590 Tiere (Zoologie)
Refine
Year of publication
- 2019 (217) (remove)
Document Type
- Part of Periodical (128)
- Article (87)
- Doctoral Thesis (1)
- Preprint (1)
Language
- English (217) (remove)
Has Fulltext
- yes (217) (remove)
Is part of the Bibliography
- no (217)
Keywords
- taxonomy (57)
- new species (32)
- Odonata (11)
- morphology (11)
- Neotropical region (10)
- South America (8)
- Taxonomy (8)
- systematics (6)
- Neotropical (5)
- damselflies (5)
Institute
- Institut für Ökologie, Evolution und Diversität (15)
- Senckenbergische Naturforschende Gesellschaft (14)
- Biowissenschaften (11)
- Biodiversität und Klima Forschungszentrum (BiK-F) (8)
- Geowissenschaften (2)
- MPI für Hirnforschung (2)
- Biochemie und Chemie (1)
- Exzellenzcluster Makromolekulare Komplexe (1)
- Geowissenschaften / Geographie (1)
- Kulturwissenschaften (1)
Small-scale phenotypic differentiation along complex stream gradients in a non-native amphipod
(2019)
Background: Selective landscapes in rivers are made up by an array of selective forces that vary from source to downstream regions or between seasons, and local/temporal variation in fitness maxima can result in gradual spatio-temporal variation of phenotypic traits. This study aimed at establishing freshwater amphipods as future model organisms to study adaptive phenotypic diversification (evolutionary divergence and/or adaptive plasticity) along stream gradients.
Methods: We collected Gammarus roeselii from 16 sampling sites in the Rhine catchment during two consecutive seasons (summer and winter). Altogether, we dissected n = 1648 individuals and quantified key parameters related to morphological and life-history diversification, including naturally selected (e.g., gill surface areas) as well as primarily sexually selected traits (e.g., male antennae). Acknowledging the complexity of selective regimes in streams and the interrelated nature of selection factors, we assessed several abiotic (e.g., temperature, flow velocity) and biotic ecological parameters (e.g., conspecific densities, sex ratios) and condensed them into four principal components (PCs).
Results: Generalized least squares models revealed pronounced phenotypic differentiation in most of the traits investigated herein, and components of the stream gradient (PCs) explained parts of the observed differences. Depending on the trait under investigation, phenotypic differentiation could be ascribed to variation in abiotic conditions, anthropogenic disturbance (influx of thermally polluted water), or population parameters. For example, female fecundity showed altitudinal variation and decreased with increasing conspecific densities, while sexual dimorphism in the length of male antennae—used for mate finding and assessment—increased with increasing population densities and towards female-biased sex ratios.
Conclusions: We provide a comprehensive protocol for comparative analyses of intraspecific variation in life history traits in amphipods. Whether the observed phenotypic differentiation over small geographical distances reflects evolutionary divergence or plasticity (or both) remains to be investigated in future studies. Independent of the mechanisms involved, variation in several traits is likely to have consequences for ecosystem functions. For example, leaf-shredding in G. roeselii strongly depends on body size, which varied in dependence of several ecological parameters.
Description of Hemicordulia tuiwawai sp. nov. from Kadavu Island, Fiji (Odonata: Corduliidae)
(2019)
Hemicordulia tuiwawai sp. nov. (Odonata: Corduliidae) is described and diagnosed based on material collected from Kadavu Island, Fiji; holotype: Wainitayuki River about 750 m above Baidamudamu village, -19.0916, 178.1038; 37 m a.s.l., 06 June 2016, M. Marinov leg. This species is distinguished from its congeners in the field by the contrasting colouration – dark green metallic body with bright yellow spots on the synthorax and base of the abdomen. This pattern is comparable to H. pacifica Selys, 1871. However, Hemicordulia tuiwawai sp. nov. can be recognised by the larger size and unique shape of the caudal appendages and genital hamule (in males) and vulvar scale (in females).
Records of Odonata from the southwest of Sri Aman Division and the extreme east of Serian Division in Sarawak are presented. The sampled areas are interesting not only because they are poorly known for Odonata but also because many are just to the south and west of the Lupar Line which is a division between the ancient Sunda shelf and more recent geological formations. Differences between the odonate faunas on either side of the Lupar Line are discussed. Eightyfive species of Odonata were recorded during the surveys reported on. The single most notable record is that of Coeliccia southwelli Dow & Reels, 2011, which represents a considerable extension to the known range of this species. Other interesting records include Telosticta dupophila (Lieftinck, 1933), T. species cf longigaster Dow & Orr, 2012, Podolestes parvus Dow & Ngiam, 2019 and Heliogomphus species cf olivaceous Lieftinck, 1961. Variation in the markings of Stenagrion dubium (Laidlaw, 1912) across its range is discussed and a gene tree using the COI marker is presented to illustrate the high variability of this species in this marker. However the variability in COI does not appear to be correlated with other characters.
Odonatological results of a trip across the southern Far East of Russia, from nearly the border of North Korea to Khabarovsk from July 1st to 16th, 2014, are presented. In total, 50 species were recorded, including those with limited presence in Russia, such as Paracercion calamorum, P. hieroglyphicum, P. plagiosum (for this species the 3rd Russian locality is reported), Pseudocopera tokyoensis, Stylurus annulatus (2nd Russian locality), Sinictinogomphus clavatus; Trigomphus citimus, Macromia daimoji (3rd Russian locality), M. manchurica, Deielia phaon, Lyriothemis pachygastra (2nd Russian locality). For S. annulatus, M. manchurica and D. phaon the northernmost known localities in the world are reported. D. phaon, earlier reported from one locality in Russia, have been found in five localities in Primorye and for the first time reported for Khabarovskiy Kray in general and Bol'shekhekhtsirskiy State Nature Reserve in particular. A trend of mutual exclusion of two abundant Shaogomphus postocularis epophthalmus and S. schmidti is supposed: the lowermost Ussuri River / Amur River, respectively. Variation in Paracercion spp. and Macromia amphigena fraenata is discussed.
During four field trips in Georgia, Armenia and Azerbaijan from 2010 to 2018, the author collected data of a total of 55 species (see Tab. 2 in Appendix). This study provides first insights into new or rare species in this ecoregion. Ischnura fountaineae and Cordulia aenea were found for the first time in Armenia. We also highlight the rediscovery of some species that were mentioned in the older literature but had not been confirmed since. An autochthonous population of Lestes macrostigma was discovered in Azerbaijan sixteen years after the single previous record by Dumont (2004). Original information is provided on the distribution of some rare species encountered in these countries. Finally, the identification of a puzzling Cordulegaster sp. observed in south Armenia is discussed briefly.
The Odonata collection deposited at the Museum of Comparative Zoology (MCZ) includes specimens of 634 taxa labeled as types. Fifteen of these have been incorrectly labeled as types (pseudotypes) and eight are apparently lost, leaving a total of 611 types currently deposited at MCZ. From these, 489 represent primary namebearing types (syntype/s, holotype, lectotype and neotype), 21 are probable primary types, and 101 are secondary types (paratype/s, paralectotype/s).
A checklist of 49 damselfly species from 12 families (Odonata: Zygoptera) recorded from Kon Ka Kinh National Park is provided. A first description of the female Protosticta socculus Phan & Kompier, 2016, is given. Burmargiolestes cf. laidlawi Lieftinck, 1960 and three apparently new species, two Coeliccia and one Protosticta species, are recorded, all of which are to be described in the future.
Phnom Tumpor is a scarcely accessible basalt table mountain in the Cardamom Mts. in Pursat Province of Cambodia. On top surface it bears tall evergreen forest (ca 1100 m a.s.l.), concealing a slow rivulet, O'Gran, being a chain of deep pools. It was examined odonatologically on March 1418th, 2019. Six common species were recorded in dry and burnt scrub on the Phnom Tumpor slopes and ten on the forested upper surface at O'Gran, among them Polycanthagyna erythromelas (Selys, 1891) and Macromia sp. cf. pinratani Asahina, 1987 for the first time in Cambodia. The peculiarities of the males of Coeliccia kazukoae Asahina, 1984 from Phnom Tumpor and the problem of distinguishing females of M. pinratani and M. moorei are discussed.
Survey in three protected areas of Chhattisgarh reveals the presence of 50 species of Odonata belonging to 34 genera and 9 families. Specimens were sampled from different lotic and lentic ecosystems. 17 species were exclusively found in or around running water. Larvae or exuviae of 23 species were found and photographed. Habitat availability, larval abundance, species composition and phenology are discussed.
New data on Odonata of the Preah Sihanouk Province of Cambodia obtained in March 2017 and November 2018 are presented. The presence of Onychargia atrocyana Selys, 1865 in Cambodia is confirmed. Twentyone species are added to the known fauna of the Kbal Chhay Waterfall environs, 19 species to that of Ream Peninsula and 4 to that of Koh Rong Island. The total number of species registered for Kampong Saom Peninsula amounts to 74. The presented data are rather of historical importance since most of the remaining forest has been quickly and irreversibly logged a few months ago. The validity of Gynacantha demeter Ris, 1911 as a species distinct from G. dohrnii Krüger, 1899 is doubted.
Globally urban wetlands are under high anthropogenic pressure of degradation. Urban wetlands are hotspots for species losses and rapid turnover in species assemblages. Therefore, studying such wetlands may provide an estimate of the pace of local extinction, concerning wetlanddependent species such as odonates. We undertook a study to document odonate species across a tropical urbanization gradient. We sampled six localities across the gradient across the Mula River that flows through the Pune City, India. We sampled adult odonates using a newly devised Halfcircle Point Count method from September 2016 to March 2017. We took multiple temporal replicates per site. We also sampled larvae across six sites once in November 2016. We measured site characteristics such as canopy cover, solid waste, and water turbidity to understand the level of disturbance at each site. We recorded 41 odonates, six species (primarily Gomphidae members) exclusively from the larval sampling. We did not find the localization of species in a particular site across the urbanization gradient, possibly because we sampled a relatively short stretch of the river to capture the variation. Here, we update the Odonata list of Pune including data on larvae. We demonstrate that larval sampling complements Odonata surveys, especially in recording Gomphids.
We recommend future research to include a longer timespan and extensive sampling area.
The article presents new faunistic data on 33 Odonata species, based on the material collected by the author in 2012, 2016 and 2017 and a systematic research in 2018 throughout the Nakhichevan Autonomous Republic (AR). Onychogomphus assimilis (Schneider, 1845) is a new record for the fauna of Azerbaijan. Eight species were registered for the first time for the territory of Nakhichevan AR: Lestes virens Rambur, 1842, Coenagrion scitulum (Rambur, 1842), Aeshna mixta Latreille, 1805, Anaciaeschna isoceles (Müller, 1764), Anax parthenope (Selys, 1839), Sympetrum sanguineum (Müller, 1764), Crocothemis erythraea (Brullé, 1832), and Selysiothemis nigra (Vander Linden, 1825).
Another survey of Odonata on the Indonesian island of Belitung is reported. This survey was the second survey conducted in the Belitung area with International Dragonfly Fund support and was focused to Belitung Regency's outer islands. Seventy two species were recorded during the survey. Significant records from the surveyed islands include Amphicnemis kuiperi, Mortonagrion arthuri, Mortonagrion appendiculatum, Teinobasis ruficollis, Platylestes heterostylus, Pornothemis serrata, Pornothemis starrei and Tramea phaeoneura. Almost all the records are new to the small islands surveyed, except for Mendanau Island for which there were already records of four species. A checklist of the odonate fauna of the outer islands is given in an appendix.
Contribution to the Odonata fauna of the Society Islands, French Polynesia (Insecta: Odonata)
(2019)
Following field studies in 2018 the Odonata fauna of Society Islands, French Polynesia is reviewed and the validity of all records analysed. An updated species list is provided, bringing the number of breeding species recorded from this island group to ten.
Field studies targeted Hemicordulia Selys, 1870 specimens for inclusion in the revision of the Pacific representatives of the genus. Samples were taken mainly from Tahiti and Raiatea, with some additional specimens collected from Bora Bora and Huahine. Only the Society Islands endemic H. oceanica Selys, 1871 was encountered on all four islands, being recorded from Bora Bora for the first time. At least one new species of Hemicordulia has been reported from the high mountain areas of Tahiti (Jacq et al. 2009, 2014).
The present study also emphasises the need for a revision of Zygoptera records from the French Polynesia and the rest of the Pacific. Presently, about 25 endemic species provisionally assigned to Ischnura Charpentier, 1840 and Hivaagrion Hämäläinen & Marinov, 2014 are known from the Society, Austral and Marquesas island groups (R. Englund, J. Jacq, T. Ramage, D. Polhemus, per. comm.). Only seven of them have been described so far. Detailed morphological and molecular analyses will likely prove the separate generic status of some of the species presently included under Ischnura.
Records of Odonata from Sarawak's Bintulu Division are presented. One hundred and sixtysix (or more) species are listed, of which three (Oligoaeschna amata (Förster, 1903), O. buehri (Förster, 1903) and Oligoaeschna (?) species) had not previously been recorded in Sarawak and Macromia species cf dione Lieftinck, 1971 had not previously been recorded from Borneo. Additionally this is the first published record of Prodasineura tenebricosa Lieftinck, 1937 from Sarawak, although it had been found at another location in the state prior to its discovery in Bintulu, and the first published record of Phyllothemis raymondi Lieftinck, 1950 from Borneo, although specimens from Kalimantan are present in the collections of the Naturalis Biodiversity Center, Leiden. Other notable records include "Elattoneura" longispina Lieftinck, 1937, Pericnemis dowi Orr & Hämäläinen, 2013, Linaeschna polli Martin, 1909, Burmagomphus arthuri Lieftinck, 1953, Heliogomphus borneensis Lieftinck, 1964, Merogomphus femoralis Laidlaw, 1931, Chlorogomphus species, Macromidia genialis erratica Lieftinck, 1948 and Tetrathemis flavescens Kirby, 1889. Altogether there do not appear to be any previous published records from Bintulu Division of 52 of the species listed in this paper. The status of Rhyothemis fulgens Kirby, 1889 is discussed and illustrations of its anal appendages and those of R. pygmaea (Brauer, 1867) are provided. Illustrations of the anal appendages of Tetrathemis hyalina Kirby, 1889 and T. irregularis Brauer, 1868 are also provided. Identification problems when using COIbased DNA barcoding with some species of Archibasis are discussed, and the nuclear marker ITS is shown to be a successful alternative in these cases; COI and ITS gene trees for part of the genus are included. Some COI data for Macromia species are published and the marker is used to identify larvae of M. corycia Laidlaw, 1922 and establish the relationship of another Macromia larva with M. dione, a very poorly known species from Sumatra. Macromia euterpe Laidlaw, 1915 is considered to be the same species as M. westwoodii Selys, 1874 and dropped from the list of species known from Sarawak, however formal combination of the two species is left for a peer reviewed publication. A detailed list of previously unpublished specimens from the locations covered is given in an appendix. Concise checklists for two of the locations covered Similajau National Park (54 species) and the Bukit Mina Wildlife Corridor (84 species) are given in another appendix.
This study investigates the history of Odonata studies in the Republic of Vanuatu and presents results from a two week field sampling mainly on three islands – Efate, Aneityum and Malekula. A total of 32 species are recognised as currently valid names for the country. Three new species have been collected and will be described elsewhere. Various taxonomic, faunistic and biogeographic issues are discussed in the light of the new material collected during the current study in comparison to already published research.
The general conclusion is that provisional species checklist is far from complete. The territory of Vanuatu is still highly insufficiently studied for its Odonata fauna. The local endemic genus Vanuatubasis Ober & Staniczek, 2009 is believed to be far more diverse than currently known with three described and three new species collected during the present study.
The success of social insects is largely intertwined with their highly advanced chemical communication system that facilitates recognition and discrimination of species and nest-mates, recruitment, and division of labor. Hydrocarbons, which cover the cuticle of insects, not only serve as waterproofing agents but also constitute a major component of this communication system. Two cryptic Crematogaster species, which share their nest with Camponotus ants, show striking diversity in their cuticular hydrocarbon (CHC) profile. This mutualistic system therefore offers a great opportunity to study the genetic basis of CHC divergence between sister species. As a basis for further genome-wide studies high-quality genomes are needed. Here, we present the annotated draft genome for Crematogaster levior A. By combining the three most commonly used sequencing techniques—Illumina, PacBio, and Oxford Nanopore—we constructed a high-quality de novo ant genome. We show that even low coverage of long reads can add significantly to overall genome contiguity. Annotation of desaturase and elongase genes, which play a role in CHC biosynthesis revealed one of the largest repertoires in ants and a higher number of desaturases in general than in other Hymenoptera. This may provide a mechanistic explanation for the high diversity observed in C. levior CHC profiles.
Natural history collections are fundamental for biodiversity research as well as for any applied environment-related research. These collections can be seen as archives of earth´s life providing the basis to address highly relevant scientific questions such as how biodiversity changes in certain environments, either through evolutionary processes in a geological timescale, or by man-made transformation of habitats throughout the last decades and/or centuries. A prominent example is the decline of the European flat oyster Ostrea edulis Linneaus, 1758 in the North Sea and the concomitant invasion of the common limpet slipper Crepidula fornicata, which has been implicated to have negative effects on O. edulis. We used collections to analyse population changes in both species in the North Sea. In order to reconstruct the change in distribution and diversity over the past 200 years, we combined the temporal and spatial information recorded with the collected specimens contained in several European natural history collections. Our data recover the decline of O. edulis in the North Sea from the 19th century to the present and the process of invasion of C. fornicata. Importantly, the decline of O. edulis was nearly completed before C. fornicata appeared in the North Sea, suggesting that the latter had nothing to do with the local extinction of O. edulis in the North Sea.
Web spiders connect silk proteins, so-called spidroins, into fibers of extraordinary toughness. The spidroin N-terminal domain (NTD) plays a pivotal role in this process: it polymerizes spidroins through a complex mechanism of dimerization. Here we analyze sequences of spidroin NTDs and find an unusually high content of the amino acid methionine. We simultaneously mutate all methionines present in the hydrophobic core of a spidroin NTD from a nursery web spider’s dragline silk to leucine. The mutated NTD is strongly stabilized and folds at the theoretical speed limit. The structure of the mutant is preserved, yet its ability to dimerize is substantially impaired. We find that side chains of core methionines serve to mobilize the fold, which can thereby access various conformations and adapt the association interface for tight binding. Methionine in a hydrophobic core equips a protein with the capacity to dynamically change shape and thus to optimize its function.
Environmental niche modelling is an acclaimed method for estimating species’ present or future distributions. However, in marine environments the assembly of representative data from reliable and unbiased occurrences is challenging. Here, we aimed to model the environmental niche and distribution of marine, parasitic nematodes from the Pseudoterranova decipiens complex using the software Maxent. The distribution of these potentially zoonotic species is of interest, because they infect the muscle tissue of host species targeted by fisheries. To achieve the best possible model, we used two different approaches. The land distance (LD) model was based on abiotic data, whereas the definitive host distance (DHD) model included species-specific biotic data. To assess whether DHD is a suitable descriptor for Pseudoterranova spp., the niches of the parasites and their respective definitive hosts were analysed using ecospat. The performance of LD and DHD was compared based on the variables’ contribution to the model. The DHD-model clearly outperformed the LD-model. While the LD-model gave an estimate of the parasites’ niches, it only showed the potential distribution. The DHD-model produced an estimate of the species’ realised distribution and indicated that biotic variables can help to improve the modelling of data-poor, marine species.
Mapping biodiversity is the marathon of the 21st Century as an answer to the present extinction crisis. A century in which science is also characterised by large scientific datasets collected through new technologies aiming to fill gaps in our knowledge of species distributions. However, most species records rely on observations that are not linked to specimens, which does not allow verification of species hypotheses by other scientists. Natural history museums form a verifiable source of biodiversity records which were made by taxonomists. Nonetheless, these museums seem to be forgotten by biologists in scientific fields other than taxonomy or systematics. Naturalis Biodiversity Center (NBC) in Leiden is care keeper of large collections of marine organisms, which were sampled in the Northeast Atlantic during the CANCAP and Tyro Mauritania II expeditions (1976–1988). Many octocorals were sampled and deposited in the NBC collection, where they became available for study and were partially identified by the senior author (M.G.) in the 1980s. Nonetheless, no checklist or taxonomic revision was published so far with the complete results. In 2016 the first author visited NBC to examine NE Atlantic Plexauridae octocorals. Plexauridae octocoral-vouchered records were listed and mapped to reveal high standard primary biodiversity records unreported so far for the NE Atlantic Ocean. Twenty-four Plexauridae species with ~ six putative new species to science were discovered and eleven new biogeographical records were made from distinct Macaronesian archipelagos. Finally, new depth range records were found for three species at sea basin level and for eight species at a regional scale.
Archaeological evidence indicates that pig domestication had begun by ∼10,500 y before the present (BP) in the Near East, and mitochondrial DNA (mtDNA) suggests that pigs arrived in Europe alongside farmers ∼8,500 y BP. A few thousand years after the introduction of Near Eastern pigs into Europe, however, their characteristic mtDNA signature disappeared and was replaced by haplotypes associated with European wild boars. This turnover could be accounted for by substantial gene flow from local European wild boars, although it is also possible that European wild boars were domesticated independently without any genetic contribution from the Near East. To test these hypotheses, we obtained mtDNA sequences from 2,099 modern and ancient pig samples and 63 nuclear ancient genomes from Near Eastern and European pigs. Our analyses revealed that European domestic pigs dating from 7,100 to 6,000 y BP possessed both Near Eastern and European nuclear ancestry, while later pigs possessed no more than 4% Near Eastern ancestry, indicating that gene flow from European wild boars resulted in a near-complete disappearance of Near East ancestry. In addition, we demonstrate that a variant at a locus encoding black coat color likely originated in the Near East and persisted in European pigs. Altogether, our results indicate that while pigs were not independently domesticated in Europe, the vast majority of human-mediated selection over the past 5,000 y focused on the genomic fraction derived from the European wild boars, and not on the fraction that was selected by early Neolithic farmers over the first 2,500 y of the domestication process.
Cheilostome Bryozoa Anoteropora latirostris, a colonial marine invertebrate, constructs its skeleton from calcite and aragonite. This study presents firstly correlated multi-scale electron microscopy, micro-computed tomography, electron backscatter diffraction and NanoSIMS mapping. We show that all primary, coarse-grained platy calcitic lateral walls are covered by fine-grained fibrous aragonite. Vertical lateral walls separating autozooid chambers have aragonite only on their distal side. This type of asymmetric mineralization of lateral walls results from the vertical arrangement of the zooids at the growth margins of the colony and represents a type of biomineralization previously unknown in cheilostome bryozoans. NanoSIMS mapping across the aragonite-calcite interface indicates an organic layer between both mineral phases, likely representing an organic template for biomineralization of aragonite on the calcite layer. Analysis of crystallographic orientations show a moderately strong crystallographic preferred orientation (CPO) for calcite (7.4 times random orientation) and an overall weaker CPO for aragonite (2.4 times random orientation) with a high degree of twinning (45%) of the aragonite grains. The calculated Young’s modulus for the CPO map shows a weak mechanical direction perpendicular to the colony’s upper surface facilitating this organism’s strategy of clonal reproduction by fragmentation along the vertical zooid walls.
The present study aims to clarify the confused taxonomy of Z. schaufussi von Frauenfeld, 1862 and Zospeum suarezi Gittenberger, 1980. Revision of Iberian Zospeum micro snails is severely hindered by uncertainties regarding the identity of the oldest Iberian Zospeum species, Z. schaufussi von Frauenfeld, 1862. In this paper, we clarify its taxonomic status by designating a lectotype from the original syntype series and by describing its internal and external shell morphology. Using SEM-EDX, we attempt to identify the area of the type locality cave more precisely than "a cave in Spain". The shell described and illustrated by Gittenberger (1980) as Z. schaufussi appears not to be conspecific with the lectotype shell, and is considered a separate species, Z. gittenbergeri Jochum, Prieto & De Winter, sp. n.
Zospeum suarezi was described from various caves in NW Spain. Study of the type material reveals that these shells are not homogenous in shell morphology. The holotype shell of Z. suarezi is imaged here for the first time. The paratype shell, illustrated by Gittenberger (1980) from a distant, second cave, is described as Zospeum praetermissum Jochum, Prieto & De Winter, sp. n. The shell selected here as lectotype of Z. schaufussi, was also considered a paratype of Z. suarezi by Gittenberger (1980). Since this specimen is morphologically very similar to topotypic shells of Z. suarezi, the latter species is considered a junior synonym of Z. schaufussi (syn. n.). The internal shell morphology of all these taxa is described and illustrated using X-ray Micro Computer Tomography (Micro-CT).
Drebrin (DBN) regulates cytoskeletal functions during neuronal development, and is thought to contribute to structural and functional synaptic changes associated with aging and Alzheimer’s disease. Here we show that DBN coordinates stress signalling with cytoskeletal dynamics, via a mechanism involving kinase ataxia-telangiectasia mutated (ATM). An excess of reactive oxygen species (ROS) stimulates ATM-dependent phosphorylation of DBN at serine-647, which enhances protein stability and accounts for improved stress resilience in dendritic spines. We generated a humanized DBN Caenorhabditis elegans model and show that a phospho-DBN mutant disrupts the protective ATM effect on lifespan under sustained oxidative stress. Our data indicate a master regulatory function of ATM-DBN in integrating cytosolic stress-induced signalling with the dynamics of actin remodelling to provide protection from synapse dysfunction and ROS-triggered reduced lifespan. They further suggest that DBN protein abundance governs actin filament stability to contribute to the consequences of oxidative stress in physiological and pathological conditions.
Background: The invasive temperate mosquito Aedes japonicus japonicus is a potential vector for various infectious diseases and therefore a target of vector control measures. Even though established in Germany, it is unclear whether the species has already reached its full distribution potential. The possible range of the species, its annual population dynamics, the success of vector control measures and future expansions due to climate change still remain poorly understood. While numerous studies on occurrence have been conducted, they used mainly presence data from relatively few locations. In contrast, we used experimental life history data to model the dynamics of a continuous stage-structured population to infer potential seasonal densities and ask whether stable populations are likely to establish over a period of more than one year. In addition, we used climate change models to infer future ranges. Finally, we evaluated the effectiveness of various stage-specific vector control measures.
Results: Aedes j. japonicus has already established stable populations in the southwest and west of Germany. Our models predict a spread of Ae. j. japonicus beyond the currently observed range, but likely not much further eastwards under current climatic conditions. Climate change models, however, will expand this range substantially and higher annual densities can be expected. Applying vector control measures to oviposition, survival of eggs, larvae or adults showed that application of adulticides for 30 days between late spring and early autumn, while ambient temperatures are above 9 °C, can reduce population density by 75%. Continuous application of larvicide showed similar results in population reduction. Most importantly, we showed that with the consequent application of a mixed strategy, it should be possible to significantly reduce or even extinguish existing populations with reasonable effort.
Conclusion: Our study provides valuable insights into the mechanisms concerning the establishment of stable populations in invasive species. In order to minimise the hazard to public health, we recommend vector control measures to be applied in ‘high risk areas’ which are predicted to allow establishment of stable populations to establish.
A world dataset on the geographic distributions of Solenidae razor clams (Mollusca: Bivalvia)
(2019)
Background: Using this dataset, we examined the global geographical distributions of Solenidae species in relation to their endemicity, species richness and latitudinal ranges and then predicted their distributions under future climate change using species distribution modelling techniques (Saeedi et al. 2016a, Saeedi et al. 2016b). We found that the global latitudinal species richness in Solenidae is bi-modal, dipping at the equator most likely derived by high sea surface temperature (Saeedi et al. 2016b). We also found that most of the Solenidae species will shift their distribution ranges polewards due to global warming (Saeedi et al. 2016a). We also provided a comprehensive review of the taxon to test whether the latitudinal gradient in species richness was uni-modal with a peak in the tropics or northern hemisphere or asymmetric and bimodal as proposed previously (Chaudhary et al. 2016).
New information: This paper presents an integrated global geographic distribution dataset for 77 Solenidae taxa, including 3,034 geographic distribution records. This dataset was compiled after a careful data-collection and cleaning procedure over four years. Data were collected using field sampling, literature and from open-access databases. Then all the records went through quality control procedures such as validating the taxonomy of the species by examining and re-identifying the specimens in museum collections and using taxonomic and geographic data quality control tools in the World Register of Marine Species (WoRMS) and the r-OBIS package (Provoost and Bosch 2017). This dataset can thus be further used for taxonomical and biogeographical studies of Solenidae.
The trade in bear parts for medicine and for status is a conservation challenge throughout Asia. The Asiatic black bear (Ursus thibetanus) and the sun bear (Helarctos malayanus) are endemic to this region, and populations are estimated to have declined throughout their ranges due to widespread illegal killing of bears and trade in parts, combined with loss of habitat. Previous studies have indicated that legislation alone is insufficient to prevent illegal hunting and trade, indicating instead a need to address demand for bear parts and products. We conducted mixed-method surveys in Cambodia to understand the key motivators for individuals to consume bear parts, and to understand whether specialised questioning techniques are applicable in this context. Bear part use is illegal in Cambodia and may therefore be considered a sensitive behaviour, in that individuals may be reluctant to admit to it. To counteract possible biases, four specialised questioning techniques were used in this study: randomised response technique (RRT), unmatched count technique (UCT), nominative technique (NT), and false consensus bias (FCB). All four methods serve to shield a respondent’s admittance of a sensitive behaviour from the interviewer. The results presented here show that great variability exists in anonymous methods’ efficacy in certain contexts. However, the results overall indicate that individuals in Cambodia are under-reporting their consumption of bear parts when directly asked, and that the prevalence of bear part use in Cambodia may be as high as 15% of the population, representing a significant conservation challenge.