Temporal Changes In Abundance Research Articles

Glycerophospholipid dysregulation after traumatic brain injury

Brain tissue is highly enriched in lipids, the majority of which are glycerophospholipids. Glycerophospholipids are the major constituents of cellular membranes and play an important role in maintaining integrity and function of cellular and subcellular structures. Any changes in glycerophospholipid homeostasis can adversely affect brain functions. Traumatic brain injury (TBI), an acquired injury caused by the impact of external forces to the brain, triggers activation of secondary biochemical events that include perturbation of lipid homeostasis. Several studies have demonstrated glycerophospholipid dysregulation in the brain and circulation after TBI. This includes spatial and temporal changes in abundance and distribution of glycerophospholipids in the injured brain. This is at least in part mediated by TBI-induced oxidative stress and by activation of lipid metabolism pathways involved in tissue repairing. In this review, we discuss current advances in understanding of the mechanisms and implications of glycerophospholipid dysregulation following TBI.

Erratum: Eyestalk Ablation to Increase Ovarian Maturation in Mud Crabs.

Erratum: Eyestalk Ablation to Increase Ovarian Maturation in Mud Crabs.

Phaeogromids of the mesopelagic marine plankton: Temporal variability of concentrations and observations of feeding structures of four species from the mesopelagic in the Mediterranean Sea.

Challengerids, phaeogromids rhizarian protists, are emblematic protists of the deep sea but are also enigmatic as they occur in very low concentrations. In previous studies, we reported on temporal changes in abundance at a near-shore mesopelagic site, but only as part of sampling of the entire microplankton assemblage, not well-suited for examining phaeogromids. Consequently, we turned to using a closing plankton net to provide material from large volumes of seawater, thus allowing for more robust estimates of concentrations and material for observations of living cells, to our knowledge the first made. Here, we report our results on the four most commonly occurring species: Challengeranium diadon, Challengereron willemoesii, Challengeria xiphodon, and Euphysetta lucani. In contrast to our previous report, we found that changes in concentrations were not related to water column stratification, and the four species roughly co-varied with time. Observations of live cells revealed that all four species deploy tentacle-like pseudopods and also very large unstructured webs of fine pseudopods. The similarities in feeding webs suggest similar prey are exploited, and the similar temporal changes in abundances suggest a common factor or factors (unknown at this time) govern their concentrations. Films of live cells are provided in Supplementary Files.

Temporal change in abundance of potential nesting cavities for wood ducks (Aix sponsa) in Northern Minnesota, United States

Wood duck females often nest in tree cavities located in large-diameter deciduous trees. Temporal changes in forest age and composition during recent decades may have influenced the abundance of stems with suitable nesting cavities in the forested portion of Northern MN, United States. Thus, we ascertained whether temporal changes in the abundance of such stems occurred in this area during six Forest Inventory and Analysis (FIA) evaluation cycles (i.e., 1977 to 2015–2019). We used FIA data and independently estimated proportions of stems with suitable cavities in different tree-species, health-status, and diameter classes to estimate change in the abundance of such stems at three spatial scales. These spatial scales increased in areal extent from a study area to three ecological subsections to the Laurentian Mixed Forest ecological province. We used a Bayesian analytical approach to accommodate changes in FIA protocols among cycles. Both the abundance of stems with suitable cavities and an attribute associated with cavity occurrence changed during the analysis period, but findings were not entirely consistent among spatial scales. The estimated abundance of both suitable stems overall and those of late-successional tree species generally increased at all scales during the analysis period. Since 1990, increases in the abundance of health-impacted stems that were suitable for nesting occurred at all spatial scales. Our estimated densities of suitable stems during the 2005–2009 (1.20 [85% CrI: 1.04–1.39] suitable stems / ha) and 2015–2019 cycles (1.41 [85% CrI: 1.21–1.63] suitable stems / ha) were substantially greater than the <0.25 and 0.25–0.49 suitable stems / ha another study predicted would occur in Northern Minnesota during 2008 and 2018, respectively. Our results can inform forest management decisions and research directions for follow-up studies of nesting wood ducks.

Environmental DNA tracks zooplankton population dynamics in experimental mesocosms

AbstractEnvironmental DNA (eDNA) holds notable potential for biomonitoring and ecological research. However, its utility for quantifying temporal changes in abundance, biomass, and diversity remains contentious. We investigated biotic and abiotic factors influencing temporal variation in eDNA concentration in large, 28,000 L experimental mesocosms. Time series data demonstrated a positive relationship between the population abundance and biomass of the Cladoceran zooplankton species Daphnia magna and eDNA concentration, with a time lag of ~3.5 days in 25°C conditions, and up to 28 days in 15°C. Water temperature variations within mesocosms did not consistently influence eDNA quantity, although water temperature negatively predicted DNA concentration across mesocosms. Algal density negatively correlated with D. magna eDNA quantity across and within mesocosms. We demonstrate that eDNA signal detection can be used as a proxy for relative abundance and suggest that future investigation into the dynamics of eDNA shedding and degradation processes is warranted.

The impacts of viral infection and subsequent antimicrobials on the microbiome-resistome of growing pigs

BackgroundAntimicrobials are used in food-producing animals for purposes of preventing, controlling, and/or treating infections. In swine, a major driver of antimicrobial use is porcine reproductive and respiratory syndrome (PRRS), which is caused by a virus that predisposes infected animals to secondary bacterial infections. Numerous antimicrobial protocols are used to treat PRRS, but we have little insight into how these treatment schemes impact antimicrobial resistance (AMR) dynamics within the fecal microbiome of commercial swine. The aim of this study was to determine whether different PRRS-relevant antimicrobial treatment protocols were associated with differences in the fecal microbiome and resistome of growing pigs. To accomplish this, we used a metagenomics approach to characterize and compare the longitudinal wean-to-market resistome and microbiome of pigs challenged with PRRS virus and then exposed to different antimicrobial treatments, and a group of control pigs not challenged with PRRS virus and having minimal antimicrobial exposure. Genomic DNA was extracted from pen-level composite fecal samples from each treatment group and subjected to metagenomic sequencing and microbiome-resistome bioinformatic and statistical analysis. Microbiome-resistome profiles were compared over time and between treatment groups.ResultsFecal microbiome and resistome compositions both changed significantly over time, with a dramatic and stereotypic shift between weaning and 9 days post-weaning (dpw). Antimicrobial resistance gene (ARG) richness and diversity were significantly higher at earlier time points, while microbiome richness and diversity were significantly lower. The post-weaning shift was characterized by transition from a Bacteroides-dominated enterotype to Lactobacillus- and Streptococcus-dominated enterotypes. Both the microbiome and resistome stabilized by 44 dpw, at which point the trajectory of microbiome-resistome maturation began to diverge slightly between the treatment groups, potentially due to physical clustering of the pigs. Challenge with PRRS virus seemed to correspond to the re-appearance of many very rare and low-abundance ARGs within the feces of challenged pigs. Despite very different antimicrobial exposures after challenge with PRRS virus, resistome composition remained largely similar between the treatment groups. Differences in ARG abundance between the groups were mostly driven by temporal changes in abundance that occurred prior to antimicrobial exposures, with the exception of ermG, which increased in the feces of treated pigs, and was significantly more abundant in the feces of these pigs compared to the pigs that did not receive post-PRRS antimicrobials.ConclusionsThe fecal microbiome-resistome of growing pigs exhibited a stereotypic trajectory driven largely by weaning and physiologic aging of the pigs. Events such as viral illness, antimicrobial exposures, and physical grouping of the pigs exerted significant yet relatively minor influence over this trajectory. Therefore, the AMR profile of market-age pigs is the culmination of the life history of the individual pigs and the populations to which they belong. Disease status alone may be a significant driver of AMR in market-age pigs, and understanding the interaction between disease processes and antimicrobial exposures on the swine microbiome-resistome is crucial to developing effective, robust, and reproducible interventions to control AMR.Aquo5tJ4SdeSfrijD3bjSqVideo

Ecological Traits and Trophic Plasticity in The Greater Pipefish Syngnathus acus in the NW Iberian Peninsula.

Simple SummaryThe population of the pipefish Syngnathus acus inhabiting Cíes Archipelago (NW Spain) was monitored in 2017–2018 for spatial and temporal changes in abundances, reproduction traits, trophic niche occupancy, and dietary regimes across reproduction states, through an isotopic (δ13C and δ15N) approach. The population consisted almost exclusively of large adults, whose abundances decreased significantly from mid-autumn after the breeding season. S. acus is a secondary consumer that prefers amphipods, but mature specimens were less selective than immature fish. The present study highlights the outstanding size of the fish and the exceptional occurrence of breeders on the studied area.The great pipefish Syngnathus acus is one of the most representative European syngnathids, being highly associated with seagrass and macroalgal beds. Surprisingly, the ecology of this large ovoviviparous marine fish has received scanty attention. The population inhabiting three sites on Cíes Archipelago (Atlantic Islands National Park, NW Spain) was monitored in 2017–2018 for spatial and temporal changes in abundances, reproduction traits, trophic niche occupancy, and dietary regimes across reproduction states, through an isotopic (δ13C and δ15N) approach. Abundances were highly variable across seasons and sites, decreasing significantly from mid-autumn. The population consisted almost exclusively of large adults that migrate by the end of the breeding season, which extended from mid-spring to summer. Operational sex ratios suggest that the species is sex-role reversed. S. acus is a secondary consumer (Trophic position = 3.36 ± 0.05), preferring amphipods but displaying annual and seasonal dietary plasticity. Mature fish were less selective than immatures (especially females), with a higher preference for amphipods (36–68%) in the former. The second most-preferred prey were carideans, copepods, or isopods, depending on the year and the reproduction state. Overall, the wider trophic niches in females and immature specimens compared to males and mature fish would indicate a higher variability in both the use of prey resources and/or their origin. The present study highlights the trophic plasticity and unique features of S. acus population in the Cíes Archipelago, especially regarding the outstanding size of the fish and the exceptional occurrence of breeders.

Spatio-temporal patterns in arctic fox (Vulpes alopex) diets revealed by molecular analysis of scats from Northeast Greenland

The arctic fox (Vulpes lagopus) is endemic to the Arctic where it holds a central position in the trophic interactions. The diet of the species has previously been described as being highly flexible, but whether this flexibility is a constant trait through time, or merely reflects fast temporal changes in abundance among prey taxa, has so far been poorly resolved. Using molecular analyses of arctic fox scats from Northeast Greenland, we first examined the temporal dynamics of arctic fox diets during the short snow-free season, and then examined whether local food availability at different sites affected arctic fox dependence on lemmings. Arctic fox diets included most terrestrial vertebrate species found in the region, and exhibited substantial temporal changes, generally reflecting the dynamic changes in prey availability from late winter through autumn. This dietary flexibility was also reflected geographically, with arctic foxes consuming a variety of local prey (mainly waterfowl and lemmings) in summer. Moreover, the dietary response of arctic foxes to changes in lemming abundance depended on access to non-lemming prey. Based on these findings, we discuss whether varying degrees of lemming-dependency, combined with geographical differences in winter food availability, may explain previously published differences in arctic fox breeding patterns in high arctic Greenland.

Loss of Giant Kelp, Macrocystis pyrifera, Driven by Marine Heatwaves and Exacerbated by Poor Water Clarity in New Zealand

Marine heatwaves (MHW) are becoming stronger and more frequent across the globe. MHWs affect the thermal physiology of all biological organisms, but wider ecosystem effects are particularly impactful when large habitat-forming foundation species such as kelps are affected. Many studies on impacts from MHWs on kelps have focused on temperature effects in isolation, except for a few studies that have integrated co-occurring stress from grazers, wave exposure and nutrient limitation. It is likely that many stressors act in concert with MHWs and exacerbate their effects. Here we analyzed satellite images over 60 months to assess temporal changes in abundance of surface canopies of the giant kelp Macrocystis pyrifera in the New Zealand coastal zone. The analysis encompassed the most extreme MHW on record (2017/18), across a 6° latitudinal gradient of four regions southward from the northern distributional limit of Macrocystis along mainland New Zealand. We tested the association of surface canopy cover of Macrocystis with sea surface temperature, temperature anomalies, chlorophyll-a (a proxy for nutrient availability) and water clarity (diffuse attenuation coefficient). We found a reduced cover of Macrocystis across all regions during and after the 2017/18 MHW, with least impact at the most southern region where the maximum temperatures did not exceed 18°C. There was also an important and significant interaction between temperature and water clarity, showing that temperature-induced kelp loss was greater when water clarity was poor. These results show that notable negative effects occurred across the coastal range of this foundation species and highlight the importance of studying MHW effects across latitudinal gradients and in concert with other co-occurring stressors.

Accurate detection and quantification of seasonal abundance of American bullfrog (Lithobates catesbeianus) using ddPCR eDNA assays

The invasive American bullfrog (Lithobates catesbeianus) imperils freshwater biodiversity worldwide. Effective management hinges on early detection of incipient invasions and subsequent rapid response, as established populations are extremely difficult to eradicate. Although environmental DNA (eDNA) detection methods provide a highly sensitive alternative to conventional surveillance techniques, extensive testing is imperative to generate reliable output. Here, we tested and compared the performance of two primer/probe assays to detect and quantify the abundance of bullfrogs in Western Europe in silico and in situ using digital droplet PCR (ddPCR). Although both assays proved to be equally target-specific and sensitive, one outperformed the other in ddPCR detection resolution (i.e., distinguishing groups of target-positive and target-negative droplets), and hence was selected for further analyses. Mesocosm experiments revealed that tadpole abundance and biomass explained 99% of the variation in eDNA concentration. Because per individual eDNA emission rates did not differ significantly among tadpoles and juveniles, and adults mostly reside out of the water, eDNA concentration can be used as an approximation of local bullfrog abundance in natural populations. Seasonal eDNA patterns in three colonized ponds showed parallel fluctuations in bullfrog eDNA concentration. An increase in eDNA concentration was detected in spring, followed by a strong peak coinciding with the breeding season (August, September or October), and continuously low eDNA concentrations during winter. With this study, we report the validation process required for appropriately implementing eDNA barcoding analyses in lentic systems. We demonstrate that this technique can serve as a solid and reliable tool to detect the early stages of bullfrog invasions and to quantify temporal changes in abundance that will be useful in coordinating large-scale bullfrog eradication programs and evaluating their efficiency.

Annual cycle of growth and population structure of the estuarine crabHemigrapsus crenulatus(Brachyura: Varunidae) off central Chile

AbstractEstuaries and saltmarshes play a fundamental role in the life cycle of many crab species. Diverse studies show that temperature and salinity modulate abundance, size frequency distribution (SFD), sex ratio and growth in crustaceans. These population parameters are usually challenging to estimate due to the high environmental variability of estuaries. Monthly samples of the estuarine crabHemigrapsus crenulatuswere taken from October 2003 to October 2004 (except July 2004) in the Tubul estuary, central Chile. We quantified temporal changes in abundance, size distribution, sex ratio and monthly growth through the annual cycle. A total of 1025 individuals were collected. Sizes ranged from 7.72–33.51 mm carapace length (CL) with a growth rate ranging between 2.13–30.5% mm CL mo−1. Size and growth rates were greater in spring-summer, suggesting a faster growth of younger crabs correlated with increasing sea temperatures in the austral summer. Overall, sex ratio was 1.75:1 in favour of males. Modal analysis identified at least seven cohorts cohabiting throughout the annual cycle. Growth parameters for males and females were the following, respectively:L∞ = 33.6 and 29.6,k= 0.69 and 0.91,t0= –0.39 and −0.28. Changes in size distribution suggested a recruitment period during autumn and winter seasons when there are lower salinities and temperature fluctuations stresses. Generalized linear models indicated that sea temperature, salinity and chlorophyll were the environmental variables that better predicted the annual patterns in the population structure.

Overexploitation and behavioral changes of the largest South Atlantic parrotfish (Scarus trispinosus): Evidence from fishers' knowledge

Assessing species conservation status and population trends is challenging especially on low and low-middle income countries mostly due to high costs. Therefore, long-term information about species gained through local ecological knowledge, can reveal threatening and overexploitation scenarios aiming to generate information for extinction risk reduction and conservation priority targets. The greenbeak parrotfish, Scarus trispinosus, is an endemic and endangered Brazilian species with records of local extinction along its distribution, however limited data on its fisheries is available. We investigated fisher's local ecological knowledge on S. trispinosus on the largest Brazilian coastal multiple-use marine protected area. We interviewed small-scale fishers regarding catches to verify temporal changes in abundance and body size. Additionally, we verified if S. trispinosus flight initiation distance, proxy of tolerance from fisher's approximation has changed over different fishers' generations. Our results revealed that the number of individuals decreased 64% over time from 1980s to 2010s with a constant decrease through time. The weight of the largest individual ever caught also decreased 67% over time. Flight initiation distance, when fishers firstly engaged on fishing activity, was smaller for more experienced fishers. Implementation of small-scale co-management strategies, together with creation and enforcement of no-take zones are essential to safeguard the remaining populations and allow the greenbeak parrotfish recovery. Our study demonstrated that local ecological knowledge on species population and behavioral changes can be used as an alternative and inexpensive approach for assessing impact on threatened species and could be applied on conservation strategies for several species and ecosystems worldwide.

Assemblages of fruit flies (Diptera: Tephritidae) along an elevational gradient in the rainforests of Papua New Guinea

Abstract Papua New Guinea (PNG) has the greatest diversity of dacine fruit fly species (Diptera: Tephritidae: Dacinae) in the world, many of which are significant agricultural pests. Although their taxonomy is relatively well known, there is limited research on their geographical and elevational distribution. We undertook a survey of PNG's fruit fly fauna along a complete elevational gradient on Mt Wilhelm (175–3700 m a.s.l.) to determine the elevational species distribution and turnover of fruit fly communities. Fruit flies were sampled using a selection of male parapheromone lures, including Zingerone, a new and promising male attractant. In total, we collected 10 700 fruit flies representing 77 species. The total abundance and species richness of fruit flies decreased with increasing elevation. Species richness was similarly high at 175 and 200 m a.s.l. (30 and 27 species) and at 700 and 1200 m a.s.l. (16 and 20 species, respectively) but dropped suddenly to only two species at 1700 m a.s.l. and to zero at all four sites above this elevation. There were no flies attracted exclusively to Zingerone. One species (Bactrocera recurrens) exhibited dramatic, temporal changes in abundance during the study period. Fruit fly assemblages were significantly influenced by both the lure type and elevation. Similarity of fruit fly communities decayed linearly with increasing elevational distance. We concluded that the upper limit of fruit fly distribution in PNG occurs between 1700 and 2200 m a.s.l. and the centre of diversity occurs between 0 and 700 m a.s.l.

Temporal variability in tropical lagoon sponges from Mauritius (Western Indian Ocean)

Coastal lagoons are subjected to complex abiotic interactions which result to strong spatio-temporal variability of lagoon-inhabiting communities. Sponges are important components of coastal lagoons, yet their temporal variability is poorly understood. Here, we investigated the temporal variability in local distribution area (LDA), abundance (number of patches) and percentage cover of three lagoon-inhabiting sponge species: Neopetrosia chaliniformis, Amphimedon navalis and Spheciospongia vagabunda from Mauritius (Western Indian Ocean), over a 6- to 8-year period (depending on species). The correlations between two known drivers of sponge temporal patterns, sea surface temperature (SST) and chlorophyll a (Chl a) concentration, were also explored. After the survey, the total LDA and percentage cover of N. chaliniformis decreased by 40.2% and 14.6%, respectively, whereas total LDA and percentage cover of S. vagabunda increased by 135.1% and 23.3%, respectively. No significant changes were seen in the total LDA and percentage cover of A. navalis. While the abundance of N. chaliniformis and A. navalis declined over the study period, the abundance of S. vagabunda increased. SST and Chl a concentration were significantly correlated with temporal changes in abundance of all species, although correlations were species-specific. However, no significant correlations were seen between the environmental parameters and changes in sponge percentage cover, except between SST and N. chaliniformis percentage cover. Our results demonstrate that lagoon sponges show species-specific patterns in temporal variability and, while some species may potentially become locally extinct over the next few decades, if trends continue other species may become more abundant or may remain stable.

Glowing, glowing, gone? Monitoring long‐term trends in glow‐worm numbers in south‐east England

Abstract The glow‐worm Lampyris noctiluca (Linnaeus, 1767) (Coleoptera: Lampyridae) is thought to be declining in the United Kingdom. Yet, much of the evidence for this is anecdotal, with a shortage of standardised long‐term data to investigate temporal changes in abundance. We present an 18‐year time series of standardised transect surveys for glowing adult females at 19 sites within south‐east England (Essex) from 2001 to 2018. We used generalised additive mixed models (GAMMs) to control for varying sampling effort, temporal autocorrelation, non‐stationarity of seasonal phenology and non‐linearity of temporal trajectories across sites. We found a significant long‐term reduction in counts of glowing female glow‐worms, after accounting for a significant shift in seasonal phenology across years, and a negative effect of warmer climatic conditions on glow‐worm abundance. Average glowing counts in south‐east England declined by ca. −3.5% per annum from 2001 to 2018, and this result held true even after a range of sensitivity tests to account for potential methodological artefacts in citizen science data collection. Temporal trajectories in abundance were strikingly out of phase across the 19 sites, suggesting that local‐scale factors in addition to climate are driving greater reduction in numbers at some sites than others. These standardised surveys present the first quantitative evidence that numbers of glow‐worms could well be declining in the United Kingdom. There is a clear signal of climate warming and drying effects on glow‐worm numbers, but a substantially greater proportion of variation in glowing female counts is explained by local‐scale site factors, such as unmanaged scrub encroachment. Conservation strategies that can mitigate local population losses could be an essential buffer against climate‐driven declines in south‐east England.

Long-term monitoring of Serengeti bird species occurrence, abundance, and habitat.

The Serengeti ecosystem contains one of the most diverse bird assemblages in Africa. We present here a data set consisting of abundances of bird species in different habitats of the Serengeti ecosystem over a 87-yr time frame. This data set comprises 66,643 georeferenced occurrences for 568 species from 1929 to 2017. Most records contain feeding location, food source, distribution status, and observation locality. The records originate from three different but complementary methodologies: points, sites, and transects. The point method (bird species records 1929-2017) is based on ad hoc observations and includes rare species or those in special habitats. These points came from published records as well from the research program of A. R. E. Sinclair and colleagues. The site method (1966-2017) is based on structured observations at sites selected to represent specific habitats, and replicated within habitats and over time. At each site, birds were recorded by sight and sound over a radius of 50m for 10min. The transect method (1997-2011) is based on road transects covering different areas of the ecosystem. Road transects were traversed using a vehicle with observers travelling at 30km/h. Bird species were those easily seen from a vehicle out to 50m either side. As most transects were traversed multiple times, this method provides information on temporal change in abundance for a select set of species. No copyright restrictions apply to the use of this data set other than citing this publication.

Population survey showing hope for population recovery of the critically endangered Yangtze finless porpoise

The Yangtze finless porpoise (Neophocaena asiaeorientalis asiaeorientalis), has experienced rapid declines in recent decades. We estimate its abundance based on surveys conducted between November and December 2017 in the main-stem of the Yangtze River and adjacent Poyang and Dongting Lakes. We compare these to published abundance estimates from 2006 and 2012, using a bootstrap resampling approach to make inference about population change over the 2006–2017 time period. Encounter rates of porpoise from additional surveys during this period provided another index for evaluating temporal changes in abundance in Poyang and Dongting Lakes. As of December 2017, free-ranging populations of this species are estimated at 1012 (95%CI: 791–1233) individuals of which 445 (95%CI: 295–595) occur in the main stem of the Yangtze River, 457 (95%CI: 329–634) in Poyang Lake, and 110 (95%CI: 65–187) in Dongting Lake. Porpoise numbers in main-stem of the Yangtze River and Dongting Lake declined rapidly from 2006 to 2012 (mean annual rates of −14% and −12%, respectively). These rates of decline greatly eased from 2012 to 2017 (−2.5% and +3% annual growth, respectively). In Poyang Lake, the encounter rates of porpoise have remained relatively stable between 2006 and 2017. This improved population trajectory was likely a joint consequence of government and public conservation efforts. However, fragmentation of porpoise populations in Yangtze River main-stem and significantly reduced migratory movements between the two adjoining lakes and the Yangtze main stem pose a continued threat to the long-term viability of this species. Further actions to improve habitat connectivity are urgently needed.

Temporal changes in abundance-occupancy relationships over 40years.

Abundance–occupancy (A–O) relationships are widely documented for many organismal groups and regions, and have been used to gain an understanding of regional population and community trends. Monitoring changes in abundance and occupancy over time may be what is required to document changes in conservation status and needs for some species, communities, or areas.We hypothesize that if there is a higher proportion of declining species in one group of species compared with another (e.g., migratory species vs. permanent residents), then a consequence of that difference will be vastly different abundance–occupancy relationships. If this difference persists through time, then the resulting A–O relationships between the groups will continue to diverge.For neotropical migrants, short‐distance migrants, and permanent resident birds of North America, we assess the numbers of declining species over 1969–2009. We further test for differences in the A–O relationship across these three groups, and in rates of change in abundance and occupancy separately.We find significant differences in numbers of declining species across the migratory groups, a significant decline in the A–O relationship for permanent residents, a significant increase for Neotropical migrants, and a nonsignificant decline for short‐distance migrants over the 40 years. Further, abundances are not changing at different rates but occupancies are consistently greater over time for neotropical migrants versus permanent residents, likely driving the changes in A–O relationships observed.In these analyses, we documented changing A–O trends for different groups of species, over a relatively long time period for ecological studies, one of only a few studies to examine A–O relationships over time. Further, we have shown that a temporally unvarying abundance–occupancy relationship is not universal, and we posit that variability in A–O relationships is due to human impacts on habitats, coupled with variation in species' abilities to respond to human impacts.

Molecular characterization of a vitellogenesis-inhibiting hormone (VIH) in the mud crab (Scylla olivacea) and temporal changes in abundances of VIH mRNA transcripts during ovarian maturation and following neurotransmitter administration

The vitellogenesis-inhibiting hormone (VIH), also known as gonad-inhibiting hormone, is a neuropeptide hormone in crustaceans that belongs to the crustacean hyperglycemic hormone (CHH)-family peptide. There is regulation vitellogenesis by VIH during gonad maturation in crustaceans. A full-length Scylla olivacea VIH (Scyol-VIH) was identified through reverse transcription polymerase chain reaction and rapid amplification of cDNA ends. The open reading frame consists of 378 nucleotides, which encodes a 126-amino acid precursor protein, including a 22-residue signal peptide and a 103-amino acid mature peptide in which 6 highly conserved cysteine residues are present. There was expression of the Scyol-VIH gene in immature female Scylla olivacea in the eyestalk, brain and ventral nerve cord. The Scyol-VIH gene expression was localized to the eyestalk X-organ, brain neuronal clusters 6 and 11, and in multiple neuronal clusters of the ventral nerve cord. The relative abundance of Scyol-VIH mRNA transcript in the eyestalk was relatively greater in immature stage females, then decreased as ovarian maturation progressed. Furthermore, eyestalk Scyol-VIH increased after dopamine (5 μg/g BW) injection. The present research provides fundamental information about Scyol-VIH and its potential effect in controlling reproduction.

Decadal variability in sponge abundance and biodiversity on an Indo-Pacific coral reef

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 620:63-76 (2019) - DOI: https://doi.org/10.3354/meps12968 Decadal variability in sponge abundance and biodiversity on an Indo-Pacific coral reef Alberto Rovellini1,*, Matthew R. Dunn2, Elizabeth A. Fulton3, Nicole S. Webster4,5, David J. Smith6, Jamaluddin Jompa7, Abdul Haris7, Jade Berman8, James J. Bell1 1School of Biological Sciences, Victoria University of Wellington, Wellington 6012, New Zealand 2National Institute of Water and Atmospheric Research (NIWA), Wellington 6021, New Zealand 3CSIRO Oceans and Atmosphere, Hobart, Tasmania 7004, Australia 4Australian Institute of Marine Science, Townsville, Queensland 4810, Australia 5Australian Centre for Ecogenomics, The University of Queensland, Brisbane, Queensland 4072, Australia 6Coral Reef Research Unit, School of Biological Sciences, University of Essex, Colchester CO4 3SQ, UK 7Universitas Hasanuddin, Department of Marine Science, Makassar 90245, Indonesia 8Ulster Wildlife, Belfast, Northern Ireland BT3 9LE, UK *Corresponding author: alberto.rovellini@vuw.ac.nz ABSTRACT: Natural communities can undergo large temporal changes in abundance and species composition that may be difficult to detect without long-term ecological monitoring. Characterizing temporal variability in coral reef fauna is critical for predicting how reef ecosystems will be impacted by environmental change. Sponges are an ecologically important component of coral reefs, yet descriptions of temporal dynamics of multi-species sponge assemblages are scarce. We studied temporal changes in abundance and biodiversity of an Indonesian coral reef sponge assemblage over 13 yr (2005-2017). Mean (±SE) sponge abundance (sponge patches m-2) initially increased from 124.06 ± 8.46 to 183.73 ± 12.12 in 2005-2007 (p < 0.001), declined to 66.53 ± 10.62 in 2007-2014 (p < 0.001), and increased to 105.87 ± 15.42 in 2014-2017 (p < 0.001). These patterns in sponge abundance did not depend on water temperature. Overall, we recorded 141 sponge taxa. However, species composition showed strong temporal patterns driven by a few abundant taxa (e.g. Protosuberites sp., Sycon sp., and Pericharax sp., respectively accounting on average for ~25, 20, and 5% of total sponge abundance). Species richness increased with sponge abundance (p < 0.001), whereas evenness decreased due to dominance of some taxa in years of high sponge abundance (p = 0.002). Our study highlights that the abundance and biodiversity of Indo-Pacific sponge assemblages undergo dramatic temporal changes driven by species-specific population variability. This variability has important implications for designing monitoring programs, for interpreting experimental studies, and for understanding long-term responses of coral reefs to perturbations. KEY WORDS: Sponge assemblage · Porifera · Indo-Pacific · Population variability · Long-term monitoring · Sponge diversity Full text in pdf format Supplement 1Supplement 2 PreviousNextCite this article as: Rovellini A, Dunn MR, Fulton EA, Webster NS and others (2019) Decadal variability in sponge abundance and biodiversity on an Indo-Pacific coral reef. Mar Ecol Prog Ser 620:63-76. https://doi.org/10.3354/meps12968 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 620. Online publication date: June 18, 2019 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2019 Inter-Research.