman Sea, 1993–1998

Historically, elevated sea-temperature excursions have been used almost exclusively to explain incidences of natural coral bleaching. Little attention, however, has been paid to instances where environmental conditions appear conducive to bleaching but none has been observed. In this paper we examine contemporaneous records of sea temperature and solar radiation (photosynthetically active radiation; PAR, 400-700 nm) over a 6-year period at a site in the Andaman Sea where regular monitoring of shallow water reef coral communities has been conducted since 1979. Four years (1991, 1995, 1997, and 1998) when anomalous sea temperatures were recorded in May are compared. We suggest a complex interaction of PAR and sea temperature, whereby elevated solar radiation prior to sea-temperature maxima may actually protect corals against subsequent bleaching. In addition, we demonstrate the important role that sea-level anomalies play in modifying the underwater light regime to bring about such conditions.     

Vertical variability of primary production and chlorophyll a in the Drake Passage during the austral spring period (October–November)

Vertical distribution of primary production (PP) and concentration of chlorophyll a (Chl) were studied during two cruises in the Drake Passage in November 2007 and 2008. Variability in the vertical curves of Chl was registered in the different hydrological zones of the Drake Passage. The Antarctic waters were characterized by a well-defined deep Chl maximum (DCM) during the austral spring. The investigation allowed us to conclude that the influence of DCM should be taken into consideration for a model-based estimation of annual PP in the Southern Ocean.     

Impacts of the exotic,nitrogen-fixing black locust (Robinia pseudoacacia) on nitrogen-cycling in a pine–oak ecosystem

We investigated the influence of the exotic nitrogen-fixing black locust (Robinia pseudoacacia) on nitrogen cycling in a pitch pine (Pinus rigida) −scrub oak (Quercus ilicifolia, Q. prinoides) ecosystem. Within paired pine-oak and adjacent black locust stands that were the result of a 20-35 year-old invasion, we evaluated soil nutrient contents, soil nitrogen transformation rates, and annual litterfall biomass and nitrogen concentrations. In the A horizon, black locust soils had 1.3-3.2 times greater nitrogen concentration relative to soils within pine-oak stands. Black locust soils also had elevated levels of P and Ca, net nitrification rates and total net N-mineralization rates. Net nitrification rates were 25-120 times greater in black locust than in pine-oak stands. Elevated net N-mineralization rates in black locust stands were associated with an abundance of high nitrogen, low lignin leaf litter, with 86 kg N ha^–1 yr^–1 in leaf litter returned compared with 19 kg N ha^–1 yr^–1 in pine-oak stands. This difference resulted from a two-fold greater litterfall mass combined with increased litter nitrogen concentration in black locust stands (1.1% and 2.6% N for scrub oak and black locust litter, respectively). Thus, black locust supplements soil nitrogen pools, increases nitrogen return in litterfall, and enhances soil nitrogen mineralization rates when it invades nutrient poor, pine-oak ecosystems. This revised version was published online in June 2006 with corrections to the Cover Date.     

Factors affecting fish diversity on a temperate reef: the fish assemblage of Palos Verdes Point, 1974–1981

Synopsis We conducted underwater fish assemblage surveys, benthic quinaldine sampling, and ichthyoplankton collections over high and low relief reefs at Palos Verdes Point, California from 1974 through 1981. Seventy-three species (adults and larvae) were collected or observed at Palos Verdes. Of the 24 most abundant species, 8 showed significant abundance trends correlated with changes in sea surface temperatures; four increasing, and four decreasing. Two taxa occurred predominantly in the kelp canopy, while seven others were distributed at least 20% of the time between the canopy and the bottom. There was little significant change in the Palos Verdes benthic fish assemblage with development of the kelp bed. Only the kelp bass, Paralabrax clathratus, showed a significant increase in abundance that correlated with the kelp bed formation. Similarly, we did not note an increase in juvenile fish during this period. In general, we suggest that the presence or absence of kelp has little effect on the abundance of most fish species in a high relief environment. Analysis of our data and that of other studies indicate that kelp bed fish assemblages within the Southern California Bight vary in a south-north direction. The Palos Verdes Point kelp bed appears to be more productive than those nearer the limit of the Bight, but was consistently lower in both fish abundance and diversity then the nearby breakwater at King Harbor. This difference has been maintained even though changes in the species structure at King Harbor has altered sufficiently since 1976 for the two formerly distinct assemblages to be significantly concordant.     

Spinicaudata (“Conchostraca,” Crustacea) from the Middle Keuper (Upper Triassic) of the southern Germanic Basin,with a review of Carnian–Norian taxa and suggested biozones

The Coburg Sandstone member of the Hassberge Formation, Middle Keuper, Carnian, Upper Triassic, in the Germanic Basin of Central Europe contains spinicaudatan branchiopods which considerably broaden the known spectrum and provide important data on the phylogenetic history and intercontinental correlation of this systematic group. The spinicaudatan fauna for this lithostratigraphic unit is described in detail and includes Euestheria kozuri sp. nov., E.? sp. nov. A, Gregoriusella striatula sp. nov., Laxitextella freybergi Kelber and Kozur in Kozur and Weems, 2007, L. dorsorecta (Reible, 1962), and Laxitextella? sp. A. Additional discussions deal with Euestheria multicostata (Geyer, 1987), E. winterpockensis (Bock, 1953a), Laxitextella laxitexta (Sandberger in Jones, 1890), Laxitextella multireticulata (Reible, 1962), and “Laxitextella? hausmanni (Schmidt, 1938),” as well as problems with (sub)global zonations that are based on spinicaudatans and suggested to be of Carnian and Norian age.     

The life – history of the peach silver mite,Aculus fockeui (Acari: Eriophyidae) in Egypt

The peach silver mite Aculus fockeui (Nalepa and Trouessart) successfully developed from egg to adult stage when reared on a nectarine or peach leaflet attached with soft lateral divided branch dipped in test tube at different constant temperatures and 70% r.h. The effect of temperature on the development, reproduction and population growth was investigated. Below 20°C all activity ceased and by 33°C the adult began to slow down and cease all activity. At least of 34% of the generation time was spent in the egg stage at 29°C. Adult longevity decreased with increasing temperature. Fecundity was highest at 29°C with 43.16 eggs per female. Life table parameters showed that the population of A. fockeui on nectarine leaves multiplied 30.04 times in a generation time of 18.49 days at 29°C, while the population on peach leaves increased 13.87 times in a generation time of 19.18 days under the same conditions.     

Palaeoenvironmental analysis of scleractinian reef corals from the Oligo–Miocene Qom Formation in the Vartun section (northeastern Esfahan,central Iran)

This paper presents a review of palaeoenvironmental reconstructions of scleractinian corals from the Oligo–Miocene Qom Formation in northeastern Esfahan, central Iran. A total of nine genera and four species of colonial corals are identified, including Platycoenia iranica, Goniopora sp., Porites sp., Tarbellastraea reussiana, Solenastrea sp., Favites neglecta, Leptoria sp., Hydnophora cf. pulchra, Hydnophora sp., and Madracis (?) sp. These corals, all parts of massive colonies, are indicative of a reefal environment, with the main constituents, including Leptoria and Hydnophora, possessing massive meandroid, massive hydnophoroid and massive mushroom- to dome-shaped hydnophoroid colonies. The corals identified here are generally indicative of the upper photic zone and shallow water depths of less than 20 m. In the reefal environment, these corals built a wave-resistant and rigid carbonate framework in the form of a reef-front zone encapsulated by environmental conditions including low sedimentation rates and high wave energy. The occurrence of Goniopora and Porites with distinct calicles reflects clearer waters in the external part of the reefal environment.     

Oribatid mites (Acari,Oribatida) from the Oumé region (Côte d’Ivoire): list of taxa,new findings,description of a new species

The present study is based on oribatid mite material (Acari, Oribatida) collected from the Oumé region (Côte d’Ivoire, West Africa) in 2007. A list of identified taxa, including 67 species from 50 genera and 31 families, is presented; all species, genera and families are registered in this country for the first time; Kalloia simpliseta, Scheloribates latoincisus and Pergalumna paraelongata are recorded in the Ethiopian region for the first time. One new species of the genus Arcoppia (Oppiidae) is described; A. goulikaoensis Ermilov sp. n. differs from A. robusta Mahunka, 1988 by the well-developed bothridial heads (versus not developed), barbed branches on the bothridial setae (versus smooth) and smooth notogaster surface (versus lineolate).     

Observations on the biology of Leuciscus ‘svallize’ in the Kremasta reservoir (Greece)

The age, growth, feeding habits and reproductive biology of Leuciscus svallize in artificial lake Kremasta (Greece), are described. There is a considerable similarity in the feeding and reproductive characteristics between L. svallize and L. cephalus and also a similarity in the life span, growth patterns and age of maturation between L. svallize and some southern L. cephalus populations, which may suggest similar responses of closely related taxa to similar conditions.     

Effects of a lipid environment on the fibrillogenic pathway of the N-terminal polypeptide of human apolipoprotein A-I, responsible for in vivo amyloid fibril formation

In amyloidosis associated with apolipoprotein A-I (ApoA-I), heart amyloid deposits are mainly constituted by the 93-residue ApoA-I N-terminal region. A recombinant form of the amyloidogenic polypeptide, named [1-93]ApoA-I, shares conformational properties and aggregation propensity with its natural counterpart. The polypeptide, predominantly in a random coil state at pH 8.0, following acidification to pH 4.0 adopts a helical/molten globule transient state, which leads to formation of aggregates. Here we provide evidence that fibrillogenesis occurs also in physiologic-like conditions. At pH 6.4, [1-93]ApoA-I was found to assume predominantly an α-helical state, which undergoes aggregation at 37°C over time at a lower rate than at pH 4.0. After 7 days at pH 6.4, protofibrils were observed by atomic force microscopy (AFM). Using a multidisciplinary approach, including circular dichroism (CD), fluorescence, electrophoretic, and AFM analyses, we investigated the effects of a lipid environment on the conformational state and aggregation propensity of [1-93]ApoA-I. Following addition of the lipid-mimicking detergent Triton X-100, the polypeptide was found to be in a helical state at both pH 8.0 and 6.4, with no conformational transition occurring upon acidification. These helical conformers are stable and do not generate aggregated species, as observed by AFM after 21 days. Similarly, analyses of the effects of cholesterol demonstrated that this natural ApoA-I ligand induces formation of α-helix at physiological concentrations at both pH 8.0 and 6.4. Zwitterionic, positively charged, and negatively charged liposomes were found to affect [1-93]ApoA-I conformation, inducing helical species. Our data support the idea that lipids play a key role in [1-93]ApoA-I aggregation in vivo.     

Experimental field test of the influence of generalist stingless bees (Meliponini) on the topology of a bee–flower mutualistic network in the tropics

1. Generalists are assumed to play a key role in structuring and stabilising animal–plant mutualistic networks. Until now, analyses on the effects of generalists have been based on empirical field data or simulations. The present natural field experiment manipulated the abundance of a generalist and abundant stingless bee [Melipona (Eomelipona) marginata] to determine the effects on the mutualistic network. 2. Networks were generated, and associated metrics were used for comparing replicate plots with and without the insertion of stingless bee nests. 3. Unweighted metrics and the basic qualitative structural pattern of networks (high nestedness, very low modularity and specialisation) was not affected by experimental variation in stingless bee abundance because they exert strong basal effects on the plant–pollinator community under natural conditions of abundance. Still, increased abundance caused significant variation in weighted nestedness and modularity and community-level specialisation. 4. Supporting predictions of neutral models, increased abundance of the stingless bee led to an increase in most of its specific metrics, expressing the expansion of its realised trophic niche. 5. During this process, specialist and other generalist bees were affected in different ways. More plant species became even more dependent on this stingless bee (increased asymmetry). 6. Long-term effects could not be inferred directly from instantaneous values of network metrics. Nonetheless, the increased abundance of the generalist stingless bee may both reduce the local level of ecological specialisation in the short term and affect the spatial distribution of less abundant and/or specialist bee species and plants in the long term.     

Observations of the effect of a New Year’s fireworks display on the behavior of the South American sea lion (Otaria flavescens) in a colony of central-south Chile

The use of fireworks has increased worldwide in recent years. Despite this, their effects on sea lions and similar species are almost undocumented. In this study, we documented some effects of the 2015 New Year’s fireworks on the behavior of South American sea lions (Otaria flavescens), a marine mammal species that utilizes coastal rookeries for breeding, resting, and care and nursing of pups. An immediate cessation of vocalizations followed the start of the fireworks and a significant decrease in the number of sea lions in the colony was registered. This provided evidence that fireworks disrupted the ongoing behavior of the South American sea lion. Further studies will be necessary to determine whether this disruption has negative consequences for these animals or whether they have evolved behavioral mechanisms for dealing with these kinds of short-term disruptive events.     

Focusing by shape change in the lens of the eye: a commentary on Young (1801) ‘On the mechanism of the eye’

In his Bakerian Lecture paper of 1801, Thomas Young provided the best account up to that time of the eye''s optical system, including refraction by the cornea and the surfaces of the lens. He built a device, an optometer, for determining the eye''s state of focus, making it possible to prescribe appropriate correction lenses. His main contribution, however, was to show that accommodation, the eye''s focusing mechanism, was not the result of changes to the curvature of the cornea, nor to the length of the eye, but was due entirely to changes in the shape of the lens, which he described with impressive accuracy. He was wrong, however, in believing that the reason the lens bulges when focusing on near objects was because it behaved as a contracting muscle. Half a century later, Helmholtz showed that the lens bulges not by its own contraction, but when it is relaxed as a result of contraction of newly discovered circular muscles in the ciliary body. This commentary was written to celebrate the 350th anniversary of the journal Philosophical Transactions of the Royal Society.     

Distribution of macroinvertebrates in the shallow part of ‘De Gijster’, a water storage lake in the Biesbosch (The Netherlands)

The composition and distribution of the macroinvertebrate fauna of the shallow part of De Gijster, a medium sized water storage lake in The Netherlands, has been studied during 1984. The numerous individuals collected belong mainly to the Oligochaeta, Diptera (Chironomidae larvae) and Mollusca. Amongst them are elements of both the former polder fauna and the river fauna. A quantitative analysis revealed data on the horizontal distribution of several taxa within the lake as well as data on the influence of the lifecycle of some taxa on the annual composition of the fauna.