Polyphyly across oceans: a molecular phylogeny of the Chromodorididae (Mollusca, Nudibranchia)

The Chromodorididae is a large and colourful family of nudibranch sea slugs distributed across the world's oceans. Most diversity is centred in the Indo-Pacific, but several genera are present in multiple ocean basins, or across regions separated by biogeographical barriers. The monophyly of these widespread genera had not been tested previously. We used 18S rDNA, 16S rDNA and COI sequence data to generate a molecular phylogeny for this group. We recovered evidence of paraphyly or polyphyly in all of the widespread genera examined ( Hypselodoris , Mexichromis , Chromodoris and Glossodoris ). East Atlantic Hypselodoris and west Atlantic + east Pacific Mexichromis species were more closely related to each other than they were to their Indo-Pacific congeners. The addition of Southern Ocean species of Digidentis demonstrated an interesting alternative to this relationship, becoming the sister group for the east Atlantic Hypselodoris on the basis of 16S and 18S data, but not COI data. Sister group relationships were recovered for most monotypic or enigmatic genera. Ardeadoris is linked to Glossodoris , as is Diversidoris ; Pectenodoris is sister to the Indo-Pacific Mexichromis clade, and Verconia is the sister to Noumea haliclona . Controversy surrounding the placement of the three most basal genera was only partially resolved. Using Actinocyclus to root the mitochondrial trees, Cadlinella was the unsupported sister to the Chromodorididae (excluding Cadlina ), and Tyrinna occupied a relatively basal position, although this also did not receive significant statistical support. Adding nuclear 18S data gave support for Cadlina as the sister group to the rest of the Chromodorididae s.s. Otherwise, like previous molecular studies, mitochondrial genes supported an alternative position for Cadlina (with other dorid genera).     

The Chromodorididae (Opisthobranchia: Mollusca) of the Indo-West Pacific: further species of Glossodoris, Thorunna and the Chromodoris aureomarginata colour group

Nineteen species of chromodorid nudibranchs from the Indo-West Pacific are described including 12 new to science. There are four new species of Glossodoris and one new species of Thorunna . The anatomy of two other species of Thorunna, T. daniellae and T. florens , is described and the problematical 'Hypselodoris' kulonba Burn, 1966 is shown to belong to the genus Digidentis. New species of chromodorids which are white with a yellow or red margin. or markings. from the genera Durvilledoris. Noumea and Cadlina are also described. Notes on colour variation in Glossodoris pallida and Chromodoris splendida are included.     

Molecular phylogeny of Glossodoris (Ehrenberg, 1831) nudibranchs and related genera reveals cryptic and pseudocryptic species complexes

Chromodorid nudibranchs (Chromodorididae) are brightly coloured sea slugs that live in some of the most biodiverse and threatened coral reefs on the planet. However, the evolutionary relationships within this family have not been well understood, especially in the genus Glossodoris. Members of Glossodoris have experienced large‐scale taxonomic instability over the last century and have been the subject of repeated taxonomic changes, in part due to morphological characters being the sole traditional taxonomic sources of data. Changing concepts of traditional generic boundaries based on morphology also have contributed to this instability. Despite recent advances in molecular systematics, many aspects of chromodorid taxonomy remain poorly understood, particularly at the traditional species and generic levels. In this study, 77 individuals comprising 32 previously defined species were used to build the most robust phylogenetic tree of Glossodoris and related genera using mitochondrial genes cytochrome c oxidase subunit I and 16S, and the nuclear gene 28S. Bayesian inference, maximum likelihood, and maximum parsimony analyses verify the most recent hypothesized evolutionary relationships within Glossodoris. Additionally, a pseudocryptic and cryptic species complex within Glossodoris cincta and a pseudocryptic complex within Glossodoris pallida emerged, and three new species of Doriprismatica are identified.     

Traditional taxonomic groupings mask evolutionary history: a molecular phylogeny and new classification of the chromodorid nudibranchs

Chromodorid nudibranchs (16 genera, 300+ species) are beautiful, brightly colored sea slugs found primarily in tropical coral reef habitats and subtropical coastal waters. The chromodorids are the most speciose family of opisthobranchs and one of the most diverse heterobranch clades. Chromodorids have the potential to be a model group with which to study diversification, color pattern evolution, are important source organisms in natural products chemistry and represent a stunning and widely compelling example of marine biodiversity. Here, we present the most complete molecular phylogeny of the chromodorid nudibranchs to date, with a broad sample of 244 specimens (142 new), representing 157 (106 new) chromodorid species, four actinocylcid species and four additional dorid species utilizing two mitochondrial markers (16s and COI). We confirmed the monophyly of the Chromodorididae and its sister group relationship with the Actinocyclidae. We were also able to, for the first time, test generic monophyly by including more than one member of all 14 of the non-monotypic chromodorid genera. Every one of these 14 traditional chromodorid genera are either non-monophyletic, or render another genus paraphyletic. Additionally, both the monotypic genera Verconia and Diversidoris are nested within clades. Based on data shown here, there are three individual species and five clades limited to the eastern Pacific and Atlantic Oceans (or just one of these ocean regions), while the majority of chromodorid clades and species are strictly Indo-Pacific in distribution. We present a new classification of the chromodorid nudibranchs. We use molecular data to untangle evolutionary relationships and retain a historical connection to traditional systematics by using generic names attached to type species as clade names.     

The Chromodorididae (Opisthobranchia: Mollusca) of the Indo-West Pacific: Chromodoris aureomarginata, C. verrieri and C. fide lis colour groups

Nineteen species of chromodorid nudibranchs are described including three new species of Chromodoris , two of Glossodoris and one each of Noumea, Cadlina and Thorunna from the Indo-West Pacific. The colour of all species is white with either a single yellow or gold band at the edge of the mantle or a double band of red and yellow, or orange and red or purple. All previously described species with similar colour patterns, from both the Indo-West Pacific and other regions are discussed.     

The Chromodorididae (Opisthobranchia: Mollusca) of the Indo-West Pacific: the genus Glossodoris Ehrenbergh (= Casella, H. & A. Adams)

The genus Glossodoris Ehrenberg is reviewed and 28 species are placed in the genus. Seventeen species are fully described and of these, seven are named as new species. Four others are considered new to science, but insufficient material is available to name them. Published information on a further 11 species is included as is a discussion on phylogenetic trends within the genus.     

Opisthobranchiate Mollusca from Ghana: Chromodorididae

Nine species of the opisthobranch family Chromodorididae are described from Ghana: Cadlina evelinae Marcus; C. rumia Marcus; C. dubia sp. nov.; Chromodoris ghanensis (Edmunds); C. kpone sp. nov.; C. luleorosea (Rapp); Hypselodoris tana sp. nov.; H. bilineata (Pruvot-Fol) and Mexichromis tricolor (Cantraine). The small number of species found belonging to this warm-water family is attributed to the cold water of the Benguela current.     

Sperm ultrastructure in the nudibranch genus Halgerda with reference to other Discodorididae and to Chromodorididae (Mollusca: Opisthobranchia)

Comparative sperm ultrastructure within the molluscan nudibranch genus Halgerda (Discodorididae) was examined for the first time using transmission electron microscopy (TEM), based on 17 of the 35 known species. In addition, observations on two other discodorids are made to facilitate outgroup comparison with Halgerda, including one species of Discodoris (D. boholiensis) and Asteronotus cespitosus (currently accepted as the closest sister taxon to Halgerda). Comparison was also made with some genera of the Chromodorididae in view of sperm similarities. Spermatozoa of all species examined were of the complex, helical, elongate ( approximately 300-400 micro m) type characteristic of most heterobranch gastropods. These cells exhibit the following discrete regions (in anteroposterior sequence) : an acrosomal complex (composed of a rounded, membrane-bound vesicle and a column-like pedestal); a solid, helical nucleus; an elongate, helical midpiece (composed of an axoneme and associated nine coarse fibers, an enveloping mitochondrial derivative of matrix, and paracrystalline materials and glycogen helix); an annular complex; and a short glycogen piece. Of these regions, the midpiece is by far the longest, occupying over 90% of the total sperm length. Comparison with other members of the radula-bearing cryptobranch dorids reveals several sperm similarities to other genera in the clade, particularly those of other Discodorididae and also with the Chromodorididae. Comparison with previously studied genera reveals noteworthy sperm differences within the Discodorididae. The most notable differences are the internal structure of the acrosomal pedestal (long and homogeneous in Halgerda, Discodoris; short and homogeneous in Asteronotus; long and finely striated in Rostanga; oblong with angular electron-lucent striations in Jorunna) and the internal structure of the glycogen piece. The pronounced helical keels of most Halgerda and Discodoris nuclei contrast with the weakly helical nucleus of Asteronotus. Sperm features alone do not provide a means of defining the genus Halgerda or the family Discodorididae nor do they support the monophyletic status of the caryophyllidia-bearing dorids. Important sperm characters such as the acrosome, nucleus, and midpiece can often still be determined from specimens that have been initially fixed in formalin, then stored in ethanol for extended periods of time (i.e., museum material). Of all sperm features, the mitochondrial derivative of the midpiece is the most resistant to long-term fixation : the survival of acrosomal, nuclear, and axonemal components is variable, presumably a factor of prefixation autolysis, varied primary fixation times and temperatures, formalin quality, and duration of alcohol storage.     

The Chromodorididae (Opisthobranchia: Mollusca) of the Indo-West Pacific: the genus Ceratosoma J. E. Gray

The genus Ceratosoma (Nudibranchia: Chromodorididae) is reviewed and seven species, including two new species, are recognized. Species of the genus are known only from the Indo-West Pacific and it is suggested that the external body shape is the most useful character in distinguishing species.     

On the affinities ofZuluscaphites van Hoepen 1955 (Cretaceous Ammonoidea) from the Albian of Zululand,South Africa

Zuluscaphites van Hoepen 1955, an enigmatic ammonite originally described from the Middle or Upper Albian of Zululand, South Africa, is shown to be a member of the acanthoceratacean family Lyelliceratidae, subfamily Stoliczkaiinae; it is not a heteromorph as originally proposed. Huescarites Latil 1991 is a junior synonym of Zuluscaphites as are the type species of the two genera, Z. orycteropusi and H. companyi.     

A light and electron microscopic study of Scherffelia dubia, a new member of the scaly green flagellates (Prasinophyceae)

In clonal culture Scherffelia dubia (Perty) Pascher shows a considerable range of morphological variation, with different cell shapes being produced including those typical for three other species of Scherffelia Pascher ( S. opisthostigma Skuja, S. ovata Pascher, S. pelagica Skuja) and one species of Tetraselmis Stein ( T. bichlora Ettl & Ettl). It is concluded these taxa should be reduced to the synonymy of S. dubia , the type species of Scherffelia. The general cell morphology of S. dubia is described in detail, including a serial section and absolute configuration analysis of the flagellar apparatus. S. dubia is compared with species of Tetraselmis of which ultrastructural details are known and it is shown that both genera are very similar but the generic distinction is nevertheless justified. Main features of distinction include the pyrenoid (present in Tetraselmis but lacking in Scherffelia ) and the chloroplast (single and more or less cup-shaped in Tetraselmis , two separate lateral chloroplasts in Scherffelia ). Both genera are accommodated in the same family, the correct name being Chlorodendraceae and not Tetraselmidaceae or Platymonadaceae which have often been used.     

Breaking family ties: taxon sampling and molecular phylogeny of chromodorid nudibranchs (Mollusca,Gastropoda)

Johnson, R. F. (2010). Breaking family ties: taxon sampling and molecular phylogeny of chromodorid nudibranchs (Mollusca, Gastropoda). —Zoologica Scripta, 40, 137–157. Although researchers have debated the monophyly of the diverse chromodorid nudibranchs (Chromodorididae) for over 100 years, the monophyly of this family has not been properly tested. Recent morphological and molecular phylogenetic studies have added to the debate, but have not used appropriate methods to resolve this issue. I investigate how outgroup choice and taxon sampling influences tree topology and in turn the recovery of chromodorid monophyly. As a demonstration of these potential methodological problems, I then present phylogenies resulting from different taxon‐sampling schemes using the same molecular data. Taxon sampling has a strong influence on the resulting phylogenies. With comprehensive taxon sampling and outgroup selection, Cadlina is not a member of the Chromodorididae. The chromodorid nudibranchs without Cadlina are monophyletic and possibly sister to the Actinocyclidae. Additionally, I found, for the first time, support for most current family groupings in the Doridoidea. I propose a new classification in which Cadlina is not considered a member of the Chromodorididae. Instead, I resurrect the family name Cadlinidae to include the genera Cadlina and Aldisa.     

Petraliellidae Harmer, 1957 (Bryozoa: Cheilostomata) from Queensland,Australia

Several species of the family Petraliellidae were first described from the coast of Queensland, including the type species of Sinupetraliella, S. litoralis. These species are redescribed from type, or topotype specimens, and include Petraliella concinna, which has not been certainly found since its introduction in 1891; lectotype material is designated for P. buski and P. magna. Six other species are described from Queensland, P. crassocirca, P. dentilabris, P. dorsiporosa, Mucropetraliella bennetti, M. serrata and M. tuberosa. The species Mucropetraliella tuberosa is a new addition to the Queensland fauna and is described and illustrated here for the first time since its introduction in 1884. The characters of the family Petraliellidae are briefly discussed and the genera to which the Queensland species are assigned is reviewed. A taxonomic key to the ten Queensland petraliellid species described is also provided.     

Alonella and Dunhevedia (Chydoridae,Cladocera): Morphology of trunk limbs

Summary The legs of some species of genera Alonella and Dunhevedia are described, including the type species of these genera. The structure of the endites and gnathobases is depicted and described in detail. The structure of legs of the studied species is compared with that of species of some other genera, including Eurycercus and Saycia.     

Deep-sea asellote isopods of the north-east Atlantic: the family Dendrotionidae and some new ectoparasitic copepods

A new species of Dendromunna and two new species of Dendrotion are described from abundant material collected in the Rockall Trough region of the north-east Atlantic. The taxonomy of the little known benthic deep-sea asellote isopod family Dendrotionidae is reviewed and keys provided for genera and species. Also diagnosed and described are two new species belonging to a new genus of siphonostomatoid copepod found as ectoparasites on the walking legs of the new Dendromunna. The new parasites belong in the Rhizorhina group of genera within the family Nicothoidae.     

北京山区野生维管束植物区系

在北京山区共有高等植物1166种(含变种、变型),隶属于122科、503属;其中蕨类植物17科、26属、62种(变种),裸子植物3科、7属、7种;双子叶植物88科、371属、863种(变种);单子叶植物14科、99属、234种(变种)。优势科属的统计表明,本区维管束植物一方面集中于菊科、蔷薇科等一些世界性大科之中,同时又向少种科、单种科分散。在北京山区共调查到1个单种科,6个单属科。本区分布的单种属和寡种属共72个,其中单种属有31个。种子植物属的分布区类型占有全国植物科的15个分布区类型,以温带成分的属为主,其占种子植物总属数的55.34%;其次是泛热带分布类型,共计60属,占总属12.6%,中国特有分布的属有11属,占总属数的2.31%,所占比例较小。     

浙江省台州市种子植物区系分析

台州市种子植物丰富,据统计有野生种子植物150科、784属、1892种(含种下分类群),其中裸子植物6科、12属、16种,被子植物144科、772属、1876种。优势科明显,其中10种以上的科有45个,含526属、1453种,分别占总属数、总种数的67.09%、76.80%。本区系历史悠久,起源古老,小属和极小属共707个,占总属数的90.18%。科的分布区类型以热带、亚热带分布最多,其次是世界分布,第3是温带分布。属的分布区类型可划分为14类,以温带性成分为主,也兼有相当比例的热带性成分,具有亚热带特性。地理成分复杂,与世界各地联系广泛。该地区有中国特有属14属,列为国家首批保护的珍稀植物20种。