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1.
Morphological and molecular studies on a tardigrade species have been carried out to verify the possibility of using a DNA barcoding approach for species identification in this phylum. Macrobiotus macrocalix Bertolani & Rebecchi, 1993 was chosen as the test species since it belongs to a group of species in which the taxonomy is quite problematic. Animals and eggs belonging to three Italian and one Swedish populations have been investigated. Both morphological and molecular analyses show that all the populations belong to the same species. The low genetic distances recorded among the studied populations (0.3-1.0%) and the high genetic distance (15.9-16.3%) between these populations and a closely related species confirm the possibility of identifying a specimen of this species by its cytochrome oxidase subunit I sequence. Data from other authors support our results indicating that DNA barcoding can be applied to tardigrades. With our protocols, we have obtained voucher specimens that enable us to show a correspondence between morphology and molecular data.  相似文献   

2.
The genital anatomy of Orcula jetschini (Romania), Orcula zilchi (Bulgaria), and Orcula wagneri (Albania) is described. Based on anatomical features (morphology of the penial caecum) shell characters (sculpture and shape) and unpublished molecular data the genus Orcula is subdivided into three subgenera. Orcula zilchi was classified within the monotypic subgenus Orcula (Hausdorfia) subgen. n.; Orcula jetschini, Orcula wagneri, and Orcula schmidtii were classified to Orcula (Illyriobanatica) subgen. n. (type species: Pupa schmidtii) whereas the other Orcula species remain in the nominotypical subgenus. Orcula (Hausdorfia) is known from South-Eastern Bulgaria and North-Western Turkey, Orcula (Illyriobanatica) inhabits Western Romania, North-Western Greece, Albania, Macedonia, Kosovo, and Montenegro. The nine species of Orcula (Orcula) are known mainly from the Alps and the Western Carpathians (from Eastern France to Eastern Hungary and Slovakia).The occurrence of only one Orcula species namely Orcula jetschini is verified from Romania. Available information suggests that data on the Romanian occurrence of Orcula dolium and Orcula gularis were based on wrongly identified specimens. Sphyradium dobrogicum (=Orcula dobrogica) is considered as a synonym of Sphyradium doliolum.  相似文献   

3.
Tarsal claws, which are common attachment devices in arthropods, interlock with the surface irregularities of the substrata. Most insects have two tarsal claws, but the larvae of some aquatic insects, such as Ephemeroptera and Trichoptera, bear only one claw on their tarsi. The range of surface roughness that is sufficient for the function of the single claws of aquatic invertebrates has not yet been investigated. In the present study, we investigated the surface texture required for the function of the claws of larvae of the mayfly, Epeorus assimilis. We conducted attachment experiments using replications with defined surface roughness, white light profilometry, videotaping and scanning electron microscopy. The results demonstrate that the choice of an appropriate roughness order is very important. A setting resulting in a cut-off length of approximately thirty times the diameter of the claw tip proved most appropriate for describing the roughness order that is relevant for the functioning of the claws of E. assimilis larvae. Common technical roughness parameters such as Ra, Rq or Rz supplied sufficient differentiation between the tested substrata. E. assimilis larvae require a minimum surface roughness (Ra  6.0 μm) for their claws to grip. At lesser surface roughness, the larvae left the substratum. This was surprising because E. assimilis larvae have been observed to attach even to smooth surfaces. Based on the use of sterile substrata in this experiment, we assume that coverage with biofilm considerably influences the attachment of the larvae.  相似文献   

4.
Polyamines (putrescine, spermidine and spermine) cause a marked increase in the activity of the loach Misgurnus fossilis DNA polymerase α on activated (gapped) DNA. The stimulatory effect increases in the order: putrescine, spermidine, spermine. Kinetic analysis shows that spermine does not change the affinity of the polymerase for dTTP, but it decreases the enzyme affinity for DNA. The apparent Km of the polymerase for activated DNA progressively increases from 14 to 1200 μM (nucleotide), if the concentration of spermine rises up to 2 mM, while Vmax reaches a maximum at 0.5 mM spermine and then drops at higher polyamine concentrations. Native calf thymus DNA and especially single-stranded DNA from phage M13 appear to be inhibitors of α-polymerase activity on gapped DNA. Dixon plots suggest simple competitive inhibition of the polymerase activity by single- or double-stranded DNA and absence of cooperativity in the interaction of the polymerase with DNA. Hill-plot analysis is compatible with the interpretation that there is only one DNA binding site on each DNA polymerase α molecule. Spermine, even at low concentrations, decreases sharply the affinity of the enzyme for double-stranded DNA, while the enzyme affinity for single-stranded DNA changes insignificantly. Another result of spermine action is the destabilization of the polymerase-DNA complex. The ratio of the ‘static affinity’ of the enzyme to its ‘kinetic affinity’ decreases 2.2-fold in the presence of 0.5 mM spermine. As a result, the sensitivity of DNA synthesis to 3′-deoxy-3′-aminothymidine 5′-triphosphate and to 1-β-d-arabinofuranosylcytidine 5′-triphosphate decreases in the presence of the polyamine. Both spermine effects, the decrease in the ‘nonproductive binding’ of the polymerase to double-stranded regions in DNA and the destabilization of the polymerase-DNA complex, presumably account for the increase in the activity of the loach α-polymerase on activated DNA.  相似文献   

5.
Neocarus proteus sp. n., is described from caves and the surrounding epigean environment of ferruginous outcrops (Cangas) in Minas Gerais, Brazil. In addition, some notes about development in this species are presented. Neocarus proteus is the only species in the genus that has smooth or barbed genital setae and that carries coronidia on the basitarsi, tibiae and genua of legs II–III. Females carry additional setae with rounded tips on the subcapitulum, and are, on average, larger than males. This distinct sexual dimorphism appears in the tritonymphal instar and is maintained in the adults.  相似文献   

6.
An important programme of biomonitoring along the coast of Algeciras Bay (Straits of Gibraltar) has allowed us tentatively to consider six species of boring sponges of the genus Cliona as biological indicators: Cliona celata, C. viridis, C. rhodensis, C. vermifera, C. schmidti and C. vastifica. The taxonomy and distribution of these species have been considered in this paper. Ecological observations have permitted us to identify some important characteristics of their habitat on the basis of local environmental parameters. Cliona viridis and C. celata withstand sedimentation higher than 7 gr/m2 and a solid suspension of 38 mg/1. Cliona vermifera and C. schmidti did not tolerate sedimentation higher than 1 gr/m2. One of these, C. vermifera Hancock, is recorded for the first time in the Iberian Peninsula.  相似文献   

7.
《Palaeoworld》2016,25(4):639-646
Additional specimens of rhynchonellide brachiopods from the marly limestones in the Yidade Formation at the Panxi section in eastern Yunnan have been ascribed to the species “Paurorhynchasquamosa Wang, 1956 and “P.depressa Wang, 1956. The two species have been used frequently as index fossils for the Frasnian (Upper Devonian), but their taxonomic assignments are problematic because their internal structures remain unknown. In this study, detailed systematical examinations on both external characters and internal structures revealed by serial sections suggest that the two species are more appropriately assigned to the genus Hadrotatorhynchus Sartenaer, 1986. Based on the stratigraphical distributions of Hadrotatorhynchus and the conodonts in the upper unit of the Yidade Formation, the Hadrotatorhynchus-bearing horizons are re-considered as the uppermost Givetian (Middle Devonian) rather than Frasnian stage, although the precise position of the Middle/Upper Devonian boundary still depends on further investigations of high-resolution biostratigraphy.  相似文献   

8.
9.
13 new species of Ctenochira (Hymenoptera, Ichneumonidae, Tryphoninae) from the Eurasian Subarctic subzone and Siberia are described: C. albosignata sp. n., C. anabar sp. n., C. epipleuralis sp. n., C. gracilicornis sp. n., C. hyperborea sp. n., C. kerzhneri sp. n., C. laticauda sp. n., C. minuta sp. n., C. nigronitens sp. n., C. pallistigma sp. n., C. tixi sp. n., C. trochanterata sp. n., and C. uzon sp. n. A key to the Subarctic and northern Siberian species is given. Quantitative occurrence of different ichneumonid subfamilies in the Subarctic subzone is considered based on analysis of 827 specimens of ichneumonids collected in yellow plates in the Chukchi Autonomous Area in July 2012. Idiobiont (polyphagous) subfamilies (36.5%): Cryptinae, 294 spms. (35.5%); Pimplinae, 8 (1%). Koinobiont parasitoids, 10 subfamilies (63.5%): parasitoids of Symphyta, 313 spms. (37.9%): Tryphoninae, 225 (27.2%); Adelognathinae, 14 (1.7%); Ctenopelmatinae, 59 (7.2%); Campopleginae (Olesicampe; Lathrostizus), 15 (1.8%); parasitoids of Diptera, 169 spms. (20.5%): Diplazontinae, 8 (1%); Orthocentrinae s. l., 161 (19.5%); parasitoids of Lepidoptera, 29 spms. (3.5%): Campopleginae (part), 18 (2.2%) (Campoletis; Hyposoter; Tranosema; Diadegma; etc.); Ichneumoninae, 2 (0.2%); Banchinae, 3 (0.4%) (Glypta; Lissonota); Metopiinae, 6 (0.7%) (Exochus); parasitoids of Coleoptera (0.3%): Tersilochinae, 3 spms. (Barycnemis); hyperparasitoids (1.3%): Mesochorinae, 11 spms.  相似文献   

10.
11.
Climate change poses an unprecedented threat to biodiversity worldwide. Consequently, unrecognised taxa may not receive adequate conservation attention to survive. We used molecular and morphological data to address the challenge of species delimitation within the genus Schilbe. The presence or absence of an adipose fin and distribution based on east-flowing, conceivably faster-flowing, or west-flowing, probably more slow-flowing, river systems were considered. Distinctive geographic patterns in genetic variation within southern, eastern, and western African populations were revealed. Particularly, the South African population is distinct from those of Namibia, Botswana and Nigeria. No individuals with rudimentary adipose fins were found at any locality, but specimens from three localities either had or did not have adipose fins. These mixed occurrences are suspected to be a result of human interventions, and that the presence of rudimentary adipose fins in the east African species could be an adaptive feature that serves to stabilise these fish in faster currents. In addition, the genetic divergence observed among African silver catfish from geographically isolated river systems is conceivably the result of micro-evolutionary adaptive responses to different environmental conditions. Collectively, these results distinguish S. depressirostris from S. intermedius.  相似文献   

12.
The genus Xenophora comprises species of marine gastropods (Cretaceous-Recent) able to add fragments of various origins to their shell surface. Agglutination potentials vary, from species lacking attachments to species completely covered by agglutinated materials, as in the Mediterranean species Xenophora crispa. Here, we analyse Recent and fossil specimens of Xenophora crispa from the Mediterranean area using SEM and XRD, to better understand their biomineralization patterns and the mechanisms leading to the agglutination of shells, bioclasts and lithoclasts, and their evolution in time. We also provide new data on poorly studied gastropod shell microstructures. We conclude that: (1) most of the Xenophora crispa shell consists of an aragonitic crossed lamellar fabric, but fibrous to spherulitic prismatic fabrics, seemingly of calcite, have been found in the columella and peripheral edge (the thickest parts of the shell); (2) attachment of objects is mediated by a prismatic microstructure, indicating that this may be the most functional fabric in attachment areas in molluscs; and (3) the functional purpose of the agglutination in Xenophora crispa may be related to a snowshoe strategy to successfully colonize muddy substrates, coupled with tactile and olfactory camouflage. Indeed, this species secretes in the columella and peripheral edge a less dense and a more organic rich calcitic fabric, possibly to lighten the shell thickest parts in order not to sink in soft sediments and to facilitate the shell raising from the substrate to create a protected feeding area. This behaviour seems to have been maintained by X. crispa over 2 My time span.  相似文献   

13.
14.
Tapinoma wilsonisp. n. is described and illustrated from Saudi Arabia based on the worker caste collected from Al Baha, Saudi Arabia. It closely resembles Tapinoma lugubre Santschi 1917, from Zimbabwe in body measurements but can be distinguished from the latter species by the yellowish brown color; the yellowish pubescence, the two pairs of hairs present on the anterior part of the head; and the distinctly concave anterior clypeal margin. Biological and ecological notes of the new species are presented. An identification key to the workers of the Arabian species of the genus Tapinoma is given.  相似文献   

15.
Willows (Salix: Salicaceae) form a major ecological component of Holarctic floras and consequently are an obvious target for a DNA‐based identification system. We surveyed two to seven plastid genome regions (~3.8 kb; ~3% of the genome) from 71 Salix species across all five subgenera, to assess their performance as DNA barcode markers. Although Salix has a relatively high level of interspecific hybridization, this may not sufficiently explain the near complete failure of barcoding that we observed: only one species had a unique barcode. We recovered 39 unique haplotypes, from more than 500 specimens, that could be partitioned into six major haplotype groups. A unique variant of group I (haplotype 1*) was shared by 53 species in three of five Salix subgenera. This unusual pattern of haplotype sharing across infrageneric taxa is suggestive of either a massive nonrandom coalescence failure (incomplete lineage sorting), or of repeated plastid capture events, possibly including a historical selective sweep of haplotype 1* across taxonomic sections. The former is unlikely as molecular dating indicates that haplotype 1* originated recently and is nested in the oldest major haplotype group in the genus. Further, we detected significant non‐neutrality in the frequency spectrum of mutations in group I, but not outside group I, and demonstrated a striking absence of geographical (isolation by distance) effects in the haplotype distributions of this group. The most likely explanation for the patterns we observed involves recent repeated plastid capture events, aided by widespread hybridization and long‐range seed dispersal, but primarily propelled by one or more trans‐species selective sweeps.  相似文献   

16.
Five ruthenium(II) complexes, i.e., [Ru(bpy)2(TIP)]2+ (bpy=2,2′‐bipyridine; TIP=2‐thiophenimidazo[4,5‐f] [1,10]phenanthroline; 1 ), [Ru(bpy)2(5‐NTIP)]2+ (5‐NTIP=2‐(5‐nitrothiophen)imidazo[4,5‐f] [1,10]phenanthroline; 2 ), [Ru(bpy)2(5‐MOTIP)]2+ (5‐MOTIP=2‐(5‐methoxythiophen)imidazo[4,5‐f] [1,10]phenanthroline; 3 ), [Ru(bpy)2(5‐BTIP)]2+ (5‐BTIP=2‐(5‐bromothiophen)imidazo[4,5‐f] [1,10]phenanthroline; 4 ), and [Ru(bpy)2(4‐BTIP)]2+ (4‐BTIP=2‐(4‐bromothiophen)imidazo[4,5‐f] [1,10]phenanthroline; 5 ), were synthesized and characterized by elemental analysis and UV/VIS, IR, and 1H‐NMR spectroscopic methods. The photophysical and DNA‐binding properties were investigated by means of UV and fluorescence spectroscopic methods and viscosity measurements, respectively. The results suggest that all five complexes can bind to CT‐DNA with various binding strength. Complexes 2 and 3 showed the strongest and the weakest binding affinity, respectively, among these five complexes. Due to the substituent position of the Br‐atom in the ligand, complex 5 interacted stronger with CT‐DNA than complex 4 . The binding affinities of the complexes decreased in the order 2, 5, 4, 1 , and 3 .  相似文献   

17.
18.
Igor M. Sokolov 《ZooKeys》2013,(352):51-92
One new genus and eight new species of anilline carabids are described from southern Mexico. The new genus, Zapotecanillus gen. n., is established for Z. oaxacanus (type species) sp. n., Z. nanus sp. n., Z. iviei sp. n., Z. ixtlanus sp. n., Z. montanus sp. n., and Z. kavanaughi sp. n. from the Sierra Madre de Oaxaca, Z. pecki sp. n. from the Sierra Madre del Sur, and Z. longinoi sp. n. from the Sierra Madre de Chiapas. A taxonomic key for all described species of Zapotecanillus and a cladistic analysis, based on morphological data, are provided. Morphological, behavioral and biogeographical aspects of the speciation in the genus obtained from the resulting cladogram are discussed.  相似文献   

19.
Although the genus Leucothoe has been reported repeatedly in the Magellan Region, the citations in the Channels and Fjords Ecoregion were either unidentified or attributed to the previously considered cosmopolitan Leucothoe spinicarpa. In this work, Leucothoe kawesqari sp. n. is described, which can be distinguished from other species of the genus in the Southern Ocean by having eyes present, epimeral plates with no setae, anterior coxae not acutely produced or excavate, coxa 5 slightly bilobed, accessory flagellum present, mandibular palp article 3 shorter than ½ article 2, pereopods 5–7 basis expanded, ovoid, posterior margin weakly crenulate and telson apex irregularly truncated. The new species was found in hard substrates, both unvegetated and with macroalgae, mainly in kelp forest of Macrocystis pyrifera.  相似文献   

20.
Collecting reef-fish specimens using a manned submersible diving to 300 m off Curaçao, southern Caribbean, is resulting in the discovery of numerous new fish species. The new Liopropoma sea bass described here differs from other western Atlantic members of the genus in having VIII, 13 dorsal-fin rays; a moderately indented dorsal-fin margin; a yellow-orange stripe along the entire upper lip; a series of approximately 13 white, chevron-shaped markings on the ventral portion of the trunk; and a reddish-black blotch on the tip of the lower caudal-fin lobe. The new species, with predominantly yellow body and fins, closely resembles the other two “golden basses” found together with it at Curaçao: L. aberrans and L. olneyi. It also shares morphological features with the other western Atlantic liopropomin genus, Bathyanthias. Preliminary phylogenetic data suggest that western Atlantic liopropomins, including Bathyanthias, are monophyletic with respect to Indo-Pacific Liopropoma, and that Bathyanthias is nested within Liopropoma, indicating a need for further study of the generic limits of Liopropoma. The phylogenetic data also suggest that western Atlantic liopropomins comprise three monophyletic clades that have overlapping depth distributions but different depth maxima (3–135 m, 30–150 m, 133–411 m). The new species has the deepest depth range (182–241 m) of any known western Atlantic Liopropoma species. Both allopatric and depth-mediated ecological speciation may have contributed to the evolution of western Atlantic Liopropomini.  相似文献   

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