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The thermoregulatory behavior of the wavy turban snail Megastrea (Lithopoma) undosa was determined in a horizontal thermal gradient and was 16.31 in day cycle and 14.4 °C in night cycle. Displacement velocity of adults was 29.3±4.2 cm h−1 during the light phase and 26.1±3.2 cm h−1 during the dark phase. The critical thermal maxima of the wavy turban snail were determined. As a measure of thermal tolerance, snails were subjected to increasing water temperatures at a rate of 1 °C every 30 min until they were detached from the substrate. The critical thermal maximum at 50% was 29.7 °C.  相似文献   

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Parmeliaceae is the largest family of lichen-forming fungi. In spite of its importance for fungal diversity, its relationships with other families in Lecanorales remain poorly known. To better understand the evolutionary history of the diversification of lineages and species richness in Parmeliaceae it is important to know the phylogenetic relationships of the closest relatives of the family. A recent study based on two molecular loci suggested that either Protoparmelia s. str. or a group consisting of Gypsoplaca and Protoparmelia s. str. were the possible sister-group candidates of Parmeliaceae, but that study could not distinguish between these two alternatives. Here, we used a four-locus phylogeny (nuLSU, ITS, RPB1, MCM7) to reveal relationships of Parmeliaceae with other potential relatives in Lecanorales. Maximum likelihood and Bayesian analyses showed that Protoparmelia is polyphyletic, with Protoparmelia s. str. (including Protoparmelia badia and Protoparmelia picea) being most closely related to Parmeliaceae s. str., while the Protoparmelia atriseda-group formed the sister-group to Miriquidica. Gypsoplaca formed the sister-group to the Parmeliaceae s. str. + Protoparmelia s. str. clade. Monophyly of Protoparmelia as currently circumscribed, and Gypsoplaca as sister-group to Parmeliaceae s. str. were both significantly rejected by alternative hypothesis testing.  相似文献   

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Taxonomy of 57 bivalves, internal and external molds is described in this paper, corresponding to three paleotaxodontids genera Praectenodonta, Praenucula and Notonucula. Samples were collected from nine sites, where stratigraphic columns were measured in Silurian to Devonian series from Altiplano, Cordillera Oriental and Interandean of Bolivia. For the first time in Bolivia, Praectenodonta and Notonucula have been identified. Four species have been described, three of them are new: Praectenodonta boliviensis n. sp., Praenucula quichua n. sp. and Notonucula altiplanica n. sp. Paleogeography of new species and genera is proposed.  相似文献   

8.
The section Brunnei was extensively studied based on material from North Europe. To stabilise the nomenclature we studied the relevant types of taxa included in this section. Phylogenetic relationships and species limits were investigated using rDNA ITS sequences and the results were compared with the morphological data. We recognised 11 species: Cortinarius brunneus, C. clarobrunneus comb. nov., C. coleoptera, C. ectypus, C. gentilis, C. glandicolor (neotypified), C. pseudorubricosus, and four species described as new C. caesiobrunneus, C. albogaudis, C. carabus, and C. cicindela. They are described here and their taxonomy, ecology, distribution, and relationships are discussed. In addition, a key to species of the section Brunnei is provided. A total of 77 new sequences of 11 species are published including nine type sequences. Also the taxonomic assignments of sequences in the public databases belonging to the section Brunnei are revised.  相似文献   

9.
It has been extensively documented that exposure of amphibians and teleost fish to exogenous steroid hormones like estrogen, androgen, xenoestrogen or steroid biosynthesis inhibitors can impair their gonadal development or induce sex reversal against genotypic sex. However, the molecular pathways underlying sexual development and the effects of sex steroids or other exogenous hormones in these aquatic vertebrates remain elusive. Recently, a germ plasm-associated piRNA (piwi-interacting RNA) pathway has been shown to be a determinant in the development of animal gonadal germline cells. In the current study, we examined whether this piRNA pathway is involved in the regulation of sex steroid hormones in gonadal development. We firstly established developmental expression patterns of three key piRNA pathway genes (mael, piwi and vasa), during Silurana (Xenopus) tropicalis embryogenesis and early larval development. All three genes exhibit high expression at early developmental stages and have significantly decreased expression thereafter, indicating a very active involvement of piRNA pathway at the beginning of embryogenesis. We further examined gene expression changes of those genes in frog larvae exposed to two sex steroid biosynthesis inhibitors, fadrozole and finasteride, both of which are known to result in male-biased or female-biased phenotypes, respectively. We found that fadrozole and finasteride exposures increased the expression of piRNA pathway genes such as mael and vasa at the larval stage when the expression of piRNA pathway genes is programmed to be very low. Therefore, our results indicate that the piRNA pathway is likely a common pathway by which different sex steroid hormones regulate gonadal sex differentiation.  相似文献   

10.
In the temporary carboniferous hall of „GONDWANA - Das Prähistorium“ in Germany, whip spiders (Damon variegatus) were kept and bred. 3,3 were purchased from a dealer in summer 2007. The night active spiders were kept together in a terrarium. No aggresions were observed. The animals were fed little locusts, young hissing cockroaches, and crickets. In 2008 courtship display and mating could be observed. The biggest male was the only active one. After 7 days after the intake of the spermatophores all females carried eggsacs under the ophistosoma. Each egg sack contained approximately 25-30 eggs. During the carrying phase only one female feasted on a cricket. 98 days after the egg sack was produced the young spiderlings hatched. The coloration of the spiderlings was completely different from the coloration of the adults. The spiderlings were carried by the female for the next 9 days. Then, the spiderlings moulted and left the female immediately. The adults were now separated from their young. The three groups of spiderlings stayed together in a smaller terrarium. However, each group from each female stayed separate from the others for weeks. The second moulting took place 41 days after the first one. No cannibalism was observed. Obviously Damon variegatus seems to be a spider with a social touch. If the terrarium and the climate conditions inside are adapted to the needs of the whip spiders keeping and breeding is possible. The species is highly attractive to visitors.  相似文献   

11.
There were distinct ecotypie differences in the ability to develop to third stage larvae at a constant 11 or 13°C for two weeks. H. conforms cayugensis could develop at both 11 and 13°C; H. contortus from Louisiana could develop at 13°C but not 11°C and H. placei could not complete development at either temperature. Eggs produced from the first cross between ecotypes had the same cold tolerance as their maternal parent. F1 eggs were intermediate between parental ecotypes, while F2 eggs, when fertile, developed at the same temperature as the most cold-tolerant parent in the first cross. The H. placei knobbed vulvar morph type was dominant to H. contortus cayugensis smooth morph type and recessive to the H. contortus (Louisiana) smooth morph type. Knobbed morph type of H. contortus (Louisiana) was dominant to smooth of H. contortus cayugensis. Dominance of morph type was enhanced by a matroclinous effect in the between species matings but not in the within species matings. No fertile eggs were produced by the F1 of the mating between female H. placei × male H. contortus (Louisiana) or by the F2 of the reciprocal mating. Reciprocal matings between H. placei × H. contortus cayugensis produced an F1 and F2 that had reduced fertility but were not completely sterile. No decrease in fertility was observed in the F2 and F1 from the H. contortus cayugensis × H. contortus(Louisiana)matings. Cytological studies revealed several kinds of meiotic disturbances in the between species F1 and F2. The most frequent were aneuploidy, failure of chromosome pairing, and pairing between non-homologous chromosomes. Males were more seriously affected than females by meiotic disturbances. The H. placei X chromosome appeared to be selected against by the hybrid genetic background. Within species hybrids showed no meiotic disturbances and the percentage of male offspring from these crosses was the same as for female offspring.  相似文献   

12.
Two isomers (R,S,R,S- and R,R,S,S-) of five coordinate complex [Cu(L)Cl]+ have been separated and characterised. These two isomers have significantly different spectrochemical and electrochemical properties. Absorption maximum of R,S,R,S-[Cu(L)Cl]+ shifts to longer wavelength and its reduction potential shifts to more positive direction comparing those of R,R,S,S-[Cu(L)Cl]+. R,S,R,S-[Cu(L)Cl]+ is significantly distorted to trigonal-bipyramidal structure, whereas R,R,S,S-[Cu(L)Cl]+ retains almost square-planar geometry. The average bond distance of Cu-N in basal plane of R,S,R,S-[Cu(L)Cl]+ is longer by 0.024 Å than that of R,R,S,S-[Cu(L)Cl]+, whereas the bond distance of Cu-Cl in former is shorter by 0.200 Å than that in latter. The isolated square-planar complexes of R,R,S,S- and R,S,R,S-[Cu(L)](ClO4)2 are converted to the R,R,S,S- and R,S,R,S-[Cu(L)Cl]+ by the addition of Cl in nitromethane solution with the rate constants, k=1.70 (±0.02) and 8.31 (±0.07) M−1 s−1, respectively.  相似文献   

13.
Torrubiella is a genus of arthropod-pathogenic fungi that primarily attacks spiders and scale insects. Based on the morphology of the perithecia, asci, and ascospores, it is classified in Clavicipitaceae s. lat. (Hypocreales), and is considered a close relative of Cordyceps s. 1., which was recently reclassified into three families (Clavicipitaceae s. str., Cordycipitaceae, Ophiocordycipitaceae) and four genera (Cordyceps s. str, Elaphocordyceps, Metacordyceps, and Ophiocordyceps). Torrubiella is distinguished morphologically from Cordyceps s. lat. mainly by the production of superficial perithecia and the absence of a well-developed stipitate stroma. To test and refine evolutionary hypotheses regarding the placement of Torrubiella and its relationship to Cordyceps s. lat., a multi-gene phylogeny was constructed by conducting ML and Bayesian analyses. The monophyly of Torrubiella was rejected by these analyses with species of the genus present in Clavicipitaceae, Cordycipitaceae, and Ophiocordycipitaceae, and often intermixed among species of Cordyceps s. lat. The morphological characters traditionally used to define the genus are, therefore, not phylogenetically informative, with the stipitate stromata being gained and/or lost several times among clavicipitaceous fungi. Two new genera (Conoideocrella, Orbiocrella) are proposed to accommodate two separate lineages of torrubielloid fungi in the Clavicipitaceae s. str. In addition, one species is reclassified in Cordyceps s. str. and three are reclassified in Ophiocordyceps. The phylogenetic importance of anamorphic genera, host affiliation, and stipitate stromata is discussed.  相似文献   

14.
The novel ciliate Platynematum salinarum (Scuticociliatia) was isolated only recently from a thalassohaline solar saltern pond (12%) in Portugal. Scanning electron microscopy showed numerous bacterial-shaped cells covering the complete surface of the ciliate. The rod-shaped epibionts were identified and characterized following the “Full-Cycle rRNA Approach”. The almost full-length 16S rRNA gene sequence was obtained using archaeal-specific primers and two species-specific probes were designed for fluorescence in situ hybridization. The 16S rRNA gene sequence of the epibiotic cells showed 87% sequence identity with the type strain sequence of the closest characterized species Halolamina pelagica. Phylogenetic reconstructions affiliated the novel organism to the genus Halolamina (Halobacteria, Archaea). Attempts to isolate the epibionts failed and, therefore, growth experiments incorporating the antibiotic anisomycin were conducted in order to investigate the potential symbiotic relationship between P. salinarum and the epibionts. The results suggested an obligate symbiosis between the two organisms and revealed the first symbiotic representative of the Halobacteria. Based on the phylogenetic analyses and growth experiments we propose the classification of this novel organism in a new genus, with the taxon name “Candidatus Haloectosymbiotes riaformosensis”.  相似文献   

15.
In the lignite sediments of Pietrafitta (Tiberino Basin, Umbria, Central Italy), a rich fossil assemblage of vertebrate, invertebrate and plant remains belonging to the Farneta Faunal Unit (Late Villafranchian, Early Pleistocene) was collected. Among them fossil beaver cranial remains are relatively abundant. Western-Central Europe Villafranchian beaver remains were assigned to C. plicidens by some authors because molar occlusal surface patterns show complex enamel crenulations. Several recent authors have classified them as C. fiber while analysing other morphological patterns. Our samples have been compared to Plio-Pleistocene fossil remains and to living European populations of the genus Castor. New morphometric parameters on molar occlusal surfaces have been defined and statistical analyses (One-Way MANOVA, Principal Component Analysis and Canonical Discriminant Analysis) have been performed on them. The results point out a subspecific separation between the Late Villafranchian beaver of Pietrafitta, Quarata and San Giovanni in Valdarno (Umbria and Tuscany) and C. fiber populations. St. Vallier (France) Late Pliocene and Mosbach 2 (Germany) Middle Pleistocene beavers classified respectively by Viret and Friant as C. plicidens, show a C. f. fiber molar teeth pattern. Therefore, C. fiber plicidens did not occur in Central-Western Europe and this subspecific name may be used only for the local populations of Valdarno and Tiberino Basin (San Giovanni in Valdarno, Quarata, Pietrafitta and a few localities of the same area), at that time peripheral populations, probably semi-isolated during the Late Villafranchian, and at the southern limit of the geographic range of C. fiber.  相似文献   

16.
Ambrosia beetles (Coleoptera: Scolytinae) are associated with strictly entomochoric and mutualistic fungi. We studied the mycobiota associated with Scolytodes unipunctatus, ambrosia beetles that infest Cecropia trees in Central America. Isolates were characterized using morphology and rDNA sequences (ITS region, LSU, and SSU rDNA). Four species are described here: Raffaelea scolytodis sp. nov. (Ophiostomatales), Gondwanamyces scolytodis sp. nov., Custingophora cecropiae sp. nov., and Graphium sp. (Microascales). The genus Custingophora is emended to include Knoxdaviesia anamorphs of Gondwanamyces based on uniformity of DNA sequences and phenotype.  相似文献   

17.
The reactions of [PtMe3(OAc)(bpy)] (4) with the N,S and S,S containing heterocycles, pyrimidine-2-thione (pymtH), pyridine-2-thione (pytH), thiazoline-2-thione (tztH) and thiophene-2-thiol (tptH), resulted in the formation of the monomeric complexes [PtMe3(-κS)(bpy)] ( = pymt, 5; pyt, 6; tzt, 7; tpt, 8), where the heterocyclic ligand is coordinated via the exocyclic sulfur atom. In contrast, in the reactions of [PtMe3(OAc)(Me2CO)x] (3, x = 1 or 2) with pymtH, pytH, tztH and tptH dimeric complexes [{PtMe3(μ-)}2] (μ- = pymt, 9; pyt, 10; tzt, 11) and the tetrameric complex [{PtMe33-tpt-κS)}4] (12), respectively, were formed. The complexes were characterized by microanalyses, 1H and 13C NMR spectroscopy and negative ESI-MS (12) measurements. Single-crystal X-ray diffraction analysis of [PtMe3(pymt-κS)(bpy)] (5) exhibited a conformation where the pymt ligand lies nearly perpendicular to the complex plane above the bpy ligand that was also confirmed by quantum chemical calculations on the DFT level of theory.  相似文献   

18.
The detailed study of a sample of “Pecten (Amussiopecten) benoisti” Cossmann and Peyrot (1914) from the Chattian outcrops of the Adour Basin, allowed to improve our knowledge of this species poorly known till now and to show its important ornamental variability. It follows that some nomenclatural points have been clarified at the generic level: we refute the attribution of this species to the genus Amussiopecten Sacco (1897) as used by authors—genus which was besides emended several times subsequently— and we propose its allocation to Cristatopecten nov. gen. Furthermore, this study allowed to remove the ambiguity existing originally as for the attribution of the species benoisti and burdigalensis to a same genus: our comparison of the latter two taxa shows that if benoisti has to be henceforth included in the new genus Cristatopecten (as its type species), burdigalensis (which is the type species of Amussiopecten) must be incorporated in the genus Flabellipecten Sacco (1897). The two genera Amussiopecten and Flabellipecten are therefore synonymous, as Depéret and Roman had already stated in 1910. The Cristatopecten from the Old World seem to be derived from a group of “Aequipecten” notably known in the Italian Rupelian, the group of “Aequipecten deletus” (Michelotti, 1861), of which we study here a sample from the Aquitaine Chattian. In the Aquitaine Basin, the Cristatopecten are represented, in the Chattian, by Cristatopecten benoisti (Cossmann and Peyrot, 1914); in the Lower Aquitanian, by C. praehaueri (Bongrain, Cahuzac and Freneix, 1994); in the Burdigalian-Langhian of the Saubrigues paleocanyon, by C. haueri (Michelotti, 1847) and C. miogallicus (Cossmann and Peyrot, 1914). During the whole Neogene, they spread and evolved in the Tethys and the Paratethys areas, and seem to have become extinct in the Pliocene with the disappearance of C. cristatus (Bronn, 1827), a species that we consider not as an Amusium s.s., but as the last representative of the Cristatopecten phylum.  相似文献   

19.
The new subgenus of Equus, Sussemionus, is defined by peculiar dental characters so far unknown, or exceptional in late Pleistocene and extant Equus; it was in consequence assumed to be restricted to the early and middle Pleistocene. During that period, it was highly successful, ranging from North America to Ethiopia, and included dry-adapted (E. granatensis-like) and more humid-adapted (E. coliemensis-like) species. Recent molecular and osteological analyses concurred to prove its survival until ca 45 KYBP in Khakassia, southwest Siberia, Russia.  相似文献   

20.
Cibicidoides dispars and Cibicidoides variabilis are two neritic cibicidids commonly found on the Patagonian coasts. Phylogenetic analyses of partial SSU rDNA sequences show that they both belong to the genus Cibicidoides. Cibicidoides dispars branches close to Cibicidoides wuellerstorfi, whereas C. variabilis clusters with Cibicidoides pachyderma. In both cases, species clustering together are well separated morphologically and ecologically but close genetically. Molecular data indicate clearly that C. dispars and C. variabilis are well separated genetically from Cibicidoides lobatulus, another shallow water cibicidid sharing a similar ecology and morphology. Moreover, our molecular results show that neritic and bathyal or abyssal species are found together in different clades, suggesting multiple colonization events from shallow to deep water or vice versa. The analysis of more variable ITS rDNA region, on the other hand, reveals small differences between individuals of C. variabilis sampled in the south and north of Chilean Patagonia, which could indicate a cryptic speciation undergoing in this species.  相似文献   

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