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1.
The anatomy and innervation of the lateral external muscle and sensory cells located in the ventral region of pregenital abdominal segments were examined at the larval and adult stages ofTenebrio molitor (Coleoptera). All seven muscles located in this region degenerate during the pupal stage, whilst only the lateral external median (lem) appears in the adult. Backfillings of the motor nerve innervating this muscle reveal that, at both larval and adult stages, it is innervated by ten neurons. Intracellular records from the muscle fibres show that two neurons are inhibitory, and at least five are excitatory. There are also two unpaired neurons. A variety of sensory organs are located in the ventral region of the larvae, whilst only campaniform sensilla are found in the adult. At both stages, the innervation pattern of the sensory nerve branches is very similar. Also, the central projections of the sensory cells occupy similar neuropilar areas. Finally, prolonged intracellular records from the lem muscle revealed that, at the larval stage, it participates only in segmental or intersegmental reflexes, whilst in the adult it has a primary expiratory role in ventilation. The results show that extensive changes occur in the number of muscles located in the ventral region of the pregenital abdominal segments, as well as in the arrangement and number of sensory neurons, in the structure of the exoskeleton, and even in the central nervous system. In contrast, only minor changes are observed in the sensory and motor nerve branches, in the sensory projections, and in the number and the location of the motoneurons innervating the lateral external median muscle. Correspondence to: G. Theophilidis  相似文献   

2.
External and internal head structures of Caurinus dectes were examined and described in detail. The features are compared to conditions found in other groups of Antliophora. Caurinus is obviously crucial for the reconstruction of the mecopteran and antliophoran groundplan. It displays a remarkable series of plesiomorphic character states such as a complete clypeolabral suture, the presence of M. hypopharyngomandibularis (M. 13) and M. frontohypopharyngalis (M. 41), a subdivided clypeus, a short head without rostrum, a dorsal tentorial arm attached to the head capsule, the absence of a cranial dilator of the antenna, and large mandibles with a well developed apical tooth, two distinct subapical teeth, and a basal molar part. The first three plesiomorphic features render potential autapomorphies of Mecoptera in the traditional sense invalid. Autapomorphies of Caurinus are the distinctly flattened labrum, the absence of the labroepipharyngeal muscle, the very large size of M. 13, the strongly enlarged penultimate palpomeres, the partition of M. 41, the very strongly developed precerebral sucking chamber, strongly curved optic lobes, the presence of a large protocerebral extension in the genal region and deep posterior excavations of the protocerebrum. The maxillolabial plate, the absence of cardines as separate structures, the reduction of ocelli, and the origin of maxillary palp muscles on a median ridge or area of the maxillolabial plate are likely autapomorphies of Boreidae. Another potential autapomorphy of the family is the presence of longitudinal furrows on the mandibles. However, they are absent in Boreus. The thick strongly sclerotised, median ridge of the maxillolabial plate, the missing retractibility of the prementum, the absence of extrinsic labial muscles, and the presence of a median ridge on the prepharyngeal roof suggest a clade Boreus + Hesperoboreus. The origin of extrinsic maxillary muscles from the clypeus has probably evolved independently in Boreus and Hesperoboreus, and in Panorpa, respectively. The absence of M. craniolacinialis and the presence of a row of several subapical mandibular teeth are autapomorphies of Boreus. The presence of a specific intrinsic muscle of the salivary duct and a membranous galea enclosing the labrum and mandibular base are derived features shared by Boreidae and Pistillifera (galea absent in Nannochorista, Siphonaptera and Diptera). The loss of M. frontolabralis (M. 8) is a potential apomorphy of Mecoptera incl. Siphonaptera. A sister group relationship between Boreidae and Siphonaptera is not supported by characters of the adult head. Head structures of Siphonaptera are extremely modified in correlation with ectoparasitic habits.  相似文献   

3.
The antennae of Lepidoptera Neopseustidae were examined with the scanning electron microscope. The studied species, Nematocentropus cfr. omeiensis, Neopseustis meyricki, Synempora andesae, Apoplania valdiviana and Apoplania penai possess nine types of antennal flagellum sensilla: multiporous large sensilla basiconica, multiporous thin sensilla basiconica, multiporous small sensilla basiconica, multiporous sensilla trichodea, multiporous sensilla coeloconica; uniporous sensilla chaetica; aporous sensilla chaetica, aporous stylus-shaped sensilla chaetica, aporous sensilla styloconica.The multiporous sensillum type here termed “multiporous large sensillum basiconicum” is unknown from other Lepidoptera and probably constitutes an autapomorphy of the family Neopseustidae. This sensillum type is remarkable by having a single base in female Apoplania and Synempora while in male Apoplania it has a bifid or trifid base, and in male Synempora it is composed of two or three incompletely separated hairs. This may be the first recorded example of a sexually dimorphic lepidopteran sensillum type. The stylus-shaped sensillum chaeticum is a primitive type which occurs only in some lower Lepidoptera.  相似文献   

4.
A new genus and species of stick insect is described and figured from Mount Halcon, on the Philippine island of Mindoro. Conlephasma enigma gen. et sp. n. is a stout, flightless, and apparently ground-dwelling species with vivid integumental colors. When disturbed, specimens spray a defensive secretion from the prothoracic exocrine glands. The systematic position of Conlephasma within Euphasmatodea is unclear. The elongated galealobulus and the trichome area located laterally in the galea, represent unusual apomorphic characters of the maxilla that could indicate affinities with Necrosciinae or Pseudophasmatinae. All tibiae exhibit the anareolate condition. Euplantulae are of two types: those of tarsomeres I–IV feature a nubby microstructure, whilst the one on the ventral side of the pretarsus is smooth. Males are characterized by the presence of a well-developed vomer on the tenth abdominal segment. A distinctive and apomorphic trait of female terminalia is represented by the elongated tenth abdominal tergum. Conlephasma can represent an interesting taxon for studies on the evolution of the stick and leaf insects.  相似文献   

5.
6.
The presumed sixth limb of Dumontia Santos-Flores & Dodson, 2003 is shown to correspond to the inner part of the fifth limb. Comparison of the latter structure within the order increases the similarity between the Dumontiidae and the Daphniidae (plus Moinidae), but important similarities with the Radopoda remain. The relationship between a ‘‘daphniid line’’ and radopods needs further attention. Handling editor: K. Martens  相似文献   

7.
Friedemann K., Wipfler B., Bradler S. and Beutel R.G. 2011 . On the head morphology of Phyllium and the phylogenetic relationships of Phasmatodea (Insecta). —Acta Zoologica (Stockholm) 00 : 1–16. External and internal head structures of Phyllium siccifolium are described in detail. The findings are compared with conditions found in other phasmatodeans and members of other neopteran lineages. The compiled 125 characters were analysed cladistically. A clade Eukinolabia (Phasmatodea + Embioptera) was confirmed. Synapomorphies of these two taxa are the shift of the origin of M. tentorioparaglossalis to the hind margin of the prementum, the presence of M. tentorioscapalis medialis, and antennal muscles that originate exclusively on the anterior tentorial arms. Within Eukinolabia, the position of Timema remains somewhat ambiguous because of missing anatomical data. However, it was confirmed as sister group of Euphasmatodea in a monophyletic Phasmatodea. Apomorphic groundplan features of Euphasmatodea are salivary ducts with separate external openings, apically rounded glossae, the presence of the galealobulus, and the reduction of the antennifer. The monophyly of Neophasmatidae was confirmed. Autapomorphies are the loss of M. frontobuccalis posterior, the anteriorly or dorsally directed maxillary palps, and the reduction of the mandibular incisivi. The analysis of characters of the head yielded three new autapomorphies of Phylliinae, the presence of a protuberance on the attachment site of the dorsal tentorial arms, dorsoventrally flattened maxillary‐ and labial palps, and possibly the narrow and U‐shaped field of trichomes on the apical part of the galea.  相似文献   

8.
A phylogeny based on the internal transcribed spacer (ITS) sequences from 79 taxa representing much of the diversity of Berberis L. (four major groups and 22 sections) was constructed for the first time. The phylogeny was basically congruent with the previous classification schemes at higher taxonomic levels, such as groups and subgroups. A notable exception is the non-monophyly of the group Occidentales of compound-leaved Berberis (previously separated as Mahonia). At lower levels, however, most of previous sections and subsections were not evident especially in simple-leaved Berberis. Possible relationship between section Horridae (group Occidentales) and the simple-leaved Berberis clade implies paraphyly of the compound-leaved Berberis. A well-known South America-Old World (mainly Asia) disjunctive distribution pattern of the simple-leaved Berberis is explained by a vicariance event occurring in the Cretaceous period. The ITS phylogeny also suggests that a possible connection between the Asian and South American groups through the North American species (Berberis canadensis or B. fendleri) is highly unlikely.  相似文献   

9.
This paper investigates the usefulness of two mitochondrial genes (16S rRNA and cytochrome b) to solve taxonomical difficulties within the genus Hylomyscus and to infer its evolutionary history. Both genes proved to be suitable molecular markers for diagnosis of Hylomyscus species. Nevertheless the resolving powers of these two genes differ, and with both markers (either analyzed singly or in combination), some nodes remain unresolved. This is probably related to the fact that the species emerged during a rapid diversification event that occurred 2-6 Myr ago (4-5 Myr ago for most divergence events). Our molecular data support the recognition of an "aeta" group, while the "alleni" and "parvus" groups are not fully supported. Based on tree topology and genetic divergence, two taxa generally recognized as subspecies should be elevated at the species level (H. simus and H. cf kaimosae). H. stella populations exhibit ancient haplotype segregation that may represent currently unrecognized allopatric species. The existence of cryptic species within H. parvus is questioned. Finally, three potentially new species may occur in West Central Africa. The Congo and Oubangui Rivers, as well as the Volta and Niger Rivers and/or the Dahomey gap could have formed effective barriers to Hylomyscus species dispersal, favoring their speciation in allopatry. The pronounced shifts in African climate during the late Pliocene and Miocene, which resulted in major changes in the distribution and composition of the vegetation, could have promoted speciation within the genus (refuge theory). Future reports should focus on the geographic distribution of Hylomyscus species in order to get a better understanding of the evolutionary history of the genus.  相似文献   

10.
We investigated the phylogenetic relationships among most Chinese species of lizards in the genus Phrynocephalus (118 individuals collected from 56 populations of 14 well-defined species and several unidentified specimens) using four mitochondrial gene fragments (12S rRNA, 16S rRNA, cytochrome b, and ND4-tRNA(LEU)). The partition-homogeneity tests indicated that the combined dataset was homogeneous, and maximum-parsimony (MP), neighbor-joining (NJ), maximum-likelihood (ML) and Bayesian (BI) analyses were performed on this combined dataset (49 haplotypes including outgroups for 2058bp in total). The maximum-parsimony analysis resulted in 24 equally parsimonious trees, and their strict consensus tree shows that there are two major clades representing the Chinese Phrynocephalus species: the viviparous group (Clade A) and the oviparous group (Clade B). The trees derived from Bayesian, ML, and NJ analyses were topologically identical to the MP analysis except for the position of P. mystaceus. All analyses left the nodes for the oviparous group, the most basal clade within the oviparous group, and P. mystaceus unresolved. The phylogenies further suggest that the monophyly of the viviparous species may have resulted from vicariance, while recent dispersal may have been important in generating the pattern of variation among the oviparous species.  相似文献   

11.
A molecular analysis was performed on 56 taxa in the orchid genus Cypripedium using nrDNA ITS and five chloroplast regions (trnH-psbA, atpI-atpH, trnS-trnfM, trnL-F spacer, and the trnL intron). The genus Cypripedium was confirmed as monophyletic. Our data provided strong support for monophyletic grouping of eight infrageneric sections (Subtropica, Obtusipetala, Trigonopedia, Sinopedilum, Bifolia, Flabelinervia, Arietinum, and Cypripedium) defined in earlier taxonomic treatments, and paraphyletic grouping of two sections (Irapeana and Retinervi). Within the genus Cypripedium, the first divergent lineage consisted of two Mesomaerican species, and subsequently the Cypripedium debile lineage from eastern Asia was split. Our study did not support the notion that two Asian species (Cypripedium subtropicum and Cypripedium singchii) were closely related to either Mesoamerican Cypripedium irapeanum or North American Cypripedium californicum, as indicated by previous interpretations based on morphological evidences. In addition, one pair of vicariant species, Cypripedium plectrochilum (eastern Asia) and Cypripedium arietinum (North America), unique to section Arietinum, was confirmed. Furthermore, within the monophyletic section Cypripedium two previously recognized subsections, Cypripedium and Macrantha, were shown to be paraphyletic. Our results suggested that this section split into two groups based on distribution (North America vs. Eurasia) instead of such previously used, morphological traits as flower color, and the shape of the lips (labellum) and lateral petals.  相似文献   

12.
The African gerbils of the genus Tatera are widespread and abundant throughout sub-Saharan Africa. There is still today a certain controversy concerning the taxonomy of these rodents and very few attempts have been made to assess their systematic relationships. The present paper introduces findings based on the partial sequences of cytochrome b (495 bp) and the 16S rRNA (469 bp) mitochondrial genes of six (T. robusta, T. nigricauda, T. vicina, T. leucogaster, T. valida, and T. kempi) species together with two additional taxa. We also report the karyotypes of T. vicina and T. leucogaster. We propose that T. vicina should be considered as a valid species and show the monophyly of the robusta species group, with the exclusion of T. leucogaster. Our results show there is a different chromosomal evolutionary pattern within the two major lineages, which is recognizable through molecular phylogenetics. One is characterized by karyotype stability and the other by a considerable number of chromosomal rearrangements. The lineage divergence coincides with the formation of the East African Rift. The processes that led to the origin of the East African species seem to be related to the subsequent climatic changes, which caused cyclic contraction and expansion of the savannah biomes. Furthermore, geological activities that characterized East Africa during Plio-Pleistocene may also have contributed to lineage divergence.  相似文献   

13.
Phylogenetic analyses of the genusActaea were performed using morphological, ecological and biogeographical characters. Using solely morphological characters, the relationships of the three identified species-groups remain uncertain. Close biogeographical examination and comparison of the areas with ecological peculiarities as well as climate data gave important insight into the phylogeny ofActaea and the whole tribe. Consequently, the obtained biogeographical data were used for phylogenetic reconstructions. Both, from the point of view of morphological and biogeographical data,A. pachypoda andA. asiatica are the most ancestral species. They grow on the east sides of the continents, mainly in broad-leaved forests. In West Eurasia the apomorphicA. spicata andA. acuminata occur under similar climatic and ecological conditions, but these species are adapted to another climate rhythm. The most advanced species (A. erythrocarpa, A. rubra) are to be found in the boreal forests where they are widely distributed. This biogeographical approach revealed that the evolution of the species led to a gradual widening and shifting of their ecological constitutions.  相似文献   

14.
As an introduced plant, Lablab purpureus serves as a vegetable, herbal medicine, forage and green manure in China. In order to investigate the diversity of rhizobia associated with this plant, a total of 49 rhizobial strains isolated from ten provinces of Southern China were analyzed in the present study with restriction fragment length polymorphism and/or sequence analyses of housekeeping genes (16S rRNA, IGS, atpD, glnII and recA) and symbiotic genes (nifH and nodC). The results defined the L. purpureus rhizobia as 24 IGS-types within 15 rrs-IGS clusters or genomic species belonging to Bradyrhizobium, Rhizobium, Ensifer (synonym of Sinorhizobium) and Mesorhizobium. Bradyrhizobium spp. (81.6%) were the most abundant isolates, half of which were B. elkanii. Most of these rhizobia induced nodules on L. purpureus, but symbiotic genes were only amplified from the Bradyrhizobium and Rhizobium leguminosarum strains. The nodC and nifH phylogenetic trees defined five lineages corresponding to B. yuanmingense, B. japonicum, B. elkanii, B. jicamae and R. leguminosarum. The coherence of housekeeping and symbiotic gene phylogenies demonstrated that the symbiotic genes of the Lablab rhizobia were maintained mainly through vertical transfer. However, a putative lateral transfer of symbiotic genes was found in the B. liaoningense strain. The results in the present study clearly revealed that L. purpureus was a promiscuous host that formed nodules with diverse rhizobia, mainly Bradyrhizobium species, harboring different symbiotic genes.  相似文献   

15.
16.
The subalpine warbler Sylvia cantillans is formally considered a polytypic species, with four subspecies, European S. c. cantillans, albistriata, moltonii (recently resumed name: subalpina) and North African S. c. inornata. They are very similar in external morphology but clearly differ in their vocalizations. We evaluated their uncertain taxonomic status reconstructing the phylogenetic and phylogeographic relationships among populations sampled across major biogeographical areas in the European species’ range, using nucleotide sequences of the mitochondrial cytochrome b gene (mtDNA cyt b). A variety of phylogenetic analyses concordantly led to identify four major groups, only partially corresponding to the three European nominal subspecies. Phylogenetic trees showed a monophyletic group including all moltonii individuals, well diverged from all other taxa. Populations taxonomically assigned to cantillans were polyphyletic being split into two distinct clades (western and southern cantillans), with monophyletic albistriata closely related to southern cantillans. Individuals of moltonii and southern cantillans sampled in sites of sympatry in central Italy were assigned to their respective groups, with perfect concordance between phenotypic and genetic identifications. All findings indicate that moltonii should be ranked as a distinct species. Former subspecies cantillans is polyphyletic, but additional data are needed to define the taxonomic status of its two clades. Albistriata is phylogenetically related to southern cantillans and should be provisionally kept as a subspecies of S. cantillans. The cantillans complex thus provides an interesting case-study illustrating geographical structuring across small geographical ranges, and it exemplifies speciation through differentiation in allopatry leading to reproductive isolation after a secondary contact.  相似文献   

17.
Parsimony analyses of the internal transcribed spacer regions of nuclear ribosomal DNA (ITS 1 & ITS 2) for 38 taxa sampled from the Phebalium group (Rutaceae: Boronieae) and two outgroups confirm that, with the exception of Phebalium sensu stricto and Rhadinothamnus, six of the currently recognised genera within the group are monophyletic. The data indicate that Phebaliums. str. is paraphyletic with respect to Microcybe, and Rhadinothamnus is paraphyletic with respect to Chorilaena. Rhadinothamnus and Chorilaena together are the sister group to Nematolepis. Drummondita, included as an outgroup taxon, clustered within the ingroup as sister to Muiriantha and related to Asterolasia.The phylogeny suggests that the evolution of major clades within a number of these genera (e.g. Phebalium) relates to vicariance events between eastern and south-western Australia. Leionema is an eastern genus, with the most basal taxon being the morphologically distinct Leionema ellipticum from northern Queensland. Leionema also includes one species from New Zealand, but this species (as with some others) proved difficult to sequence and its phylogenetic position remains unknown. Taxonomic changes at the generic level are recommended.The authors wish to thank Paul G.Wilson, PERTH, for advice and discussion, and Paul Forster, BRI, for collecting and providing material of Leionema ellipticum. The project was supported by a Melbourne University Postgraduate Award (to BM), the Australian Biological Resources Study (ABRS), Australian Systematic Botany Society and Wolf Den (Australia) Investments.  相似文献   

18.
The nonmarine ostracod genus Cypridea s.l., characterized by an antero-ventral “beak” (rostrum and alveolus) in both valves, achieved high diversity and global distribution in the Early Cretaceous but declined in the Late Cretaceous and became extinct during the Paleogene. Although it clearly belongs to the Superfamily Cypridoidea (Order Podocopida, Suborder Cypridocopina), the precise affinities of Cypridea s.l. have been controversial, different authors variously suggesting it to be most closely related to the cypridoidean families Ilyocyprididae, Cyprididae or Notodromadidae. Since Cypridea s.l. was responsible for much of the explosive radiation of nonmarine cypridoidean taxa during the Mesozoic, a clear understanding of its affinities is crucial to the elucidation of nonmarine ostracod phylogeny. We evaluate some of the key morphological features of cypridoidean carapaces as indicators of phylogenetic affinity, paying special attention to adductor muscle scar patterns and the structure of the anterior marginal zone. The morphology of Cypridea s.l. is compared with certain cypridoideans that bear similar beak-like or lip-like antero-ventral marginal structures, notably genera of the Family Cyprididae such as Bennelongia, Chlamydotheca, Cypris and Talicypridea, and consider whether these similarities represent close phylogenetic relationships or homeomorphy.  相似文献   

19.
Euphrasia includes perennial or annual green parasitic plants, and has a disjunct bipolar distribution except for one transtropical connection across the high mountains of Oceania. The disjunction is coupled with strikingly contrasting patterns of morphological diversity between the southern and northern hemispheres, making it an exciting model to study processes of evolutionary diversification which shaped present floras. We inferred the relationships among 51 species representing 14 of the 15 sections of the genus based on nrDNA ITS and cpDNA trnL intron, trnL-trnF and atpB-rbcL intergenic spacers. Maximum parsimony and Bayesian inference support monophyly of the genus and of several intrageneric groups characterized by morphology, ploidy level, and geographic range. Molecular phylogenetic dating using Bayesian “relaxed” clock methods suggests that the earliest Euphrasia radiations occurred minimum 11–8 Mya with bipolarity being achieved 7–5 Mya. Biogeographic analyses using explicit model-based approach inferred Eurasia as an ancestral area for the genus. The most parsimonious reconstruction found by a dispersal-vicariance analysis requires 17 dispersals to account for the current biogeographic pattern and supports Eurasian origin for Euphrasia. Both long-distance dispersal and across land vicariance can be invoked to explain the diversification in the genus, which experienced rapid radiations driven by new ecological opportunities of the late Pliocene and Pleistocene but also retained a set of local endemic or relict species of an earlier origin.  相似文献   

20.
A molecular phylogenetic analysis of the Hyla pulchella species group was performed to test its monophyly, explore the interrelationships of its species, and evaluate the validity of the taxa that were considered subspecies of H. pulchella. Approximately 2.8 kb from the mitochondrial genes 12s, tRNA valine, 16s, and Cytochrome b were sequenced. The analysis included 50 terminals representing 10 of the 14-15 species currently recognized in the H. pulchella group, including samples from several localities for some taxa, several outgroups, as well as two species previously suspected to be related with the group (Hyla guentheri and Hyla bischoffi). The results show that the H. pulchella and Hyla circumdata groups are distantly related, and, therefore, should be recognized as separate groups. As currently defined, the H. pulchella group is paraphyletic with respect to the Hyla polytaenia group; therefore, we recognize the Hyla polytaenia clade in the H. pulchella group. Two subspecies of H. pulchella recognized by some authors are considered full species including Hyla pulchella riojana because it is only distantly related to H. pulchella, and Hyla pulchella cordobae because molecular and non-molecular evidence suggests that it is specifically distinct. With the inclusion of the H. polytaenia clade, H. guentheri, and H. bischoffi, and the recognition of the two former subspecies of H. pulchella as distinct species, the H. pulchella group now comprises 25 described species. All representatives of the H. pulchella group with an Andean distribution are monophyletic and nested within a clade from the Atlantic forest from south-southeastern Brazil/northeastern Argentina, and Cerrado gallery forest from central Brazil.  相似文献   

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