Hasil untuk "Natural history (General)"

Ryan M. Tharp, Nathan J. Hostetter, Avery B. Paxton et al.

Artificial reefs can play an important role in marine fisheries management by supplementing or enhancing natural habitats. Despite their increased use in recent years, the choice of structures used at artificial reefs remains largely haphazard due to the lack of information on reef structure performance. Few studies have examined the use of different artificial reef structures by individual fish. From 2021-2022, we acoustically tagged 72 black sea bass (Centropristis striata), 34 gag (Mycteroperca mircrolepis), 27 greater amberjack (Seriola dumerili), nine almaco jack (S. rivoliana), and eight red snapper (Lutjanus campechanus) on four artificial reef complexes near Cape Lookout, North Carolina, U.S. Available artificial reef structures consisted of materials of various sizes and heights made of concrete and metal. We tracked tagged fish using a fine-scale positioning system for ~100 days. Black sea bass exhibited high site fidelity to the artificial structure where we caught them, rarely moving away from that structure. The limited movement resulted in low transition probabilities; we conclude that black sea bass do not select for particular artificial structures. Gag and red snapper moved greater distances away from artificial structures and routinely moved between them. Greater amberjack and almaco jack moved the most within the complexes displaying circling behavior around individual structures and were the only species that regularly moved off the artificial reef complexes. Greater amberjack movements away from artificial sites were most commonly directed to surrounding shipwrecks. Whereas gag, red snapper, almaco jack, and greater amberjack used all available structures, they consistently selected for high relief structures, such as vessels, more than other structures. These results will be useful to managers charged with decisions on what types of structures to place at artificial reef complexes to supplement or enhance habitat for economically important fishes.

Bayan M. Aldraiwish, Maha M. Alaqeel, Nawal Al-Hoshani et al.

IntroductionThe current experiment investigated the multifaceted effects induced by microplastics and the statin Lipitor on marine benthic nematodes.MethodsThe nematodes were exposed to a single polystyrene and polyvinyl chlorides (both at 1 mg.kg-1 Dry Weight) and two Lipitor concentrations (0.1 and 1 mg.l-1), as well as to a mixture of both types of pollutants, for 30 days.ResultsThe results highlighted a significant decrease in the abundance, individual biomass, and diversity of nematodes directly with the addition of polyvinyl chlorides and/or Lipitor. These treatments induced a greater mortality rate among microvores and diatom feeders compared to other feeding types of nematodes.DiscussionThe nematofauna underwent a strong restructuring phase following exposure to microplastics and Lipitor when added alone, leading to the disappearance of sensitive species and their replacement by more tolerant taxa. The toxicity of Lipitor is attenuated by the physical bonding with polystyrene when added to a mixture and has no negative effect on marine nematode species.

Hannah C. Barkley, Thomas A. Oliver, Ariel A. Halperin et al.

The U.S. Pacific Islands span a dramatic natural gradient in climate and oceanographic conditions, and benthic community states vary significantly across the region’s coral reefs. Here we leverage a decade of integrated ecosystem monitoring data from American Samoa, the Mariana Archipelago, the main and Northwestern Hawaiian Islands, and the U.S. Pacific Remote Island Areas to evaluate coral reef community structure and reef processes across a strong natural gradient in pH and aragonite saturation state (Ωar). We assess spatial patterns and temporal trends in carbonate chemistry measured in situ at 37 islands and atolls between 2010 and 2019, and evaluate the relationship between long-term mean Ωar and benthic community cover and composition (benthic cover, coral genera, coral morphology) and reef process (net calcium carbonate accretion rates). We find that net carbonate accretion rates demonstrate significant sensitivity to declining Ωar, while most benthic ecological metrics show fewer direct responses to lower-Ωar conditions. These results indicate that metrics of coral reef net carbonate accretion provide a critical tool for monitoring the long-term impacts of ocean acidification that may not be visible by assessing benthic cover and composition alone. The perspectives gained from our long-term, in situ, and co-located coral reef environmental and ecological data sets provide unique insights into effective monitoring practices to identify potential for reef resilience to future ocean acidification and inform effective ecosystem-based management strategies under 21st century global change.

Sha Sun, Jieping Liu, Sen Zhang et al.

Sex is one of the most important scientific topics, and the existence of sex dimorphism is a conserved feature in vertebrate taxa. The research on sex-determining genes and sex chromosome evolution is a hot topic in biology. The majority of sex-determining genes expressed in somatic cells, and reciprocal interactions between germ cells and somatic cells, are important for gonadal differentiation. However, the knowledge of how signals are transmitted between somatic cells and germ cells remains unclear. In this study, we confirmed the 36 dph was a sex determination critical stage in yellow drum through transcriptome analysis at the early development stages. We further found that Kank1 participated in the germ cells’ motility process in yellow drum through KEGG pathway analysis together with protein-protein interaction network. With the dual-luciferase reporter assay, we detected that Kank1 increased the transcription of dmrt1_Luc gene in CHO cells and 293T cells. Additionally, we observed that Kank1 was not only expressed in the cytoplasm but also in the nucleus in CHO cells through a fluorescence microscope. These results suggest that Kank1 acts as a shuttling protein as in humans and may play a difunctional role at the early gonad development stage in yellow drum, and it not only participated in the germ cells’ motility but also increased the expression of dmrt1 in yellow drum.

Amibeth Thompson, Mark Frenzel, Oliver Schweiger et al.

In order to synthesize changes in pollinating insect communities across space and time, it is necessary to understand whether, and how, sampling methods influence assessments of community patterns. We compared how two common sampling methods—yellow combined flight traps and net sampling—influence our understanding of the species richness, abundance and composition of wild bees and hoverflies, and addressed whether these patterns resulted from potentially biased sampling of individuals or species with different types of functional traits. We sampled bee and hoverfly communities in six sites over three seasons in Saxony-Anhalt, Germany. We captured more species and individuals of bees with traps and more species and individuals of hoverflies with net sampling. However, rarefied richness results were less dramatic between the sampling methods for bees and were not different between the sampling methods for hoverflies. Thus, differences in species richness across sampling methods were mostly due to differences in the number of individuals captured in the different methods. We captured more small-sized bees and hoverflies with traps. We tested if the different methods collected individuals and species with different functional traits, such as nesting preferences, sociality and flower specialization for bees and floral preference, migratory status and habitat preference for hoverflies. For most traits, we collected more individuals but not more species with a certain trait in the different methods. This was mainly due to a high abundance of one species being collected in the different methods. These results suggest that the best methodology depends on the aim of the survey, and that the methods cannot be easily combined into synthesis research. Our results have implications for the development of monitoring schemes for pollinators and for synthesis of trends that can identify threats to pollinators and inform research of pollinator conservation strategies.

Ruping Ge, Ruping Ge, Hongju Chen et al.

The active carbon flux mediated by diel vertical migration (DVM) of zooplankton is an important component of the downward carbon flux in the ocean. However, active fluxes transported by zooplankton DVM are poorly known in the South China Sea (SCS) and the Western Philippine Sea (WPS). In this study, active carbon fluxes in the SCS and WPS were evaluated on the basis of the data of mesozooplankton community and DVM at two stations of these areas. The mesozooplankton community in the SCS was obviously different from that in the WPS, and higher species number and abundance in the SCS were observed, which may be related to the higher chlorophyll a (Chl a) concentration and the wide gradients of temperature and salinity in this sea. Moreover, shallow depth Chl a maximum and strong thermocline were detected in the SCS, causing lower migration amplitudes of mesozooplankton in the SCS than those in the WPS. However, the migrant biomass of mesozooplankton in the SCS was 98.40 mg C m–2, higher than that in the WPS at 25.12 mg C m–2. The mesozooplankton active carbon flux in the SCS (4.64 mg C m–2⋅d–1) was also higher than that in the WPS (1.80 mg C m–2⋅d–1). The mesozooplankton active fluxes were equivalent to 8.3 and 8.1% of the total flux (active flux plus passive flux) of the SCS and WPS, respectively, and they play an important role in the biological pump functioning in the two regions.

Cathy Wimart-Rousseau, Thibaut Wagener, Marta Álvarez et al.

The seasonal variability of the carbonate system in the eastern Mediterranean Sea (EMed) was investigated based on discrete total alkalinity (AT), total dissolved inorganic carbon (CT), and pH measurements collected during three cruises around Crete between June 2018 and March 2019. This study presents a detailed description of this new carbonate chemistry dataset in the eastern Mediterranean Sea. We show that the North Western Levantine Basin (NWLB) is unique in terms of range of AT variation vs. CT variation in the upper water column over an annual cycle. The reasons for this singularity of the NWLB can be explained by the interplay between strong evaporation and the concomitant consumption of CT by autotrophic processes. The high range of AT variations, combined to temperature changes, has a strong impact on the variability of the seawater pCO2 (pCO2SW). Based on Argo float data, an entire annual cycle for pCO2SW in the NWLB has been reconstructed in order to estimate the temporal sequence of the potential “source” and “sink” of atmospheric CO2. By combining this dataset with previous observations in the NWLB, this study shows a significant ocean acidification and a decrease in the oceanic surface pHT25 of −0.0024 ± 0.0004 pHT25 units.a–1. The changes in the carbonate system are driven by the increase of atmospheric CO2 but also by unexplained temporal changes in the surface AT content. If we consider that the EMed will, in the future, encounter longer, more intense and warmer summer seasons, this study proposes some perspectives on the carbonate system functioning of the “future” EMed.

Ting Lv, AJ Harris, Yuping Liu et al.

Abstract Psammochloa villosa is an ecologically important desert grass that occurs in the Inner Mongolian Plateau where it is frequently the dominant species and is involved in sand stabilization and wind breaking. We sought to generate a preliminary demographic framework for P. villosa to support the future studies of this species, its conservation, and sustainable utilization. To accomplish this, we characterized the genetic diversity and structure of 210 individuals from 43 natural populations of P. villosa using amplified fragment length polymorphism (AFLP) markers. We obtained 1,728 well‐defined amplified bands from eight pairs of primers, of which 1,654 bands (95.7%) were polymorphic. Results obtained from the AFLPs suggested effective alleles among populations of 1.32, a Nei's standard genetic distance value of 0.206, a Shannon index of 0.332, a coefficient of gene differentiation (GST) of 0.469, and a gene flow parameter (Nm) of 0.576. All these values indicate that there is abundant genetic diversity in P. villosa, but limited gene flow. An analysis of molecular variance (AMOVA) showed that genetic variation mainly exists within populations (64.2%), and we found that the most genetically similar populations were often not geographically adjacent. Thus, this suggests that the mechanisms of gene flow are surprisingly complex in this species and may occur over long distances. In addition, we predicted the distribution dynamics of P. villosa based on the spatial distribution modeling and found that its range has contracted continuously since the last interglacial period. We speculate that dry, cold climates have been critical in determining the geographic distribution of P. villosa during the Quaternary period. Our study provides new insights into the population genetics and evolutionary history of P. villosa in the Inner Mongolian Plateau and provides a resource that can be used to design in situ conservation actions and prioritize sustainable utilization.

Markus Pfenninger, Friederike Reuss, Angelika Kiebler et al.

In the course of global climate change, Central Europe is experiencing more frequent and prolonged periods of drought. The drought years 2018 and 2019 affected European beeches (Fagus sylvatica L.) differently: even in the same stand, drought-damaged trees neighboured healthy trees, suggesting that the genotype rather than the environment was responsible for this conspicuous pattern. We used this natural experiment to study the genomic basis of drought resistance with Pool-GWAS. Contrasting the extreme phenotypes identified 106 significantly associated single-nucleotide polymorphisms (SNPs) throughout the genome. Most annotated genes with associated SNPs (>70%) were previously implicated in the drought reaction of plants. Non-synonymous substitutions led either to a functional amino acid exchange or premature termination. A non-parametric machine learning approach on 98 validation samples yielded 20 informative loci which allowed an 88% prediction probability of the drought phenotype. Drought resistance in European beech is a moderately polygenic trait that should respond well to natural selection, selective management, and breeding.

Jaime A. Chaves, Pedro J. Martinez-Torres, Emiliano A. Depino et al.

The biotas of the Galápagos Islands are one of the best studied island systems and have provided a broad model for insular species’ origins and evolution. Nevertheless, some locally endemic taxa, such as the Galápagos Rail <i>Laterallus spilonota</i>, remain poorly characterized. Owing to its elusive behavior, cryptic plumage, and restricted distribution, the Galápagos Rail is one of the least studied endemic vertebrates of the Galapagos Islands. To date, there is no genetic data for this species, leaving its origins, relationships to other taxa, and levels of genetic diversity uncharacterized. This lack of information is critical given the adverse fate of island rail species around the world in the recent past. Here, we examine the genetics of Galápagos Rails using a combination of mitogenome <i>de novo</i> assembly with multilocus nuclear and mitochondrial sequencing from both modern and historical samples. We show that the Galápagos Rail is part of the “American black rail clade”, sister to the Black Rail <i>L. jamaicensis</i>, with a colonization of Galápagos dated to 1.2 million years ago. A separate analysis of one nuclear and two mitochondrial markers in the larger population samples demonstrates a shallow population structure across the islands, possibly due to elevated island connectivity. Additionally, birds from the island Pinta possessed the lowest levels of genetic diversity, possibly reflecting past population bottlenecks associated with overgrazing of their habitat by invasive goats. The modern and historical data presented here highlight the low genetic diversity in this endemic rail species and provide useful information to guide conservation efforts.

Herbeson Ovidio de Jesus Martins, Patricia Luiza de Oliveira Rebouças, Vinina Silva Ferreira

Mesonychium asteria (Smith) is a cleptoparasitic bee with occurrence restricted to South America. In this study, we provide new information related to the host association and cleptoparasitic behavior of this species in nests of Centris xanthomelaena Moure & Castro. Observations were conducted at the nesting sites of C. xanthomelaena in a Caatinga area of Pernambuco state, Brazil. Females of M. asteria were observed performing overflying in nest aggregations and attacking some nests. We have confirmed the cleptoparasitic association with the emergence of adult M. asteria from the host bee nests, and also by the presence of its larva on the brood cells.

Adriana Almeida de Lima, Milton Cezar Ribeiro, Carlos Eduardo de Viveiros Grelle et al.

Changes in Earth's climatic conditions may affect the geographic distributions of species causing variations in diversity patterns through space and time. Projections of species distributions over time can measure how future climate scenarios will affect communities. We investigated how climate changes scenarios will influence primate biodiversity patterns in the Atlantic Forest. Specifically: (i) where are the largest changes in species richness expected? (ii) the spatial pattern of beta diversity will undergo homogenisation or heterogenisation? and (iii) where will occur the major changes in temporal beta diversity? We generated current and future species distribution models for Brazilian Atlantic Forest primates. We analysed the changes in the spatio-temporal patterns of alpha and beta diversity. Current high richness patterns will be maintained in future scenarios, with richer areas concentrated in the coastal zones. Regions closer to Cerrado will face a reduction in primate richness. Changes in richness will occur predominantly due to species loss. Communities will be more spatially heterogeneous in the future, with increased beta diversity. The heterogenisation may be driven by the reduction of species geographic distributions. The highest temporal changes will occur mainly in the midwest and the central region of the biome. Climate changes will cause primates diversity changes in both space and time. These changes will not be homogeneous through the Atlantic Forest. Our study is informative at a large spatial scale, providing an outlook on the impact of climate change on primate diversity, and indicating places of primates’ biodiversity maintenance, loss or gain due to climate change.

Saulius Pivoras

This article aims to identify and reconstruct a few main elements of political theory upon which the works of Simonas Daukantas, the founding father of the national Lithuanian written history, are based. Daukantas’s major works on Lithuanian history were researched while identifying and closely analyzing the passages where Daukantas specifically speaks about natural law and civilizational progress. Daukantas’s history works were considerably influenced by authors of Neostoic natural law theory, such as Hugo Grotius, Samuel Pufendorf, and Antoine-Yves Goguet. This influence shows in the adopted conceptions of natural needs, natural sociability, and a characterization of the emergence of private property rights in Lithuania with the help of conjectural history methods. Daukantas traces natural law elements in the oldest customs of the people and therefore gives most attention to reconstructing and describing the mores of the ancient Lithuanians. In describing historical evolution, he applied in his works the concepts of bright and dark periods as well as the distinctions of other separate stages of civilizational progress as discussed in Enlightenment historiography and conjectural history in particular.

Diva J. Amon, Judith Gobin, Cindy L. Van Dover et al.

Exploration of the deep ocean (&gt;200 m) is taking on added importance as human development encroaches. Despite increasing oil and natural gas exploration and exploitation, the deep ocean of Trinidad and Tobago is almost entirely unknown. The only scientific team to image the deep seafloor within the Trinidad and Tobago Exclusive Economic Zone was from IFREMER in the 1980s. That exploration led to the discovery of the El Pilar methane seeps and associated chemosynthetic communities on the accretionary prism to the east of Trinidad and Tobago. In 2014, the E/V Nautilus, in collaboration with local scientists, visited two previously sampled as well as two unexplored areas of the El Pilar site between 998 and 1,629 m depth using remotely operated vehicles. Eighty-three megafaunal morphospecies from extensive chemosynthetic communities surrounding active methane seepage were observed at four sites. These communities were dominated by megafaunal invertebrates including mussels (Bathymodiolus childressi), shrimp (Alvinocaris cf. muricola), Lamellibrachia sp. 2 tubeworms, and Pachycara caribbaeum. Adjacent to areas of active seepage was an ecotone of suspension feeders including Haplosclerida sponges, stylasterids and Neovermilia serpulids on authigenic carbonates. Beyond this were large Bathymodiolus shell middens. Finally there was either a zone of sparse octocorals and other non-chemosynthetic species likely benefiting from the carbonate substratum and enriched production within the seep habitat, or sedimented inactive areas. This paper highlights these ecologically significant areas and increases the knowledge of the biodiversity of the Trinidad and Tobago deep ocean. Because methane seepage and chemosynthetic communities are related to the presence of extractable oil and gas resources, development of best practices for the conservation of biodiversity in Trinidad and Tobago waters within the context of energy extraction is critical. Potential impacts on benthic communities during oil and gas activities will likely be long lasting and include physical disturbance during drilling among others. Recommendations for the stewardship of these widespread habitats include: (1) seeking international cooperation; (2) holding wider stakeholder discussions; (3) adopting stringent environmental regulations; and (4) increasing deep-sea research to gather crucial baseline data in order to conduct appropriate marine spatial planning with the creation of marine protected areas.

G. E. Estrada, D. W. Sierra, D. J. Castaño et al.

El Municipio de Paujil- Caquetá esta ubicado en el piedemonte amazónico, por lo que cuenta con una abundante biodiversidad; sin embargo, por sus características sociales y culturales, se hace fiecuente la tenencia en cautiverio de fauna silvestre, principalmente con fines de amansamientos para ser conservados como animales de compañía o para su comercialización ilegal. La investigación fue desarrollada a principio del año 2010, en el perímetro urbano de El paujil - Caquetá mediante el uso de listas de chequeo, demostró que los animales mas frecuentemente mantenidos en cautiverio son aves, especialmente loras. seguidas por reptiles y en último lugar los mamífero, contrario a los reportes de la Policía del Departamento del Caquetá, que para el primer periodo del año 2010, reportó mayores índices de decomisos en reptiles, especialmente Chelonios. Se confirmó que la razón de tenencia corresponde a necesidades antrópicas no vitales, como servir de animales de compañía, y que la práctica se concentra en los estratos uno y dos, La falta de conocimiento específico de las especies y su manejo, hace que los tenedores de fauna silvestre en cautiverio estén expuestos a todos los riesgos que supone la interacción con este tipo de animales, entre los que se encuentran las agresiones físicas, pero muy especialmente la transmisión de enfermedades zoontiticos.

Allen Szalanski, Amber Tripodi

<p>An assessment of a molecular diagnostic technique for distinguishing Africanized honey bees from European honey bees in the United States was conducted. Results from multiplex PCR diagnostics of a mitochondrial DNA cyt-b marker corresponded with results based on COI-COII sequencing analysis, but differed from morphometric analysis results. We suggest utilizing both multiplex PCR and morphometric methods for Africanized honey bee diagnostics in the United States, when possible.</p>

L. Tamang, B. Sinha

This paper communicates the extension of the distribution range of Batasio merianiensis in Sille River in the upper Brahmaputra drainage, East Siang District, Arunachal Pradesh. Detailed examinations of the specimens revealed existence of few morphological variations against those reported by Heok Hee Ng in 2009 on the following characteristics: by having a longer preanal (70.4-73.4 vs. 66.3-68.2% SL); a longer prepectoral (25.1-29.3 vs. 21.4-25.7% SL); a longer adipose-fin base (22.0-27.6 vs. 16.9-22.2% SL); a shorter post-adipose distance (11.6-13.4 vs.13.4-15.5% SL); a deeper body at anus (depth 18.3-20.8 vs.15.2-18.4% SL) and broader head (width 17.6-20.0 vs.13.5-16.2 % HL). Few additional characters of the fish are included along with brief information on its habitat. The LIPUM, the semi-traditional method of fishing in the river is identified as a major threat to this species.

David M. Kalb, Jacob L. Bowman

ABSTRACT We present the retention rate of expandable radiocollars that can be used on juvenile cervids. These collars permit investigations into a previously understudied segment of cervid populations. We captured 60 male sika deer (Cervus nippon) in Dorchester County, Maryland, USA, during their first winter (6–8 months of age; captured 2008 and 2009) and attached expandable radiocollars. Retention of collars differed between years. The first year, 85% of collars were retained for 1 year with a mean retention time of 532 days (SE = 27). After modifications, 100% of second‐year collars were retained for the duration of the study or until the animal's death (max = 483 days). We used trail cameras to observe wear and fit of the collars 6–8 months after deployment. Our data suggest that the expandable collar design can be improved to last beyond an animal's dispersal and provide a useful tool for monitoring juvenile cervids. © 2014 The Wildlife Society.

G PARKER, S HOLMES, V MANICAVASAGAR