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1.
A new genus and species, Cryptohelops menaticus gen. et sp. n., are described from the Palaeocene of Menat (France). The new genus belongs to the subtribe Helopina of the tribe Helopini (subfamily Tenebrioninae of Tenebrionidae) based on the coarse and dense punctation of the hypomera, shape of the prosternum and metepisterna, a similar appearance to the native genera Helops and Stenohelops and the structure of the epipleura. The new genus also resembles Raiboscelis and Entomogonus by having the protibiae excised along the base of the inner side. The new genus is the oldest representative of the tribe Helopini. Four species of Helops sensu lato previously described from the Oligocene (H. wetteravicus K. Heyden et L. Heyden, 1865) and Miocene (H. atticus Redtenbacher in Ungern, 1867; H. meissneri Heer, 1847 and H. molassicus Heer, 1883) lack important diagnostic characters and should be regarded as members of the tribe Helopini with uncertain generic attribution.  相似文献   

2.
A taxonomic review of seven species of Diplocheila of the Far East of Russia and adjacent lands is given. Three species are known from the Russian Far East, two of which, D. zeelandica Redt. and D. minima Jedl., are recorded from Russia for the first time. A key to the East Asian species is presented. Composition and diagnoses of subgenera are discussed. The subgenus Submera Habu is restored.  相似文献   

3.
Failure of interspecific androgenesis between brook charr (Salvelinus fontinalis, Mitchill 1814) and Arctic charr (Salvelinus alpinus, L.) has been attributed to the conflict between the egg cytoplasm of one species and the sperm nucleus of the other species. To overcome this incompatibility, sperm derived from the brook charr × Arctic charr hybrid male was used to induce androgenetic development in eggs originating from the parental species as well as their hybrids. The eggs were subjected to 420 Gy of X-radiation to damage the maternal nuclear DNA and inseminated with untreated sperm. Haploid zygotes were exposed to high hydrostatic pressure shock (7000 psi for 4 min), which was applied 420 min after insemination to inhibit the first cell cleavage and recover the diploid state of the zygote. The androgenetic diploid offspring that hatched from the brook charr, the Arctic charr and the hybrids eggs had survival rates of 4.7 ± 0.6%, 1.2 ± 0.4% and 16.8 ± 0.5%, respectively. Drastic mortality among the hatched androgenetic individuals was observed within the first five months of rearing. Cytogenetic analysis of the androgenetic progenies exhibited residues of the irradiated maternal nuclear genome in the form of radiation-induced chromosome fragments in 47% of the specimens that were examined. Interactions between the egg cytoplasm and the sperm nucleus, the low quality of the gametes, the expression of homozygous paternal lethal alleles and the incomplete inactivation of the maternal chromosomes were identified as factors responsible for the large mortality among androgenetic embryos and hatchlings.  相似文献   

4.
A new species Pogonophryne minor sp. n. based on materials of Antarctic expeditions on research vessels Chatyr-Dag and Ob’ to the East Antarctica is described. The type specimens of the new species were caught in the Mawson and Davis seas at depths 420–540 m. The comparison of the new species with two other species of the “marmorata” group of the genus Pogonophryne: P. platypogon Eakin, 1988 and the most closely related P. marmorata Norman, 1938 is provided.  相似文献   

5.
6.
30 Palaearctic species of Hadrodactylus are considered. 2 species-group with 6 subgroups are distinguished. 5 new species from the Eastern Palaearctic Region are described: Hadrodactylus arkit sp. n. (Kyrgyzstan), H. caucasicus sp. n. (Caucasus), H. nitidus sp. n., H. sibiricus sp. n., and H. taigensis sp. n. (Eastern Siberia and Far East of Russia). A new combination and a new synonymy Xenoschesis incarnator Aubert, 1985 (recte Hadrodactylus, comb. n.) = Hadrodactylus fugax almator Aubert, 1996, syn. n. are established. An annotated list of species is given with data on the distribution in Russia and adjacent territories. A key to 30 Palaearctic species is given.  相似文献   

7.
The so-called "species problem" has plagued evolutionary biology since before Darwin's publication of the aptly titled Origin of Species. Many biologists think the problem is just a matter of semantics; others complain that it will not be solved until we have more empirical data. Yet, we don't seem to be able to escape discussing it and teaching seminars about it. In this paper, I briefly examine the main themes of the biological and philosophical literatures on the species problem, focusing on identifying common threads as well as relevant differences. I then argue two fundamental points. First, the species problem is not primarily an empirical one, but it is rather fraught with philosophical questions that require-but cannot be settled by-empirical evidence. Second, the (dis-)solution lies in explicitly adopting Wittgenstein's idea of "family resemblance" or cluster concepts, and to consider species as an example of such concepts. This solution has several attractive features, including bringing together apparently diverging themes of discussion among biologists and philosophers. The current proposal is conceptually independent (though not incompatible) with the pluralist approach to the species problem advocated by Mishler, Donoghue, Kitcher and Dupré, which implies that distinct aspects of the species question need to be emphasized depending on the goals of the researcher. From the biological literature, the concept of species that most closely matches the philosophical discussion presented here is Templeton's cohesion idea.  相似文献   

8.
We describe a new species of Imantodes from the Chocó region of northwestern Ecuador. The new species differs most significantly from all other congeners in lacking a loreal scale. We analyze the phylogenetic relationships among species of Imantodes based on two mitochondrial genes, and postulate that the new species and Imantodes lentiferus are sister taxa. A key to the species of Imantodes from Ecuador is presented.  相似文献   

9.
10.
Ulva (Enteromorpha) prolifera, widely distributed from the intertidal to the upper subtidal zones around the world, was the dominant species of the massive green tides in the Yellow Sea in the summers of 2007, 2008, and 2009. However, little is known about its intra-species genetic diversity. In this study, six attached and seven floating U. prolifera samples collected from different sites distributed from the north of the Yellow Sea to the south of the East China Sea were taken in inter-simple sequence repeat (ISSR) analysis. Based on the results of the 90 polymorphic bands from four ISSR primers, the genetic diversity level of the floating samples (H = 0.1663, I = 0.2608) was found to be lower than that of the attached samples (H = 0.2105, I = 0.3346). Unweighted pair-group mean analysis (UPGMA) and principal coordinate analysis (PCoA) suggested that floating U. prolifera samples in the Yellow Sea from 2007 to 2009 had a close genetic relationship, and the floating samples were separated from the attached samples. Genetic differentiation and limited gene flow among attached U. prolifera populations were indicated by analysis of molecular variance.  相似文献   

11.
Habitat modification and invasive species are significant drivers of biodiversity decline. However, distinguishing between the impacts of these two drivers on native species can be difficult. For example, habitat modification may reduce native species abundance, while an invasive species may take advantage of the new environment. This scenario has been described as the driver‐passenger model, with ‘passengers’ taking advantage of habitat modification and ‘drivers’ causing native species decline. Therefore, research must incorporate both habitat modification and invasive species impact to successfully investigate native species decline. In this paper, we used the common myna (Acridotheres tristis) as a case study to investigate the driver‐passenger model. We investigated changes in bird abundance, over 2 years, in relation to different habitat types and common myna abundance. We hypothesized that the common myna is both a passenger of habitat change and a driver of some bird species decline. Our results indicated that the abundance of many native species is greater in high tree density nature reserves, while the common myna was uncommon in these areas. Common myna abundance was almost three times higher in urban areas than nature reserves and declined rapidly as tree density in nature reserves increased. Our findings indicated that the common myna is primarily a passenger of habitat change. However, we also observed negative associations between common myna abundance and some bird species. We stress the importance of simultaneously investigating both invasive species impact and habitat modification. We suggest habitat restoration could be a useful tool for both native species recovery and invasive species control. Understanding the drivers of native species decline will help inform impact mitigation and direct further research.  相似文献   

12.
Here we describe and illustrate a new parasitoid wasp species, Lathrolestes gauldi sp. n. from the lowland rainforest of eastern Ecuador and provide a key to the Neotropical species of the genus. This is the first record of the subfamily Ctenopelmatinae from Ecuador.  相似文献   

13.
Biotic and abiotic factors such as resource availability and rainfall may exert influence on the life cycle of several organisms. In this study, we investigated correlations between the phenology of hawkmoths, flowering phenology of Inga Mill. species (Fabaceae–Mimosoideae–Ingeae) and rainfall in one of the largest remnants of Atlantic forest in northeastern Brazil (Coimbra forest with ca. 3500 ha). We carried out monthly hawkmoth inventories and phenological observations of the five most abundant Inga species in Coimbra forest from October 2005 to August 2007. Altogether 39 hawkmoth individuals were collected with light trap or butterfly net, which were ascribed to nine genera and 14 species. With the present study Pachygonidia caliginosa Boisduval (Bombycoidea–Sphingidae–Dilophonotina) is registered for the second time in Brazil, since the species had been previously collected only in the Amazon. The tribe Dilophonotina was the most represented with five species. Animals with short proboscises (14.7–35.0 mm) represented over 69.7% of the sample. Most individuals were collected during the months of low rainfall, the same period of the highest flower abundance of five Inga species. The flowering of Inga vera, I. striata and I. ingoides was positively correlated with hawkmoth abundance. The synchrony of the activity period of these animals in adult phase with certain nectar sources, and the relationship between morphological parameters of hawkmoths and Inga flowers suggest a narrow pollination mutualistic relationship at the study site. Considering the hotspot status of the Atlantic forest due to high fragmentation and habitat loss, as well as the previous local extinction of hawkmoth species in smaller fragments of the studied landscape, our results are relevant for restoration plans not only for the Brazilian Atlantic forest, but for neotropical forests in general, where Inga is native.  相似文献   

14.
Biological Invasions - Biological invasions are increasing worldwide, damaging ecosystems and socioeconomic sectors. Two decades ago, the “100 of the world’s worst” invasive alien...  相似文献   

15.
Paraportanus longispinus,, a new leafhopper species from Roraima and Amazonas States, North Brazil, is described and illustrated. The new species can be recognized by the male genital features, especially the distal third of ventral margin of the pygofer with a dentiform short process; plates distinctly longer than pygofer, extending posteriorly beyond pygofer by approximately 1/3 of their length and aedeagus with one pair of spiniform process long crossed and directed ventrally. A checklist and key to males of all known Paraportanus species is provided.  相似文献   

16.
Allozyme electrophoresis was used to measure levels and distribution of genetic diversity in the critically endangered (CR) Silene sennenii (Caryophyllaceae), a narrow endemic plant species found in northeastern Catalonia (Spain). At present, only 5 populations remain, containing no more than 5,000 individuals, which are subjected to several human pressures such as habitat fragmentation and land use changes. Interestingly, the largest population is located in and around a fortress built in the XVIII century, a circumstance which might facilitated its preservation until now. From the 21 satisfactorily interpreted loci, low levels of genetic variation were detected (P = 20.9, A = 1.31 and H e = 0.071), which may be related to small population size, isolation, and fragmentation of extant populations. Moderate to high levels of inbreeding were also found, probably as consequence of the population’s genetic structuring. The conservation of the population located in the fortress would allow the preservation of all the alleles detected at species level; nevertheless, conservation of other populations, coupled with the inclusion of S. sennenii in the Spanish Catalogue of Endangered Species, would also be desirable in order to ensure the long-term survival of the species.  相似文献   

17.
The genus Taraxacum is characterized by prevailing complex multiple hybridity, frequent polyploidy and widespread agamospermous reproduction, which makes the phylogenetic analysis difficult. On the basis of the previous analysis of the variation of nrDNA in Taraxacum taxa with different ploidy levels and modes of reproduction, to mitigate consequences of the reticulate complexity of the genus, a phylogenetic study of 52 samples of sexually reproducing dandelions of 26 sections (and another 13 agamospermous representatives of other sections known to include sexuals) was carried out. Both sexual and agamospermous samples were analysed using maximum parsimony and neighbour network. Exclusively sexual dandelions were analysed using the same approaches. In spite of the general agreement among various types of analyses, there is a limited overall congruence between results of nrDNA analyses and the established taxonomic system of the genus Taraxacum. The analyses shed light on the relationships among the most primitive groups. A stable clade is formed by representatives of the sections Primigenia, Orientalia, Sonchidium, Piesis and T. cylleneum. Another case of stable relationships is that of the members of the sect. Dioszegia. Relationships between the sects. Erythrosperma and Erythrocarpa were supported, and the relatedness of the members of sect. Australasica was confirmed. Rather unexpectedly, the agamospermous samples of the sect. Oligantha (T. minutilobum) are shown to be closely related with the sect. Macrocornuta. The latter section is generally considered to be close to sect. Ceratoidea (T. koksaghyz) on morphological grounds but this presumption is not corroborated by the results of nrDNA analyses. Analyses of 72 samples of sexual dandelions were also performed using the trnL–trnF region of the chloroplast DNA. The maximum parsimony analysis of this region reveals intraspecific variation in a number of ancestral diploid sexual species, all present in the two main branches of the cladogram. This phenomenon is attributed to the ancient gene flow and possibly to the persistence of ancestral cpDNA polymorphism. The strict consensus cpDNA tree information content and interpretability is quite low. The maximum parsimony analysis of combined nrDNA and cpDNA data sets was also performed with expectably low interpretability of the results.  相似文献   

18.
34 Palaearctic species of Rhorus are considered, 9 groups of species are distinguished, and 24 new species from the Eastern Palaearctic (mainly from the Russian Far East) and one new species reared in St. Petersburg from Phyllocolpa leucosticta are described. A key to all these species is given.  相似文献   

19.
20.
Catalase–peroxidases (KatGs) have two peroxidase-like domains. The N-terminal domain contains the heme-dependent, bifunctional active site. Though the C-terminal domain lacks the ability to bind heme or directly catalyze any reaction, it has been proposed to serve as a platform to direct the folding of the N-terminal domain. Toward such a purpose, its I′-helix is highly conserved and appears at the interface between the two domains. Single and multiple substitution variants targeting highly conserved residues of the I′-helix were generated for intact KatG as well as the stand-alone C-terminal domain (KatGC). Single variants of intact KatG produced only subtle variations in spectroscopic and catalytic properties of the enzyme. However, the double and quadruple variants showed substantial increases in hexa-coordinate low-spin heme and diminished enzyme activity, similar to that observed for the N-terminal domain on its own (KatGN). The analogous variants of KatGC showed a much more profound loss of function as evaluated by their ability to return KatGN to its active conformation. All of the single variants showed a substantial decrease in the rate and extent of KatGN reactivation, but with two substitutions, KatGC completely lost its capacity for the reactivation of KatGN. These results suggest that the I′-helix is central to direct structural adjustments in the adjacent N-terminal domain and supports the hypothesis that the C-terminal domain serves as a platform to direct N-terminal domain conformation and bifunctionality.  相似文献   

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