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1.
The angelfish,Centropyge multispinis, hitherto assigned to the subgenusXiphypops Jordan, 1922 is transferred to the subgenusCentropyge Kaup, 1860, on the basis of anatomical characters. Comparison of adult specimens ofC. (C.) multispinis with 5 other species,C. (C.) nox, C. (C.) eibli, C. (X.) shepardi, C. (X.) flavicauda, andC. (X.) acanthops, confirmed its subgeneric status.  相似文献   

2.
The pollen morphology of all 23 Japanese species ofSymplocos (1 of subgenusEusymplocos, and 22 of subgenusHopea) was comprehensively studied using LM, SEM and TEM, and found to be classifiable into two types (Type I and II) primarily on the basis of wall structure. Type I, characterized by a thick tectum lacking a supratectal structure and reduced columellae, occurs in subgenusEusymplocos, while Type II, characterized by a thin tectum with a supratectal structure and generally distinct columellae, occurs in subgenusHopea. Resemblances in wall structure suggest a closer relationship of subgenusEusymplocos to subgenusMicrosymplocos as well as of subgenusHopea to subgenusEpigenia. This fact contradicts the earlier proposed infrageneric classification, and may require its revision. Within Type II, five subtypes are recognized primarily on the basis of sculpture combined with other pollen characters. Systematic value of sculpture (i.e., subtype), aperture morphology and “globules”, as well as certain species relationships based on those characters, are also discussed.  相似文献   

3.
Phylogenetic analysis of the plastid (chloroplast) DNA matK gene of Zosteraceae species was undertaken. A molecular phylogenetic tree based on matK sequence data showed the monophyly of Heterozostera tasmanica and subgenus Zosterella and did not support the separation of Heterozostera from the genus Zostera. The tree based on matK supported the monophyly of the subgenus Zostera, and showed that Zosteraceae consist of three main groups: Phyllospadix, which is clearly defined by being dioecious; the subgenus Zosterella and Heterozostera; and the subgenus Zostera. Character-state reconstruction of chromosome number and geographic distribution for our molecular phylogenetic tree showed that 2n=12 is a plesiomorphic character for Zostera and Heterozostera, that the chromosome number was doubled or tripled in two lineages, and that the initial speciation of Zostera and Heterozostera occurred in the Northern Hemisphere. The matK tree showed the close affinity of Z. noltii and Z. japonica, which have disjunct distributions. Zostera marina, which is the only widely distributed species in the subgenus Zostera, also occurring in the northern Atlantic, was shown to be embedded within other subgenus Zostera species.  相似文献   

4.
Although the presence of socially controlled sex change in pomacanthid fishes of the genusCentropyge has been known since 1978, it has always been assumed that such sex change occurred only after the death or disappearance of the dominant male in single male social groups. Between 1978 and 1983, we observed several incidences of sex change by ranking female angelfishes within their harems and in the presence of the dominant male in each such harem. This phenomenon was observed inCetropyge interruptus andCentropyge tibicen, and occurred frequently enough to suggest the possibility of early sex change as a normal reproductive strategy in these species. Possible advantages of early sex change are discussed.  相似文献   

5.
Thirty species and one variety of Symplocos (Symplocaceae), including all taxa distributed in Japan, were phylogenetically analyzed with DNA sequence data. The evolution of morphological characters is discussed on the basis of the phylogenetic relationships obtained. All species were Asian, except one, S. austromexicana, from Mexico. The nuclear ribosomal internal transcribed spacer (ITS) region and two intergenic spacer regions, between trnL and trnF, and between trnH and psbA of chloroplast DNA were used. The topologies of trees obtained from ITS and the chloroplast intergenic spacers are largely congruent. S. sonoharae, the representative of the subgenus Symplocos in Asia, was sister to all other species. The position of the American species, S. austromexicana, which also belongs to the subgenus Symplocos, was not well resolved. The phylogenetic tree based on combined sequence data largely supports the monophyletic origin of the infrageneric sections proposed earlier. However, the phylogenetic relationship between them is not well resolved, probably due to rapid diversification. The section Palura, a deciduous group, is well defined in the DNA analysis, suggesting its independent status in the genus Symplocos. In spite of their morphological divergence, the three endemic species of the Bonin Islands are monophyletic. The occurrence of curved seeds seems to be homoplastic, scattered over the phylogenetic tree without showing a particular infrageneric relationship.  相似文献   

6.
The family Lebachacanthidae was erected for“Orthacanthus” senkenbergianus, a xenacanthiform from the Lower Permian of Lebach (Germany). Recently, the validity of the family has been questioned and the type species,Lebachacanthus senkenbergianus, has been included in the genusOrthacanthus Agassiz 1843, subgenusLebachacanthus Soler-Gijón 1997. Arguments against such changes are presented here. Anew phylogenetic analysis is performed in order to determine the relationships of Lebachacanthidae with the rest of xenacanthiforms.Hagenoselache, a xenacanthiform recently described from the Namurian of Germany, is included in the phylogenetic analysis together with new data on tooth histology. The new phylogenetic analysis confirms Lebachacanthidae as a distinct family within Xenacanthiformes. Lebachacanthidae is the sister group of Xenacanthidae which includes trueOrthacanthus. Hagenoselache is more derived thanDiplodoselache (the most primitive xenacanthiform) and is the sister group of the clade formed by Lebachacanthidae and Xenacanthidae. The phylogenetic position of Lebachacanthidae is consistent with the idea of heterochronic processes in the evolution of the xenacanth sharks. Heterochrony (peramorphic type) can explain morphological clines in dorsal spine morphology from basal xenacanthiforms (Diplodoselachidae) through Lebachacanthidae to the derived Xenacanthidae (comprisingOrthacanthus, Xenacanthus, Triodus andPlicatodus).  相似文献   

7.
We modelled the effect of habitat heterogeneity on the abundance of the submediterranean Saponaria bellidifolia, a red list species in Romania. The study was designed at two scales: 100 and 0.5 m2. At larger scale, generalized additive models and canonical correspondence analysis were used to model the density of ramets, whereas at microscale, binomial logistic regression was employed to model the species’ occurrence. S. bellidifolia abundance responded sensitively to habitat type (classified as “grassy”, “rocky” and “scree”), rather than to microclimatic variables. At both scales, habitat type was the best predictor of ramet abundance, followed by slope and vegetation cover. At 0.5 m2, soil depth was also a good predictor of species occurrence. The data revealed that screes are the most suitable habitats for hosting relatively large populations of this rare species, because of occasional natural disturbances and presumably lower interspecific competition.  相似文献   

8.
The molecular phylogeny of 36 specimens of JapaneseAmanita species was studied based on nucleotide sequences of the internal transcribed spacer (ITS) region of nuclear ribosomal DNA. The phylogenetic tree obtained supported the traditional classification systems of Bas (1969) and Singer (1986), which are based on morphological characters, in the division of the genusAmanita is divided into subgeneraAmanita andLepidella by the amyloidity of basidiospores. However, at section-level, we suggest that subgenusAmanita should be divided into three sections (Amanita, Vaginatae, andCaesareae). Our results also showed the necessity to modify the taxonomic treatments at section-level in the subgenusLepidella. It appears that the establishment ofA. muscaria andA. pantherina from a common ancestral species might be a very recent event, or these might be lower taxa of same species. As for three subspecies ofA. hemibapha and three varieties ofA. vaginata, it is necessary to grade up their taxonomical ranks from subspecies/variety to species. A new combination,A. javanica, is proposed forA. hemibapha subsp.javanica.  相似文献   

9.
Aechmea itapoana is a new, conspicuous and distinct species from the coastal sand dune scrub of N.E. Brazil. Its possible relationships within subgenusChevaliera, toA. multiflora andA. rodriguesia are discussed.  相似文献   

10.
We present a phylogenetic and morphological study of the grassland earless dragon, Tympanocryptis pinguicolla, an endangered habitat specialist that occurs in a few isolated populations in eastern Australia. Tympanocryptis pinguicolla occurred historically in Victoria in south-eastern Australia, but has not been seen since 1990, and current populations are known in New South Wales and Canberra in south-eastern Australia. Recently, new populations identified as T. pinguicolla were discovered on the Darling Downs, Queensland. Translocation of individuals between these populations has been suggested as a conservation management strategy to maintain genetic diversity. To address this issue, we undertook a phylogenetic study of all major populations of T. pinguicolla using a 1838 bp region of mitochondrial DNA, incorporating ND1, ND2, COI and eight tRNA genes. We incorporated specialized degraded-DNA techniques to amplify DNA from historical museum specimens, as no extant tissue was available for Victorian populations. Our results, which include morphological analysis, provide convincing evidence that populations currently identified as T.␣pinguicolla do not comprise a monophyletic species, as the populations from the Darling Downs are more closely related to T. tetraporophora than to T. pinguicolla. In addition, we find that there is a significant level of haplotype divergence between populations of T. pinguicolla, indicating that these lineages separated at least 1.5 mya. Our results suggest translocation may not be an appropriate management strategy and our findings that Darling Downs populations are not T.␣pinguicolla will significantly influence the conservation management of this species in Queensland.  相似文献   

11.
Noel H. Holmgren 《Brittonia》1976,28(2):195-208
Castilleja subgenusCastilleja in the northern half of Mexico consists of nine species, which are treated here. The subgenus is characterized by a conspicuously colored calyx that is much more deeply cleft in front (abaxially) than in back (adaxially).Castilleja rhizomata,C. linifolia,C. mcvaughii, andC. pterocaulon are described as new, and are illustrated and mapped. The first three are compared toC. patriotica and C.tenuiflora, their closest relatives in the Tenuiflorae group, and the fourth is compared toC. ortegae, with which it constitutes the Ortegae group.Castilleja roei andC. tenuifolia of the Epichroma group are included in order to complete the census of subgenusCastilleja as encountered in the region of the new species. A key to the nine species of subgenusCastilleja from the northern half of Mexico is provided.  相似文献   

12.
Three DNA probes isolated from three species ofReithrodontomys (R. montanus, R. megalotis, R. fulvescens) were used to examine within and among species variation in the chromosomal location of satellite DNA and constitutive heterochromatin. These probes hybridized to the centromeric regions on all chromosomes in six species of the subgenusReithrodontomys. Additionally, nearly all extra-centromeric C-band positive regions (with the exception of some heterochromatic material on the X and Y) hybridized to these probes. Within the subgenusReithrodontomys both the chromosomal distribution and organization of satellite DNA has changed throughout evolution. The evolutionary transition has been from a totally centromeric position inR. fulvescens to centromeric and non-centromeric regions in other species that have undergone extensive chromosomal rearrangements from the primitive karyotype for peromyscine rodents. In addition, the monomer repeat of the satellite sequence differs betweenR. fulvescens (monomer defined by PstI) and the remaining species in the subgenusReithrodontomys (monomer defined by EcoRI). These results suggest at least two amplification events for this satellite DNA sequence. Models and mechanisms concerned with the homogenization and spread of satellite sequences in complex genomes are evaluated in light of theReithrodontomys data. From a phlyogenetic standpoint, the satellite sequences composing heterochromatic regions were restricted to the subgenusReithrodontomys, which supports morphological differences used to recognize two subgenera,Reithrodontomys andAporodon. Probes failed to hybridize to any part of the karyotype ofR. mexicanus (subgenusAporodon) or to seven species from other closely related genera (Baiomys, Neotoma, Nyctomys, Ochrotomys, Onychomys, Peromyscus, Xenomys), some of which are considered as potential sister taxa forReithrodontomys.  相似文献   

13.
Seedling morphology was studied in 22 species ofLespedeza, of which six belong to subgenusMacroles-pedeza and 16 to subgenusLespedeza. Two seedling types were recognized: 1) those with opposite leaves at the first node; 2) those having the first and subsequent leaves alternate. The two types are distinguished in the number of leaf primordia in the plumule of the seed: the opposite type has two leaf primordia, but the alternate type has only one primordium. Most species exhibited one of the two types, but rarely both types were observed in several species. In species having two types, one type always far outnumbers the other. The opposite type was common in Asian species, while the alternate type was common in North American ones. Because seedlings are of the opposite type inKummerowia which is the most closely related genus withLespdeza, the alternate type is considered to be apomorphic inLespedeza. The apomorphic seedling morphology is, there-fore, dominantly occurred in North American species ofLespedeza. This fact may be an evidence which suggests a monophyletic origin for North American species from an Asian ancesfor.  相似文献   

14.
Body shape is predicted to differ among species for functional reasons and in relation to environmental niche and phylogenetic history. We quantified morphological differences in shape and size among 98.5% of the 129 species and all 21 genera of the Australo‐Papuan endemic myobatrachid frogs to test the hypothesis that habitat type predicts body shape in this radiation. We tested this hypothesis in a phylogenetic context at two taxonomic levels: across the entire radiation and within the four largest genera. Thirty‐four external measurements were taken on 623 museum specimens representing 127 species. Data for seven key environmental variables relevant to anurans were assembled for all Australian‐distributed species based on species' distributions and 131,306 locality records. The Australo‐Papuan myobatrachid radiation showed high diversity in adult body size, ranging from minute (15 mm snout–vent length) to very large species (92 mm), and shape, particularly sin relative limb length. Five main morphological and environmental summary variables displayed strong phylogenetic signal. There was no clear relationship between body size and environmental niche, and this result persisted following phylogenetic correction. For most species, there was a better match between environment/habitat and body shape, but this relationship did not persist following phylogenetic correction. At a broad level, species fell into three broad groups based on environmental niche and body shape: 1) species in wet habitats with relatively long limbs, 2) species in arid environments with relatively short limbs (many of which are forward or backward burrowers) and 3) habitat generalist species with a conservative body shape. However, these patterns were not repeated within the four largest genera ? Crinia, Limnodynastes, Pseudophryne and Uperoleia. Each of these genera displayed a highly conservative anuran body shape, yet individual species were distributed across the full spectrum of Australian environments. Our results suggest that phylogenetic legacy is important in the evolution of body size and shape in Australian anurans, but also that the conservative body plan of many frogs works well in a wide variety of habitats.  相似文献   

15.
Recent studies of captive macaques have revealed considerable inter-species differences in dominance styles among females. In “egalitarian” species such as stumptail (Macaca arctoides) or tonkean macaques (M. tonkeana), social interactions are more symmetrical and less kin-biased than in “despotic” species such as Japanese (M. fuscata) or rhesus macaques (M. mulatta). Field observations of moor macaques (M. maurus), close relatives of tonkean macaques, suggest that tolerance during feeding characterizes their egalitarian dominance style in the natural habitat. Although it has been proposed that communal defense against other groups may be the main selective force in the evolution of egalitarian dominance style among females, few field data support this prediction. A game theory analysis showed that both an “egalitarian” strategy and a “despotic” strategy are possible evolutionarily stable strategies (ESS) under certain conditions. The difference in dominance styles might reflect the difference in ESS. This means that an egalitarian dominance style can emerge without strong between-group contest competition. A phylogenetic comparison among macaques suggests that despotic dominance styles very likely evolved from egalitarian dominance styles. In the future, primate socioecological studies should pay more attention to the evolutionary history of each species.  相似文献   

16.
A new sciaenid,Johnius (Johnieops) philippinus, is described from the Davao Gulf, Mindanao Island Philippines. It differs from all known species of the subgenus in the combination of 29–32 dorsal fin soft rays, 5–6 scales above and 10–13 scales below the lateral line, 10–12 lower gill rakers, a broadly rounded anterior snout margin (from dorsal aspect), large eyes (28–35% HL), a narrow interorbital space (23–28% HL) and well-developed pleural ribs on 11th vertebra. A synopsis of species included in the subgenusJohnieops is provided.  相似文献   

17.
Genetic variability and structure of nonindigenous vs native populations are compared for the Eurasian round goby Neogobius melanostomus and the tubenose goby Proterorhinus marmoratus, which both invaded Lake St. Clair of the North American Great Lakes about 1990. The round goby spread rapidly to all of the Great Lakes and the tubenose goby largely has been restricted to Lake St. Clair, with some recent range extension into western Lake Erie. Risk analyses may indicate whether genetic variability of colonizers is predictive of their relative invasive and establishment successes. The present investigation examined DNA sequence variation across the left domain of the mitochondrial DNA cytochrome b gene in round and tubenose gobies from Eurasian and Great Lakes locations. We also sequenced six additional Neogobius species (including the monkey N.␣fluviatilis, racer N. gymnotrachelus, and bigheadN. kessleri gobies that have been ‘on the move’ in Europe) and the knout goby Mesogobius batrachocephalus from the Black Sea in order to develop diagnostic genetic characters to identify them in case of future and/or undetected invasions and to delineate their phylogenetic relationships. Results show that a diverse number of haplotypes characterize round and tubenose goby populations from both North America and Eurasian sites, fitting a risk analysis prediction of high genetic variability in their successful introductions. Phylogenetic results indicate that the current genus Neogobius is paraphyletic and that the subgenusApollonia thus should be elevated to the level of genus, containingApollonia (N.) melanostomus (the round goby) andA. (N.) fluviatilis (the monkey goby). In addition, there appear to be two separate species of Proterorhinus marmoratus, a marine P. marmoratus Pallas 1814 in the Black Sea (matching the original type locality), and a ‘cryptic’ freshwater species in the Danube and Dnieper Rivers and probably other Eurasian freshwater habitats, as well as invasive in the Great Lakes. We suggest resurrecting the name P. semilunaris Heckel 1837 for the freshwater species (a taxon that was originally described from rivers draining into the Aegean Sea and the Danube River, but was later placed in synonymy with P. marmoratus). An erratum to this article is available at .  相似文献   

18.
A data set of LSU DNA sequences of mainly European Russula and Lactarius species was subjected to molecular phylogenetic analysis. Species could be allocated to six clades, with an unresolved phylogeny. One of these clades represents the genus Lactarius. The only analysed species of the section Archaeinae (Russula) was placed basal to both genera. Thus Lactarius appears to be derived from Russula. Russula was divided into four clusters, corresponding to the sections Plorantinae and Nigricantinae, subgenus Heterophyllidia including the section Foetentinae, and a cluster representing the remaining subgenera of the “Genuinae”. Even though the resulting groups can be considered as valid classificatory groups, species associations resulting from molecular analyses neither support the division of Russula into the subgenus Compacta (including the sections Nigricantinae, Plorantinae, and Archaeinae) and the “Genuinae” (including all remaining taxa), nor do they support previously proposed evolutionary lineages within the “Genuinae”. Ribosomal ITS DNA sequences of Russula species were analysed to achieve better infrageneric resolution. The results are discussed in relation to current classification systems and to what is known about the mycorrhizae formed by Russula species. While the systematic value attached to many macroscopic and microscopic sporocarp features was not supported by sequence data, mycorrhizal anatomy is in good correspondence with many of the results from the phylogenetic analysis.  相似文献   

19.
Pollen from 152 collections representing 16Pyrola species was examined with LM, SEM and TEM. The genusPyrola is stenopalynous in having tetrads and 3-colporoidate grains. However, a continuous and serial variation in the exine sculpture and the tetrad diameter (D) was revealed within the genus. Křísa's system ofPyrola (1971) was re-examined in the light of these palynological characters which may have a taxonomic significance, as well as the external morphology. P. minor (only member of the subgenusAmelia), which is characterized by having small (D=30–35 μm) pollen tetrads with verrucate sculpture must best be placed near sectionPyrola of the subgenusPyrola. P. faurieana must be segregated from sectionChlorantha and together withP. media placed intermediate between the subgenusAmelia and sectionPyrola of the subgenusPyrola based on their larger (D=ca. 40 μm) pollen tetrads with verrucate sculpture. Two series of sectionChlorantha excludingP. faurieana are differentiated in the exine sculpture. Therefore, they are regarded as the distinct taxonomic groups. SectionScotophylla is characterized by having psilate sculptured pollen tetrads, which indicates that its sectional rank is sufficiently asserted. The evolutionary trend in the exine sculpture from verrucate through rugulate to psilate is suggested withinPyrola.  相似文献   

20.
Seed and pollen morphology were studied by light microscopy and scanning electron microscopy in 39 North and Central American species of Houstonia (including Hedyotis, but excluding Oldenlandia). Chromosome counts were obtained for eight taxa, of which five lacked previous chromosome data. A chromosome number of n = 17 for Houstonia gracilis is a new base number for the genus. Seed external morphology in the genus is very diverse, including variation in compression, margins, testa surfaces, and elaboration of ventral cavities or depressions and hilar ridges or their absence. Three types of pollen apertures are recognized: colporate with type A os, colpororate, and colporate with type B os, the last the most advanced type, occurring in H. caerulea and related species. The 39 species are arranged in twelve groups, based on correlation of seed, pollen, and chromosome data. Geographic distribution provides supplementary evidence for the distinctness and integrity of the six principal groups each composed of 2–9 species. Five of the six minor groups each with one species need chromosome data to facilitate future taxonomic decisions. Chromosome numbers of x = 6, 7, 8, 9, 10, 11, 13, and 17 are now known in this genus, and phylogenetic implications of the combined data are discussed.  相似文献   

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