栉齿类新亚科Veteranellinae subfam.nov.——兼论壳饰在古栉齿亚纲的分类意义

研究古栉齿亚纲(Palaeotaxodonta)的详细分类,是一个比较困难的课题,因为在这一亚纲,科以上分类单元之间,栉齿排布、韧带型式、外套湾特征及壳质微细构造类型等分类标志,尚较明显地有些差异,但在科以下的分类单元     

各地钉螺α-磷酸甘油脱氢酶和酯酶同功酶变异的研究

以往钉螺(Oneomelania)的分类沿用形态学的方法。但根据形态特点,对钉螺种的分类,往往可靠性不大(Davis 1967)。生化方法包括一般蛋白质和同功酶等电泳法用于螺类分类是近十几年来的新发展(Davis 1967,Wright等1979、Rollinson等1979)。在螺类同功酶研究中,对酯酶同功酶的研究较多,据报道这个酶系不但可作种间分类参考,而且作为种下不同品系分类的借鉴,也可作为螺类遗传学研究的标志(Malek等1971、Bair等1973、Narang等1975、Jelnes 1979)。杰尔内斯(Jelnes 1979)指出,α-磷酸甘油脱氢酶对小泡螺(Bulinus)     

黑胸大蠊浓核病毒分类的相关研究

黑胸大蠊浓核病毒(pfDNV)是在我国首先发现并正式分类鉴定的蟑螂浓核病毒。该病毒属细小病毒科(Parvoviridae),浓核病毒亚科(Densovirinae)。但对该病毒的归属问题却一直没有确定,本文对此予以探讨。pfDNV的最新研究进展包括两个方面：全基因组核苷酸序列的测定,以及利用低温电镜技术和像重构方法对该病毒的三维重构(分辨率23A)。在此基础上,本文将pfDNV与其它病毒在基因组结构和三维结构方面进行了全面的对比分析,其结果并不支持目前对pfDNV的分类,因此建议对该病毒重新进行分类。     

细菌分类 原核生物的分类(综述)

分类、命名和鉴定分类,命名和鉴定是分类学中相互连系而又彼此独立的三个部份。分类(classification)是在相似性或相关性的基础上,把一个有机体放在一个分类阶元中。命名(nomenclature)是根据国际命名法规给有机体一个名称。鉴定(identification)是确定一个新分离的菌株可否归属于一个已建立命名的分类阶元的     

多元回归树与双向指示种分析在群落分类中的应用比较

采用两种群落分类方法——以环境梯度为分类依据的多元回归树(MRT)和多年来广泛应用的双向指示种分析(TWINSPAN), 对吕梁山南段森林群落进行了数量分类, 同时依据植物群落分类和命名原则, 对分类后的各群系进行命名, 并用吻合系数比较两种分类结果的吻合程度, 分析MRT的优劣势, 为以后选择合适的植物群落数量分类方法提供参考。结果表明: (1) MRT将41个森林样方分为4个群系, 分别为侧柏(Platycladus orientalis)群系、青榨槭(Acer davidii)群系、辽东栎(Quercus wutaishanica)群系、柿(Diospyros kaki)群系, 群系类型与TWINSPAN的分类结果相同; (2)根据群系的样方组成, 两种分类结果的吻合度较高, 吻合系数达80.5%; (3)与TWINSPAN相比, MRT同时以物种和环境信息为依据, 对有过渡性质的样方划分更为可靠。因此, 单纯从植被分类的角度来看, 尽管TWINSPAN的分类结果更客观, 但当TWINSPAN分类遇到困难时, 如在划分大样地连续样方或具有过渡性质样方时, MRT更有优势。     

三种恙虫生活史的研究

动物的分类以幼虫的特征作为主要根据的很少,但恙虫到现在还是以幼虫作为分类的对象。原因是:(1)恙虫的幼虫是动物的体外寄生虫,采集比较容易,而成虫和稚虫都是营自由生活的,采集比较困难;(2)恙虫的习性还不清楚,培养方法也不完善,所以尽管恙虫是某些疾病的重要传染媒介,引起了很多学者的研究,但就属于Trombiculidae     

DNA条形编码技术在动物分类中的研究进展

DNA条形编码(DNA Barcoding)技术是一种新的生物分类方法,它是分子生物学和生物信息学相结合的产物。这一概念认为,就像在商店里扫描仪读取条形码那样,对地球上每一种生物也能通过快速分析其DNA中的一小段(线粒体细胞色素C氧化酶Ⅰ亚基,mt COI)加以识别。在最近3年里,该技术已成为生物分类学中研究的热点。理论上,DNA条形编码在生物分类鉴定中具有重要作用,但目前国际上对其的争论也不少。综述了DNA条形编码技术的产生、发展概况、原理与操作及其在动物分类中的应用,突出了该技术在寄生虫分类中应用的意义与可行性,并讨论了DNA条形编码在生物分类应用中可能存在的问题。     

国产三角瓣花属(茜草科)订正

三角瓣花属Prismatomeris Thw．在Hooker(1873)和K．Schumann(1891)的茜草 科分类系统中隶于巴戟族Morindeae Miq．但在 Bremekamp(1966年)的分类系统中,其分类 位置未定。本属的胚根下位,花冠裂片镊合状排列和具针晶等特征与巴戟族相同,但它的花 离生,子房2室,胚珠盾形而着生于子房隔膜上半部等特征则与巴戟族明显不同。 因此, 将本属分立作族并置于Bremekamp所定界的茜草亚科Rubioideae中似乎较合适。 本文还提 供了经挑选的本属10对特征及其分类价值的说明。辨别了两个种：(1)将分布于中国的P. tetrandra(Roxb．)K．Schum. 修订为 “P.tetrandra (Roxb.) K. Schum. subsp. multiflora (Ridley,)Y．Z．Ruan”. (2)P. connata Y． Z. Ruan 被记述作新种它的热带新亚种是 P. connata Y． Z． Ruan subsp. hainanensis Y． Z． Ruan。     

生物演化与地质时间——从系统地质学时空观看地层学的发展

前言百余年来,虽然人们对栗蛤类(Nuculids,双壳纲)代表的构造特征及分类位置多有研究和报道,但正如L. R. Cox(1959)在“原鳃类的地质历史及栉齿类瓣鳃纲的双重起源”一文中所说:“Nuculacea超科和Nuculanacea超科的早期化石代表是相当难以区分的,如某些侏罗纪的Nuculana按分类位置属Nuculanacea超科,但未见均质结构。     

古栉齿类新亚科Veteranellinae subfam.nov.——兼论壳饰在古栉齿亚纲的分类意义

研究古栉齿亚纲(Palaeotaxodonta)的详细分类,是一个比较困难的课题,因为在这一亚纲,科以上分类单元之间,栉齿排布、韧带型式、外套湾特征及壳质微细构造类型等分类标志,尚较明显地有些差异,但在科以下的分类单元中,这些差异往往很不明显;有些作者强调的壳顶腔内脊和对肌痕的存在,     

On the origin of the Hirudinea and the demise of the Oligochaeta

The phylogenetic relationships of the Clitellata were investigated with a data set of published and new complete 18S rRNA gene sequences of 51 species representing 41 families. Sequences were aligned on the basis of a secondary structure model and analysed with maximum parsimony and maximum likelihood. In contrast to the latter method, parsimony did not recover the monophyly of Clitellata. However, a close scrutiny of the data suggested a spurious attraction between some polychaetes and clitellates. As a rule, molecular trees are closely aligned with morphology-based phylogenies. Acanthobdellida and Euhirudinea were reconciled in their traditional Hirudinea clade and were included in the Oligochaeta with the Branchiobdellida via the Lumbriculidae as a possible link between the two assemblages. While the 18S gene yielded a meaningful historical signal for determining relationships within clitellates, the exact position of Hirudinea and Branchiobdellida within oligochaetes remained unresolved. The lack of phylogenetic signal is interpreted as evidence for a rapid radiation of these taxa. The placement of Clitellata within the Polychaeta remained unresolved. The biological reality of polytomies within annelids is suggested and supports the hypothesis of an extremely ancient radiation of polychaetes and emergence of clitellates.     

On the ontogeny of the haptor and the evolution of the Monogenea

Data on the ontogeny of the posterior haptor of monogeneans were obtained from more than 150 publications and summarised. These data were plotted into diagrams showing evolutionary capacity levels based on the theory of a progressive evolution of marginal hooks, anchors and other attachment components of the posterior haptor in the Monogenea (Malmberg, 1986). 5 + 5 unhinged marginal hooks are assumed to be the most primitive monogenean haptoral condition. Thus the diagrams were founded on a 5 + 5 unhinged marginal hook evolutionary capacity level, and the evolutionary capacity levels of anchors and other haptoral attachement components were arranged according to haptoral ontogenetical sequences. In the final plotting diagram data on hosts, type of spermatozoa, oncomiracidial ciliation, sensilla pattern and protonephridial systems were also included. In this way a number of correlations were revealed. Thus, for example, the number of 5 + 5 marginal hooks correlates with the most primitive monogenean type of spermatozoon and with few sensillae, many ciliated cells and a simple protonephridial system in the oncomiracidium. On the basis of the reviewed data it is concluded that the ancient monogeneans with 5 + 5 unhinged marginal hooks were divided into two main lines, one retaining unhinged marginal hooks and the other evolving hinged marginal hooks. Both main lines have recent representatives at different marginal hook evolutionary capacity levels, i.e. monogeneans retaining a haptor with only marginal hooks. For the main line with hinged marginal hooks the name Articulon-choinea n. subclass is proposed. Members with 8 + 8 hinged marginal hooks only are here called Proanchorea n. superord. Monogeneans with unhinged marginal hooks only are here called Ananchorea n. superord. and three new families are erected for its recent members: Anonchohapteridae n. fam., Acolpentronidae n. fam. and Anacanthoridae n. fam. (with 7 + 7, 8 + 8 and 9 + 9 unhinged marginal hooks, respectively). Except for the families of Articulonchoinea (e.g. Acanthocotylidae, Gyrodactylidae, Tetraonchoididae) Bychowsky's (1957) division of the Monogenea into the Oligonchoinea and Polyonchoinea fits the proposed scheme, i.e. monogeneans with unhinged marginal hooks form one old group, the Oligonchoinea, which have 5 + 5 unhinged marginal hooks, and the other group form the Polyonchoinea, which (with the exception of the Hexabothriidae) has a greater number (7 + 7, 8 + 8 or 9 + 9) of unhinged marginal hooks. It is proposed that both these names, Oligonchoinea (sensu mihi) and Polyonchoinea (sensu mihi), will be retained on one side and Articulonchoinea placed on the other side, which reflects the early monogenean evolution. Except for the members of Ananchorea [Polyonchoinea], all members of the Oligonchoinea and Polyonchoinea have anchors, which imply that they are further evolved, i.e. have passed the 5 + 5 marginal hook evolutionary capacity level (Malmberg, 1986). There are two main types of anchors in the Monogenea: haptoral anchors, with anlages appearing in the haptor, and peduncular anchors, with anlages in the peduncle. There are two types of haptoral anchors: peripheral haptoral anchors, ontogenetically the oldest, and central haptoral anchors. Peduncular anchors, in turn, are ontogenetically younger than peripheral haptoral anchors. There may be two pairs of peduncular anchors: medial peduncular anchors, ontogentically the oldest, and lateral peduncular anchors. Only peduncular (not haptoral) anchors have anchor bars. Monogeneans with haptoral anchors are here called Mediohaptanchorea n. superord. and Laterohaptanchorea n. superord. or haptanchoreans. All oligonchoineans and the oldest polyonchoineans are haptanchoreans. Certain members of Calceostomatidae [Polyonchoinea] are the only monogeneans with both (peripheral) haptoral and peduncular anchors (one pair). These monogeneans are here called Mixanchorea n. superord. Polyonchoineans with peduncular anchors and unhinged marginal hooks are here called the Pedunculanchorea n. superord. The most primitive pedunculanchoreans have only one pair of peduncular anchors with an anchor bar, while the most advanced have both medial and lateral peduncular anchors; each pair having an anchor bar. Certain families of the Articulonchoinea, the Anchorea n. superord., also have peduncular anchors (parallel evolution): only one family, the Sundanonchidae n. fam., has both medial and lateral peduncular anchors, each anchor pair with an anchor bar. Evolutionary lines from different monogenean evolutionary capacity levels are discussed and a new system of classification for the Monogenea is proposed.In agreeing to publish this article, I recognise that its contents are controversial and contrary to generally accepted views on monogenean systematics and evolution. I have anticipated a reaction to the article by inviting senior workers in the field to comment upon it: their views will be reported in a future issue of this journal. EditorIn agreeing to publish this article, I recognise that its contents are controversial and contrary to generally accepted views on monogenean systematics and evolution. I have anticipated a reaction to the article by inviting senior workers in the field to comment upon it: their views will be reported in a future issue of this journal. Editor