广东省罗坑自然保护区鳄蜥对溪沟林型的选择

2006年5—9月在广东省罗坑自然保护区,对大竹园管护站所辖区域内鳄蜥栖息溪沟的林型进行了调查,采用选择指数法研究了鳄蜥对溪沟林型的选择性。共调查了154只鳄蜥的生境特征,并对5种溪沟林型(常绿阔叶林、针阔混交林、针叶林、竹林和灌草)进行了样方调查。结果表明:鳄蜥对溪沟林型的选择是非随机的,偏好常绿阔叶林,对竹林接近于随机选择,回避其它林型;鳄蜥选择常绿阔叶林可能与其植被盖度较高、涵养水源能力强以及土壤有机质含量高有关。建议加强对常绿阔叶林的保护工作,以更好地保护鳄蜥。     

广东罗坑自然保护区饲养鳄蜥的求偶和交配行为

半自然条件下,通过直接观察及影像分析法对鳄蜥(Shinisaurss crocodilurus)的求偶和交配行为进行了研究.共记录了20种与鳄蜥求偶和交配有关的行为,其求偶和交配行为的一般模式为:(1)炫耀;(2)接近;(3)舔舐;(4)咬颈;(5)环抱;(6)交媾;(7)分离.该行为过程的持续时间分别为(157.29±33.81)s、(15.57±1.59)8、(10.86±3.05)s、(169.28±31.99)s、(66.14±16.08)s、(2 417.14±229.30)s和(26.86±9.15)s.鳄蜥的婚配制度可能是多雄多雌的婚配制,其求偶和交配模式与其近缘类群相似.     

半自然条件下鳄蜥的管理

2005年7～10月我们将人工饲养鳄蜥（3条幼蜥、1条亚成蜥、5条成蜥）置于半放归栖息地进行圈养.半放归栖息地结合野外鳄蜥的生境,在半自然圈养过程中对鳄蜥进行分组管理,人工饲养的鳄蜥出现了野外鳄蜥的种群活动节律.结果表明：9月幼蜥树栖达10.38%,10月鳄蜥以在穴为主;不同年龄的鳄蜥,各种行为的时间分配无显著差异（P＞0.05）,体现了野生鳄蜥遗传特征.本文还对鳄蜥的疾病防治进行了初步探讨.     

半自然状态下鳄蜥活动时间分配的初步研究

在半自然的条件下采用瞬时扫描法对鳄蜥活动时间分配进行了初步的研究,结果表明:在池养鳄蜥的活动时间分配中,静栖占69·09%,在穴占28·82%,移动占0·80%,捕食占0·28%,晒太阳占0·44%,其它占0·58%;比较了不同性别鳄蜥的活动时间分配,其中雄性鳄蜥用在移动的时间占1·15±1·22%,雌性为0·45±1·00%,经过单因素检验显示其差异显著(P<0·01),其它行为活动时间分配差异不显著;初步比较了不同生境中鳄蜥的行为差异,结果显示鳄蜥在池养的条件下弹性行为的表现频次正在下降。     

Molecular phylogeny of Stentor (Ciliophora: Heterotrichea) based on small subunit ribosomal RNA sequences

To determine the phylogenetic position of Stentor within the Class Heterotrichea, the complete small subunit rRNA genes of three Stentor species, namely Stentor polymorphus, Stentor coeruleus, and Stentor roeseli, were sequenced and used to construct phylogenetic trees using the maximum parsimony, neighbor joining, and Bayesian analysis. With all phylogenetic methods, the genus Stentor was monophyletic, with S. roeseli branching basally.     

广东省曲江县发现鳄蜥

报道了首次发现于广东的鳄蜥的形态结构特征,并将它与广西的鳄蜥进行了比较。     

广西桂平市鳄蜥种群及栖息地现状的分析研究

2004年7月,对广西桂平市鳄蜥种群及其栖息地进行了调查,并首次采用量化指标对鳄蜥栖息的回水塘进行了分析。结果表明：桂平市鳄蜥分布区已破碎成白沙坑、牛头坳和黄凉冲、大藤峡碧滩段三个片段,分布区面积从58．39km^2减小至16．14km^2。鳄蜥种群数量约为150只。通过主成分分析发现,鳄蜥栖息回水塘的长度、宽度、水深、塘底组成、水温、栖枝类型和栖枝高度是影响鳄蜥选择回水塘的主要因子,而海拔、栖枝直径、水流速度的影响不大。鳄蜥倾向栖息于常绿阔叶林生境中,对溪沟的坡向和沟型选择不明显。     

Molecular Systematics of Selene (Perciformes: Carangidae) Based on Cytochrome b Sequences

The marine fishes of the genus Selene are morphologically unique, although little is known about how these species are related to other members of the family Carangidae (Perciformes). In addition, questions remain about the potential validity of two putative species and how species groups with unique body forms within Selene are related. We used DNA sequences of the mitochondrial cytochrome b gene to reconstruct the phylogeny of the seven species of Selene along with five additional species of carangids. Maximum-likelihood and maximum-parsimony analyses were used to examine the sequence data and both phylogenetic methods were compared. Maximum-likelihood produced a monophyletic Selene, whereas parsimony analyses did not. Both maximum-likelihood and maximum-parsimony produced similar support for species groups within Selene. Maximum-likelihood produced two monophyletic subgroups within the genus Selene, the "long-finned" and "short-finned" Selene. Maximum-parsimony produced the same monophyletic "long-finned" group but a paraphyletic "short-finned" group. Both analyses confirm that S. brownii and S. setapinnis are distinct species, expunging the question of conspecificity. The phylogenetic placement of the most basal taxon within Selene, S. orstedii, was problematic and differed among analyses. More data are needed to resolve with confidence its correct phylogenetic placement and, thus, the monophyly of the genus Selene.     

鳄蜥的两性异形

通过比较鳄蜥的体型与头部大小等特征的差异,研究了鳄蜥的两性异形情况.结果表明:性成熟鳄蜥个体体色差异显著,成年雄性头胸部腹面呈鲜红色或浅蓝色,而雌性为浅黄色或淡红色;成年雄性头部显著大于成年雌性(头长(HL),P＜0.001;头宽(HW),P＜0.001),成年雌性腹部长(AL)显著大干成年雄性(P=0.018);而成...     

Urochordates are monophyletic within the deuterostomes

Understanding the phylogenetic relationships of the three major urochordate groups within the deuterostomes is central to understanding the evolution of the chordates. We have prepared a detailed phylogenetic analysis of urochordates based on comparisons of 10 new urochordate 18S ribosomal DNA sequences with other urochordate sequences in GenBank. Maximum parsimony, neighbor-joining, minimum evolution, and maximum likelihood analyses of this large urochordate data set are consistent with a topology in which the urochordates are monophyletic within the deuterostomes and there are four separate clades of urochordates. These four distinct clades--styelid + pyurid ascidians, molgulid ascidians, phlebobranch ascidians + thaliaceans, and larvaceans--are mostly consistent with traditional morphological hypotheses and classifications. However, we find that the ascidians may not be a monophyletic group (as they have been considered traditionally) but instead appear paraphyletic. Another disparity with traditional classification is that the thaliaceans do not form a separate urochordate clade but rather cluster with the phlebobranch ascidians. Larvaceans have long branch lengths, which can be problematic for molecular phylogenetic methods, and their position within the urochordates cannot be unequivocally determined with 18S rDNA. This is important because the tadpole morphology of larvacean and ascidian larvae is the key trait of interest that distinguishes urochordates as chordates. Nevertheless, the present data set resolves at least three clades of urochordates and suggests strongly that urochordates form a monophyletic clade within the deuterostomes.     

鳄蜥的食物识别机制

鳄蜥(Shinisaurus crocodilurus)食物识别机制的研究,对进一步了解鳄蜥的捕食行为和生态学习性有重要意义。使用棉棒分别沾上去离子水、香水、黄粉虫(Tenebriomolitor L.)和蚯蚓(Pheretima sp.)的气味(蚯蚓和黄粉虫处死后绞碎以便于棉花棒蘸上),观察11只鳄蜥对4种化学刺激的反应,每个个体对每种刺激均进行24次实验重复。实验结果显示：鳄蜥对4种刺激均有反应,对黄粉虫和蚯蚓刺激的舔舌次数显著高于香水和去离子水的舔舌次数(Wilcoxon test,所有P<0.001),表明鳄蜥能检测以及识别控制刺激和食物刺激。再又对鳄蜥进行4种处理实验：(A)空白对照;(B)蚯蚓气味;(C)密封着的活蚯蚓;(D)活蚯蚓。每个个体每种处理均进行5次实验。结果显示：鳄蜥在不同处理下的行为持续时间、探究频次和攻击频次有显著差异(Friedman test,所有P<0.001)。鳄蜥在仅有视觉刺激出现的处理C以及既有化学刺激又有视觉刺激的处理D比仅有化学刺激的处理B在持续时间、探究频次和攻击频次上显著要高（所有P<0.001）。在无视觉刺激的条件下,鳄蜥在处理B的行为持续时间以及探究频次均显著高于处理A 的（所有P<0.001）;而在视觉信息相同的条件下,鳄蜥在处理D中仅行为持续时间显著高于处理C（Z=3.95, P<0.001）,而探究频次以及攻击频次无显著差异（前者Z=1.53, P=0.13;后者Z=1.10, P=0.27）。结果表明鳄蜥主要利用视觉捕食,化学感觉有辅助作用。鳄蜥这种食物识别机制可能与捕食模式和种系发生有关,也可能受食物的影响。     

Molecular phylogeny of Sinocyclocheilus (Cypriniformes: Cyprinidae) inferred from mitochondrial DNA sequences

More than 10 species within the freshwater fish genus Sinoncyclocheilus adapt to caves and show different degrees of degeneration of eyes and pigmentation. Therefore, this genus can be useful for studying evolutionary developmental mechanisms, role of natural selection and adaptation in cave animals. To better understand these processes, it is indispensable to have background knowledge about phylogenetic relationships of surface and cave species within this genus. To investigate phylogenetic relationships among species within this genus, we determined nucleotide sequences of complete mitochondrial cytochrome b gene (1140 bp) and partial ND4 gene (1032 bp) of 31 recognized ingroup species and one outgroup species Barbodes laticeps. Phylogenetic trees were reconstructed using maximum parsimony, Bayesian, and maximum likelihood analyses. Our phylogenetic results showed that all species except for two surface species S. jii and S. macrolepis clustered as five major monophyletic clades (I, II, III, IV, and V) with strong supports. S. jii was the most basal species in all analyses, but the position of S. macrolepis was not resolved. The cave species were polyphyletic and occurred in these five major clades. Our results indicate that adaptation to cave environments has occurred multiple times during the evolutionary history of Sinocyclocheilus. The branching orders among the clades I, II, III, and IV were not resolved, and this might be due to early rapid radiation in Sinocyclocheilus. All species distributed in Yunnan except for S. rhinocerous and S. hyalinus formed a strongly supported monophyletic group (clade V), probably reflecting their common origins. This result suggested that the diversification of Sinocyclocheilus in Yunnan may correlate with the uplifting of Yunnan Plateau.     

Molecular systematics of marsupials based on the rRNA 12S mitochondrial gene: the phylogeny of didelphimorphia and of the living fossil microbiotheriid Dromiciops gliroides thomas

Nucleotide sequence data from the mitochondrial 12S rRNA gene were used to evaluate the phylogenetic relationships among the major groups of didelphimorph and paucituberculatan marsupials from South America, the microbiotheriid Dromiciops gliroides, and representatives of four orders of Australasian marsupials. Based on approximately 800 bp in 18 genera, we conclude that the didelphids constitute a monophyletic group with large-sized forms differentiated from small opossums, while Caluromys constitutes the sister taxon to didelphids. The peramelid Isoodon was recovered as the sister taxon to the paucituberculatans Caenolestes and Rhyncholestes, although it is in an uncertain phylogenetic position within the marsupial tree. Dromiciops was recovered as a well-differentiated lineage from South American opossums within the Australidelphian radiation of metatherians that include dasyurid, diprotodontian, and notoryctemorph marsupials.     

Berkleasmium crunisia sp. nov. and its phylogenetic affinities to the Pleosporales based on 18S and 28S rDNA sequence analyses

Berkleasmium crunisia sp. nov. is described from a decaying rachis of Calamus sp. (Arecaceae) from Khuan Ka Long, Satun Province, Thailand. This Berkleasmium species differs morphologically from other species in possessing subtending cells and larger conidia. The phylogenetic relationship of the genus Berkleasmium among sexual ascomycetes also was examined. Sequence analyses from 18S, 28S and ITS-5.8S rDNA were analyzed phylogenetically under maximum parsimony, Bayesian and neighbor joining criteria. Phylogenies revealed that Berkleasmium is not monophyletic. Berkleasmium micronesicum and B. nigroapicale are related to Westerdykella cylindrica and Sporormia australis, which are members of the family Sporormiaceae (Pleosporales). Other species, including our new taxon, appear to share phylogenetic affinities with other anamorphic fungi, whose classification within the Pleosporales is still obscure. Analyses of 18S, 28S, ITS (+5.8S) rDNA and combined (18S+28S) gene sequences fail to give sufficient phylogenetic resolution within the Pleosporales.     

Molecular evidence for novel planctomycete diversity in a municipal wastewater treatment plant

We examined anoxic and aerobic basins and an anaerobic digestor of a municipal wastewater treatment plant for the presence of novel planctomycete-like diversity. Three 16S rRNA gene libraries were constructed by using a 16S rRNA-targeted universal reverse primer and a forward PCR primer specific for Planctomyces: Phylogenetic analysis of 234 16S rRNA gene sequences defined 110 operational taxonomic units. The majority of these sequences clustered with the four known genera, Pirellula (32%), Planctomyces (18.4%), Gemmata (3.8%), and Isosphaera (0.4%). More interestingly, 42.3% of the sequences appeared to define two distantly separated monophyletic groups. The first group, represented by 35.5% of the sequences, was related to the Planctomyces group and branched as a monophyletic cluster. It exhibited between 11.9 and 20.3% 16S rRNA gene sequence dissimilarity in comparisons with cultivated planctomycetes. The second group, represented by 6.8% of the sequences, was deeply rooted within the Planctomycetales tree. It was distantly related to the anammox sequences (level of dissimilarity, 20.3 to 24.4%) and was a monophyletic cluster. The retrieved sequences extended the intralineage phylogenetic depth of the Plantomycetales from 23 to 30.6%. The lineages described here may have a broad diversity of undiscovered biochemical and metabolic novelty. We developed a new 16S rRNA-targeted oligonucleotide probe and localized members of one of the phylogenetic groups using the fluorescent in situ hybridization technique. Our results indicate that activated sludge contains very diverse representatives of this group, which grow under aerobic and anoxic conditions and even under anaerobic conditions. The majority of species in this group remain poorly characterized.     

Phylogenetic position of Phthiraptera (Insecta: Paraneoptera) and elevated rate of evolution in mitochondrial 12S and 16S rDNA

Phthiraptera (chewing and sucking lice) and Psocoptera (booklice and barklice) are closely related to each other and compose the monophyletic taxon Psocodea. However, there are two hypotheses regarding their phylogenetic relationship: (1) monophyletic Psocoptera is the sister group of Phthiraptera or (2) Psocoptera is paraphyletic, and Liposcelididae of Psocoptera is the sister group of Phthiraptera. Each hypothesis is supported morphologically and/or embryologically, and this problem has not yet been resolved. In the present study, the phylogenetic position of Phthiraptera was examined using mitochondrial 12S and 16S rDNA sequences, with three methods of phylogenetic analysis. Results of all analyses strongly supported the close relationship between Phthiraptera and Liposcelididae. Results of the present analyses also provided some insight into the elevated rate of evolution in mitochondrial DNA (mtDNA) in Phthiraptera. An elevated substitution rate of mtDNA appears to originate in the common ancestor of Phthiraptera and Liposcelididae, and directly corresponds to an increased G+C content. Therefore, the elevated substitution rate of mtDNA in Phthiraptera and Liposcelididae appears to be directional. A high diversity of 12S rDNA secondary structure was also observed in wide range of Phthiraptera and Liposcelididae, but these structures seem to have evolved independently in different clades.     

A phylogeny of the fish family Sparidae (porgies) inferred from mitochondrial sequence data

The porgies (Sparidae) comprise a diverse group of neritic fishes with a broad geographic distribution. We used mitochondrial DNA sequences from partial 16S ribosomal RNA and cytochrome b genes to reconstruct the phylogenetic history of these fishes. Sequences from 38 sparid species, 10 species in outgroups closely related to sparids, seven basal percoid species, and a non-perciform outgroup species were analyzed with parsimony and maximum likelihood. The Sparidae were monophyletic with the inclusion of Spicara, which is currently placed in the Centracanthidae. The genera Spicara, Pagrus, and Pagellus, were not monophyletic indicating a need for revision. Two main sparid lineages were recovered in all analyses, but the previously proposed six sparid subfamilies (Boopsinae, Denticinae, Diplodinae, Pagellinae, Pagrinae, and Sparinae) were not monophyletic. This suggests that dentition and feeding modes, upon which these subfamilies are based, were independently derived multiple times within sparid fishes. There was no evidence from the 16S or combined analyses for a monophyletic Sparoidea.     

基于ITS序列对中国簇毛黄耆亚属（黄耆属）系统学问题的初步研究

测定了簇毛黄耆亚属（Pogonophace)4组8种和外类群Caragana roborovskyi的ITS序列,从GenBank中调出相关12属47种的ITS序列,组成数据距阵,应用PAUP程序中的最大简约法构建了系统发育树状图。扁荚组（Sect.Sesbanella)与亚属其余类群在系统树上处于不同的分支,亲缘关系较远这个亚属不是一个单系类群;膨果组（Sect.Bibracteola)。背扁组（Sect.Phyllolobium)和袋果组（Sect.Trichostylus)作为一个单系类群能得到ITS序列的支持,但与分组以及膨果组下系的划分都得不到ITS序列分析的支持。     

Phylogeny of colletid bees (Hymenoptera: Colletidae) inferred from four nuclear genes

Colletidae comprise approximately 2500 species of bees primarily distributed in the southern continents (only two colletid genera are widely distributed: Colletes and Hylaeus). Previously published studies have failed to resolve phylogenetic relationships on a worldwide basis and this has been a major barrier to the progress of research regarding systematics and evolution of colletid bees. For this study, data from four nuclear gene loci: elongation factor-1alpha (F2 copy), opsin, wingless, and 28S rRNA were analyzed for 122 species of colletid bees, representing all subfamilies and tribes currently recognized; 22 species belonging to three other bee families were used as outgroups. Bayesian, maximum likelihood, and parsimony methods were employed to investigate the phylogenetic relationships within Colletidae and resulted in highly congruent and well-resolved trees. The phylogenetic results show that Colletidae are monophyletic and that all traditionally recognized subfamilies (except Paracolletinae) are also strongly supported as monophyletic. Our phylogenetic hypothesis provides a framework within which broad questions related to the taxonomy, biogeography, morphology, evolution, and ecology of colletid bees can be addressed.