SYSTEMATIC STATUS AND PHYLOGENETIC RELATIONSHIPS OF THE FRESHWATER GENUS BALBIANIA (RHODOPHYTA)

The freshwater rhodophyte Balbiania investiens (Lenormand) Sirodot was collected as an epiphyte of Batrachospermum in small streams in England, Ireland, and Germany. Unialgal cultures and field collections of Balbiania were analyzed in terms of their morphology, ultrastructure, and the DNA sequences of the genes coding for the large subunit of ribulose-1,5-bisphosphate carboxylase/oxygenase ( rbc L) and 18S ribosomal RNA (rRNA), as well as the first internal transcribed spacer region (ITS1) of the rRNA genes. One of the major distinguishing features of this genus is the production of spermatangia on the tips of specialized, elongate cells. The spermatangia are cut off in a cluster together with similar nonspermatangial cells that are packed with starch granules. The only other rhodophyte genus with this feature is Rhododraparnaldia ; the two genera are differentiated from each other by the pattern of branching, substratum of attachment, and type of diploid phase. In the parsimony and distance trees inferred from the two gene sequences as well as in a combined parsimony tree, Balbiania and Rhododraparnaldia grouped together on a well-supported branch separate from other taxa of the Batrachospermales, Acrochaetiales, Nemaliales, and Palmariales. However, the two genera are positioned within a clade containing the last three orders. Based on these findings, it is clear that the genus Balbiania is a valid taxon and that it is phylogenetically associated with Rhododraparnaldia. A new order is proposed, the Balbianiales. The two specimens of Balbiania analyzed from England and Germany have identical sequences for all regions of DNA analyzed.     

PHYLOGENETIC RELATIONSHIPS OF SCOTUSSA AND LEIOTETTIX (ORTHOPTERA: ACRIDIDAE)

Abstract— A cladistic analysis of the South American grasshopper genera Scotussa and Leiotettix was performed in order to test the monophyly of these genera. Eurotettix, Chlorus and the Dichroplus bergi species group were included as terminal taxa. The genus Atrachelacris was used to root the tree. Twenty-nine characters from external morphology, male genitalia and female ovipositor were used in the analysis. In order to test for association between the structural change that occurred in the ovipositor valves of Scotussa and the functional change of the oviposition habits, the data matrix was partitioned and two analyses were performed. Characters from the female ovipositor were excluded from the data set used in the first analysis and another analysis was performed where all the characters were included in the analysis. Information on oviposition habits was then mapped on the cladogram, to determine the transformation for performance. Both analyses yielded only one most parsimonious tree and produced congruent results, confirming the monophyly of Leiotettix and Scotussa and corroborating their close relationship. Characters from the female ovipositor valves were informative not only at the species level but also at higher levels in the cladogram. The results also support the hypothesis of association between the structural change that occurred in the ovipositor valves of Scotussa with the functional change in the oviposition habits. However, this association did not seem to be correlated with the adaptive radiation in the genus.     

基于16S rDNA序列探讨十种臂尾轮虫的系统关系和分类地位

通过对角突臂尾轮虫、尾突臂尾轮虫、裂足臂尾轮虫、剪形臂尾轮虫、方形臂尾轮虫、壶状臂尾轮虫、红臂尾轮虫、镰肜臂尾轮虫、萼花臂尾轮虫和十指臂尾轮虫等十种臂尾轮虫和大肚须足轮虫的线粒体16s rDNA进行扩增和序列测序,结合Genebank 中十指臂尾轮虫的16S rDNA序列,使用MAGE软件构建了NJ(neighbor-joining method)树,使用mrbayes软件构建了贝叶斯树,探讨了十种臂尾轮虫之间的系统关系.结果表明,本研究所涉及的轮虫16S rDNA序列差异百分比均值为14.6%,可作为分子标记应用于轮虫属内种间系统关系研究;系统树均支持将十指臂尾轮虫、裂足臂尾轮虫隶属于臂尾轮属;壶状臂尾轮虫和红臂尾轮虫是两个独立的种.此外,还依据16S rDNA序列变异百分比推测了十种臂尾轮虫的分化时间.     

EARLIEST MEGAFOSSIL EVIDENCE OF FAGACEAE: PHYLOGENETIC AND BIOGEOGRAPHIC IMPLICATIONS

Fossil evidence of Fagaceae from the Paleocene/Eocene boundary of western Tennessee is described and discussed. These fossils include a newly discovered pistillate inflorescence and dispersed fruits of subfamily Castaneoideae as well as a taxon that resembles modern trigonobalanoids (pistillate inflorescences and dispersed mature fruits). Fossil staminate catkins with fagaceous pollen, which we suggest may be conspecific with the trigonobalanoid infructescences, are also found at the locality. Two distinct types of fagaceous leaves are present at the locality. The reproductive structures are the oldest megafossils unequivocally assignable to Fagaceae and represent the oldest remains of subfamily Fagoideae and the oldest megafossil remains of Castaneoideae. In addition, the fossils provide insights into the chronology of diversification, biogeography, and phylogeny of Fagaceae. The trigonobalanoid remains may also provide insights into the timing and circumstances of the evolution of wind pollination in Fagaceae.     

盔甲鱼亚纲(无颌类)的系统发育关系

基于对53个形态学特征的讨论,首次开展了无颌类儒甲鱼亚纲的简约性分析,获得了3 个最简约的分支图,其步长为126,一致性指数为0．508,保留指数为0．801。在此基础上,修订了盔甲鱼亚纲的分类。研究结果表明,志留纪兰多维列世至温洛克世的汉阳鱼类、修水鱼类和大庸鱼类属于盔甲鱼亚纲的基干类群。在其余盔甲鱼类中,识别出3个大的单系类群, 分别是真盔甲鱼目、多鳃鱼目和华南鱼目。在盔甲鱼亚纲中,头甲背窗的起源至少发生了两次,一次在多鳃鱼目支系中,另一次在华南鱼目支系中。基于背窗特征而建立的大窗鱼类并不是一个单系类群。盔甲鱼类的年代分布指示该类群的两次辐射演化,分别是兰多维列世特列奇期基干盔甲鱼类和真盔甲鱼目的辐射演化,和早泥盆世洛霍考夫期多鳃鱼目和华南鱼目的辐射演化。     

EXTINCT TRANSITIONAL FAGACEAE FROM THE OLIGOCENE AND THEIR PHYLOGENETIC IMPLICATIONS

Fruits, catkins, and associated leaves of at least two extinct trigonobalanoid taxa have been discovered at an Oligocene fossil plant locality rich in fagaceous remains. These fossils exhibit a mosaic of fruit and pollen characters found in the two extant subfamilies Castaneoideae and Fagoideae of Fagaceae. Comparison with cladograms based on modern taxa suggests that these extinct taxa were similar to the ancestors of subfamily Fagoideae and may have been intermediate between Fagus and the modern trigonobalanoid genera. Pollen types isolated from the fossil staminate catkins provide unique character states that are transitional between modern pollen types in Fagaceae and are important in understanding the evolution of exine micromorphology within the family. This analysis provides a striking example of the use of character data from fossils to determine character-state adjacency prior to polarization of characters using outgroup comparison. Because of the mosaic nature of their character complexes, these fossils support monophyly in both the family Fagaceae and the subfamily Fagoideae. In addition, the occurrence of trigonobalanoid fossils in the Oligocene of North America has interesting biogeographic implications and provides insights into the nature of North American Fagaceae during the Tertiary.     

PHYLOGENETIC RELATIONSHIPS OF THE CAMAENIDAE (PULMONATA: STYLOMMATOPHORA: HELICOIDEA)

The land snail family Camaenidae is defined by the lack of characters,such as dart sac and glands, which are present in related familiesAlthough the Camaenidae is regarded as monophyletic, no synapomorphiesunite the family It is possible that the Camaenidae is para-or polyphyletic This was investigated using a cladistic analysisof the super-family Helicoidea which was based on anatomicalcharacters from previous studies by Tilher (1989) Camaenidaewas split into two geographical groups (American and Australasian).Successive weighting generated a single most parsimonious cladogram(length 198, c.i. 0.61, r.i. 0.64), which suggested that theCamaenidae is a polyphyletic taxon. Evidence from this analysisdemonstrated that the American component of the Camaenidae isclosely related to the Hehcidae and Helminthoglyptidae, andthe Australasian component is sister group to the Bradybaenidae ^*Current address Department oJ Zoology. James Cook Universityof North Queensland. Townsville. Queensland 4811, Australia (Received 30 July 1994; accepted 20 June 1995)     

同宗配合蜜环菌与欧美异宗配合蜜环菌狭义种的分子系统学关系

从亚洲、欧洲和北美收集18个蜜环菌狭义种菌株,PCR扩增其rDNA的IGS和ITS区域,用AluI、HaeIII、HinfI和TagI四种限制性内切酶进行酶切,同时用随机扩增微卫星(RAMS)多态性,对蜜环菌狭义种的进行了遗传多样性和分子系统学分析。结果蜜环菌狭义种的IGS和ITS-RFLP类型比以前报道的更多,亚洲、欧洲和北美菌株都具有比较明显的特征片段,通过ITS和IGS图谱可将三个大陆的菌株区分开,其中IGS-HinfI图谱能完全区分3个大陆的菌株。RFLP数据的系统学分析表明,该种存在明显的大陆遗传分化,亚、欧、北美的群体分属三个相互独立的进化系,北美群体IGS变异程度较小,ITS变异程度极高;而欧洲群体IGS的变异程度较大,多态性高,ITS变异程度非常小。RAMS系统分析表明,中国、日本和非洲的同宗配合蜜环菌属于一个系统发育系,该发育系同欧洲和北美的异宗配合种的两个发育系分属3个不同的独立进化分支。据此建议欧洲和北美的异宗配合蜜环菌应作为蜜环菌的两个亚种。     

CHLOROPLAST DNA EVOLUTION AND PHYLOGENETIC RELATIONSHIPS IN CLARKIA SECT. PERIPETASMA (ONAGRACEAE)

Restriction-site analysis of chloroplast DNA in Clarkia sect. Peripetasma (Onagraceae) was done to test previously proposed phylogenetic models. One hundred nineteen restriction-site mutations were identified among the nine species using 29 restriction enzymes, and these were used to construct rooted most parsimonious trees (Wagner and Dollo). A chloroplast DNA evolutionary clock could not be statistically rejected. Branch points of this tree were statistically tested by Felsenstein's bootstrap method. This tree 1) provided an unambiguous and detailed genealogical history for the section, 2) verified a previous partial phylogenetic model for the section based on gene duplications and differential silencing, 3) provided details of the phylogenetic model not inferred or expected based on morphology and reproductive isolation, and 4) indicated that morphology evolves at markedly different rates within and between lineages in the section.     

COMPARATIVE MORPHOLOGY AND TAXONOMIC STATUS OF GRACILARIOPSIS (GRACILARIALES,RHODOPHYTA)1

The vegetative organization and reproductive development of Gracilariopsis lemaneiformis (Bory) Dawson, Acleto et Foldvik [including Gracilaria sjoestedtii Kylin] were investigated. Our observations on spermatangial development and post-fertilization features establish that Gracilariopsis Dawson is distinct at the generic level from Gracilaria Greville, and ice propose the resurrection of Gracilariopsis Dawson as a result. Spermatangial parent cells of Gracilariopsis are superficial, initiated in pairs or groups of three by concavo-convex longitudinal and transverse divisions. Each spermatangial parent cell cuts off a single, colorless spermatangium distally by a transverse division. The female reproductive apparatus consists of a supporting cell that bears a two-celled carpogonial branch flanked by two sterile branches, as in Gracilaria. Likewise, up to six sterile cells fuse with the carpogonium after fertilization to produce a primary fusion cell that generates the gonimoblasts; however, a secondary fusion cell is absent. Inner gonimoblast cells unite with cytologically modified cells of the inner pericarp by means of secondary pit-connections. Tubular nutritive cells are absent. The gonimoblast consists of a central sterile tissue interconnected throughout by secondary pit-connections surmounted by a fertile layer composed of carposporangia aligned in straight chains. The distribution of Gracilariopsis is extended to Western Europe.     

TAXONOMIC STATUS OF

Association of Cattle Egrets Bubulcus ibis with large herbivores is well documented, but there are few records of their association with large birds. Here we describe the first-known records of foraging interactions between Shoebill Balaeniceps rex and Cattle Egrets. The observations were made at the Malagarasi-Muyovozi Ramsar Site in western Tanzania. Small flocks of egrets approached and foraged within 5 m of a Shoebill, which was sometimes forced to move from its hunting pool and by doing so it likely flushed more prey for egrets. Interactions occurred almost exclusively in the driest months, which suggested that prey were more difficult to locate by egrets during this period. The Shoebill inhabits inaccessible swamps and is a rare species with low density throughout its range. It is therefore possible that egret–Shoebill associations, in addition to being infrequent and highly seasonal, may have gone unnoticed.     

PHYLOGENETIC RELATIONSHIPS AMONG THE CHROMISTA: A REVIEW AND PRELIMINARY ANALYSIS

Abstract— It is now well established that the algae do not constitute a monophyletic group. A number of brown and golden algae are related to various heterotrophic protists, which have recently been characterized and described as a kingdom, the Chromista. The kingdom was defined primarily by two ultrastructural features: the presence of tubular, tripartite hairs (mastigonemes) on the surface of at least one flagellum, and the presence of a chloroplast endoplasmic reticulum. This included the watermoulds which, although they lack chloroplasts, do have mastigonemes. In addition, a number of heterotrophic flagellates also possess mastigonemes and should therefore be considered in the determination of interrelationships. This paper presents a cladistic analysis that focuses on 79 ultrastructural, cytological and biochemical characters. The unpigmented taxa appear at the base of the cladogram, suggesting a single origin for the chromophytic chloroplast. The crytomonads and Eustigmatophyta, usually considered primitive taxa, are sister to all the chrysophycean taxa which, with the exception of two monotypic genera and the Sarcinochrysidales, are monophyletic. The Prymnesiophyta, Bacillariophyta and Phaeophyta form a monophylectic group.     

短吻贫齿龙(双孔亚纲:海龙目):头后骨骼及系统关系研究

短吻贫齿龙是根据一保存较完整的头骨和下颌标本建立的;标本采自贵州关岭地区三叠系法郎组灰岩。对其头后骨骼进行了详细描述。短吻贫齿龙在肩带的乌喙骨和间锁骨及腰带的肠骨显示了与众不同的特征,例如:紧靠肩臼后方乌喙骨有一明显的凹,间锁骨后半部比前部要窄很多,及肠骨背突末端加宽等。头骨进一步细修表明,其中一些部位需要进行重新记述。依据头后骨骼和头骨中的新信息,对短吻贫齿龙的特征作了修订。系统关系分析表明,贫齿龙是个askeptosaurid,其下颌宽大于长的反关节突和肱骨缩小的三角-胸大肌嵴表明它与产自瑞士和意大利的Askeptosaurus关系最近。     

ULTRASTRUCTURE AND PHYLOGENETIC RELATIONSHIPS OF CHAETOPELTIDALES ORD. NOV. (CHLOROPHYTA,CHLOROPHYCEAE)1

Vegetative cells and zoospores of Hormotilopsis gelatinosa Trainor & Bold, H. tetravacuolaris Arce & Bold, Planophila terrestris Groover & Hofstetter, and Phyllogloea fimbriata (Korchikov) Silva were examined by transmission electron microscopy. All cells had pyrenoids traversed by cytoplasmic channels. Zoospores were quadriflagellate and had essentially cruciate flagellar apparatuses. Scales were present on free-swimming zoospores. These features are essentially identical to those of Chaetopeltis sp. and are dissimilar to those of other described green algae. The new order Chaetopeltidales is created to accommodate the genera Chaetopeltis, Hormotilopsis, Planophila sensu Groover & Hofstetter, Phyllogloea, Dicranochaete, and Schizochlamys, organisms previously scattered among the orders Tetrasporales, Chloro-coccales, Chlorosarcinales, and Chaetophorales. Members of the order are closely related to the ancestral chlorophycean flagellate genus Hafniomonas, may be ancestral with respect to other Chlorophyceae, and may also be closely related to the ulvophycean order Ulotrichales.     

TAXONOMIC STATUS OF BARK BEETLES (COLEOPTERA,CURCULIONIDAE)

许多学者将小蠹作为象虫总科Curculionoidea中一个独立的科Scolytidae,而目前国际上普遍认为小蠹为象虫科Curculionidae中的一个亚科,即小蠹亚科Scolytinae.Erichson在1842年即提出了小蠹为象虫科的一个亚科,20世纪以R.A.Crowson为代表的学者对此观点表示支持并进行了较为严谨的科学论证,而以S.L.Wood为代表的另外一些学者则坚持小蠹的科级地位,我国学者蔡邦华、殷惠芬等一直沿用该分类系统.近20年来,国际上许多学者通过对小蠹类昆虫的成虫和幼虫外部特征的深入研究,以及支序系统学和分子生物学等一些最新结果,普遍认为小蠹类昆虫应为象虫科的一个业科,这一观点已被国际上广泛接受.本文全面介绍了小蠹分类研究的历史及新的研究进展,并提出和建议采用“小蠹亚科”这一分类地位,与象虫亚科并列,均隶属于象虫科.