Diversity of the structure of lateral line scales in Pleuronectiformes

Scales of the lateral line (Sll) in representatives of the order Pleuronectiformes were studied, and its large morphological diversity was revealed. It was shown that Sll early in ontogenesis reach a definitive structure and have an insignificant individual variation. In some cases, features of Sll are species specific, but the main distinctions in its structure are typical of taxa of the supraspecies rank. Types of structure of Sll, as well as tendencies in its specialization, are distinguished.     

Specific features of the seismosensory system and their use in the systematics of five families of the order pleuronectiformes

The structure of the seismosensory system (SSS) was studied in 23 species of 13 genera from the families Rhombosoleidae, Poecilopsettidae, and Samaridae, and a comparison and generalization of the obtained data with those published previously for the families Psettodidae and Pleuronectidae was performed. It was shown that the individual variability of SSS does not concern topography of canals, being manifested in the variation of the number of pores in particular canals. Interspecific differences also concern mainly the number of pores, and revealing these differences requires, as a rule, statistic methods. Considerable differences were found between genera, so that each of the 40 studied genera can be characterized by a unique combination of SSS characters whose polarization was established on the basis of a reduction trend of SSS transformations common for bony fish. The maximum number of plesiomorphies of SSS was found in the genus Psettodes (Psettodidae). In the framework of the family Pleuronectidae, the most generalized structure of SSS was found in representatives of the subfamily Hippoglossinae, and the most advanced, in Pleuronectinae. In the family Rhombosoleidae, the most generalized structure of SSS is in the genus Oncopterus, the remaining representatives of the family Rhombosoleidae are characterized by a different degree of its reduction. In rather closely related families Poecilopsettidae and Samaridae, SSS is considerably reduced, which may be connected with the miniatuarization of their representatives. A small number of considered characters and a high level of homoplasia hinders their use in cladistic study; however, considerable differences between the studied genera and a low interspecific variation permits for the considering of specific features of SSS as valuable diagnostic characters of genera, and the degree of reduction of this system can indicate the relative degree of advancement of a specific taxon of Pleuronectiformes.     

Faunistic similarity and endemism of earthworms in east mediterranean region

The analysis presents earthworm distribution in eight designated tectonic units (C—Cyprus, EP—East Pondites, ET—East Taurus block, Sc—Sakarya continent, Kb—Kırşehir block, L—the Levant, TM—Taurus–Menderes block, WP—West Pondites) in the East Mediterranean region (EM). It represents a full list of earthworm species (N = 81) of the region and reveals significant faunal similarities between Sc + WP, and between Kb + TM. The new Sc + WP unit is characterized by the presence of archaic (Spermophorodrilus) as well as modern earthworm fauna. In contrast, the second newly established Kb + TM unit is characterized by poorly presented earthworm autochthonous fauna and by a lack of endemic species. The analysis done on the species list (N = 73) representing the autochthonous family Lumbricidae showed statistically supported separation of L and EP between themselves and from other designated units. The Levant, part of the Arabian tectonic plate, is characterized by a high level of endemism in ancient (Healyella) and modern (Dendrobaena, Perelia) genera, and by the lack of archaic genera. The EP harbors unique species representing archaic (Eophila), ancient (Healyella), and modern (Allolobophora, Aporrectodea, Dendrobaena and Eisenia) earthworm genera in the EM. The analysis also indicates origin of earthworm fauna in TM and faunistic relationships among the designated units. Clearly, the present-day division of the EM earthworm fauna shows recognizable influences of tectonic history.     

Taxonomic classification of the reef coral families Merulinidae,Montastraeidae, and Diploastraeidae (Cnidaria: Anthozoa: Scleractinia)

Modern coral taxonomy has begun to resolve many long‐standing problems in traditional systematics stemming from its reliance on skeletal macromorphology. By integrating examinations of colony, corallite, and subcorallite morphology with the molecular sequence data that have proliferated in the last decade, many taxa spread across the scleractinian tree of life have been incorporated into a rigorous classification underpinned by greater phylogenetic understanding. This monograph focuses on one of the most challenging clades recovered to date – its disarray epitomized by the informal name ‘Bigmessidae’. This group of predominantly Indo‐Pacific species previously comprised families Merulinidae, Faviidae, Pectiniidae, and Trachyphylliidae, but in a recent study these have been incorporated within Merulinidae. We studied 84 living merulinid species by examining morphological traits at three different scales of coral skeletal structure ? macromorphology, micromorphology, and microstructure ? to construct a morphological matrix comprising 44 characters. Data were analysed via maximum parsimony and also transformed onto a robust molecular phylogeny under the parsimony and maximum likelihood criteria. Comparisons amongst morphological character types suggest that although many characters at every scale are homoplastic, some to a greater extent than others, several can aid in distinguishing genus‐level clades. Our resulting trees and character analyses form the basis of a revised classification that spans a total of 139 species contained within 24 genera. The tree topologies necessitate the synonymization of Barabattoia as Dipsastraea, and Phymastrea as Favites. Furthermore, Astrea and Coelastrea are resurrected, and one new genus, P aramontastraea Huang & Budd gen. nov. , is described. All the genera in Merulinidae, along with the monotypic Montastraeidae and Diploastraeidae, are diagnosed based on the characters examined. The integrative classification system proposed here will form the framework for more accurate biodiversity estimates and guide the taxonomic placement of extinct species. © 2014 The Linnean Society of London     

Multigene phylogeny of Synura (Synurophyceae) and descriptions of four new species based on morphological and DNA evidence

We used phylogenetic analyses based on multiple gene sequences (partial nr SSU and LSU rDNA, partial pt LSU rDNA, psaA and rbcL) from 148 strains (including three outgroups) and scale ultrastructure to examine phylogenetic relationships among species of the colonial genera Synura and Tessellaria. The phylogenetic tree based on the combined dataset was congruent with ultrastructural characteristics of the scales. Synura was divided into three major clades, two including species in section Synura, and one representing section Peterseniae. One clade, consisting of seven strains of S. uvella (section Synura), diverged at the base of the genus. The second clade consisted of the remaining species belonging to the section Synura. The third clade, containing organisms in the section Peterseniae and characterized by scales possessing a keel, was monophyletic with strong support values. Based on our findings, S. uvella needs to be in a separate section from other spine-bearing species, and we therefore propose new sectional ranks; Synura, Peterseniae, Curtispinae (presence of body scales with slender spines, tubular scales and caudal scales). We further propose four new species based on phylogenetic analyses and unique scale characters: S. longitubularis sp. nov., S. sungminbooi sp. nov., S. soroconopea sp. nov. and S. lanceolata sp. nov. Lastly, we propose a new genus name, Neotessella, to replace the invalid use of the name Tessellaria.     

Ultrastructural and phylogenetic assessment of wax glands in pit scales (Homoptera : Coccoidea)

TEM/SEM and computerized images of 5 wax glands for 3 type species of Coccoidea (Homoptera): Asterodiaspis variolosa (Asterolecaniidae), Cerococcus quercus (Cerococcidae) and Lecanodiaspis sardoa (Lecanodiaspididae) were studied. Their cuticular structures were compared with 142, 56, and 61 species in their respective families to determine relationships among pit scale taxa. Significant differences include: the morphology of the outer and inner ductule of the tubular duct gland, structure of the pores (8-shaped, multilocular and quinquelocular), and the absence or presence of cribriform plates and their structural variations. Three distinctive tubular duct shapes (asterform, ceroform and lecanoform) are common in pit scale species. Apomorphic characteristics of the asterform tubular ducts include an absence of the inner ductule and the progressive reduction of the outer ductule's diameter from the pore to its inner end. These characters easily separate asterolecaniids from the cerococcid-lecanodiaspidid lineage. The constricted lecanoform tubular ducts and the curved teeth on the rim at the inner end of the outer ductule in the ceroform tubular ducts are regarded as autapomorphic. The presence of 8-shaped pores is considered a plesiomorphic condition. Specific cuticular variations of the 8-shaped pores, characterizing familial taxa, include pores even with the surface in asterolecaniids, pores with raised walls in cerococcids, and bent pores in lecanodiaspidids. The dominant 8-shaped pore patterns in pit scales are those arranged in a marginal band in lecanodiaspidids, in a swirl-like pore pattern in the cerococcids, and in a marginal row in asterolecaniids. A divergent evolutionary trend is noted for the structure of the cribriform plate; they are with micro-orifices in cerococcids, but without micro-orifices in lecanodiaspidids. The former state is considered apomorphic. Cribriform plates arranged in clusters characterize the cerococcids, while plates in longitudinal rows characterize the lecanodiaspidids. These data confirm the concept that the pit scales constitute a paraphyletic group and the Asterolecaniidae, Cerococcidae and Lecanodiaspididae are monophyletic.     

Pollen morphology and its taxonomic significance of the monotropoideae (Ericaceae)

A palynological survey, including LM, SEM and TEM is presented for eight genera, nine species and 76 samples of the Monotropoideae which is composed of 10 genera and 13 species. On the basis of the aperture number and shape, the following six pollen types are recognized: 1) 3-colp(oroid) ate—Allotropa, 2) 2-colpor(oid)ate—Monotropsis andHemitomes, 3) 4-colpor(oid)ate—Pterospora, Sarcodes andPleuricospora, 4) 2- and 3-colpor(oid)ate—Monotropa hypopitys, 5) 3-colporate and-porate —Monotropa uniflora, 6) 3- to 4- porate—Monotropastrum humile. Relationships among taxa within the Monotropoideae are illustrated on the palynological characters including the aperture type, exine sculpture and structure. Both pollen grains with two and four apertures have evolved independently from pollen grains with three apertures, according to the infraspecific variation of aperture numbers and the usual occurrence of three-aperturate pollen grains in the Ericaceae. 3-colp(oroid)ate pollen ofAllotropa is the most primitive and occupies an isolated position in the subfamily, on the other hand 3- to 4-porate pollen ofMonotropastrum humile is most advanced in the subfamily, probably even in the Ericaceae. A reduced sexine inMonotropastrum humile appears to be a specialized pollen character. Infraspecific geographical difference in palynological characters is revealed in two species ofMonotropa for the first time.M. hypopitys is basically characterized by pollen grains with two apertures in the New World vs. three apertures in the Old World.M. uniflora is basically characterized by 3-porate pollen in the New World vs. 3-colporate in the Old World. In both species pollen grains with more primitive characters usually occur in the Old World.     

Phylogenetic classification of the Drosophilidae Rondani (Diptera): the role of morphology in the postgenomic era

Molecular sequences now overwhelm morphology in phylogenetic inference. Nonetheless, most molecular studies are conducted on a limited number of taxa, as DNA rarely can be analysed from old museum types or fossils. During the last 20 years, more than 150 molecular studies have challenged the current phylogenetic classification of the family Drosophilidae Rondani based on morphological characters. Most studies concerned a single genus, Drosophila Fallén, and included only few representative species from 17 out of the 78 genera of the family. Therefore, these molecular studies were unable to provide an alternative classification scheme. A supermatrix analysis of seven nuclear and one mitochondrial genes (8248 bp) for 33 genera was conducted using outgroups from one calyptrate and four ephydroid families. The Bayesian phylogeny was consistent with previous molecular studies including whole genome sequences and divided the Drosophilidae into four monophyletic clades. Morphological characters, mostly male genitalia, then were compared thoroughly between the four clades and homologous character states were identified. These states were then checked for 70 genera and a revised phylogenetic, family‐group classification for the Drosophilidae is proposed. Two genera –Cladochaeta Coquillett and Diathoneura Duda – of the tribe Cladochaetini Grimaldi are transferred to the family Ephydridae. The Drosophilidae is divided into two subfamilies: Steganinae Hendel (30 genera) and Drosophilinae Rondani (43 genera). A further two genera, Apacrochaeta Duda and Sphyrnoceps de Meijere, are incertae sedis, and Palmophila Grimaldi, is synonymized with Drosophila syn.n. The Drosophilinae is subdivided into two tribes: the re‐elevated Colocasiomyini Okada (nine genera) and Drosophilini Okada. The paraphyly of the genus Drosophila was not resolved to avoid affecting the binomina of important laboratory model species; however, its subgeneric classification was revised in light of molecular and morphological data. Three subgenera, namely Chusqueophila Brncic, Phloridosa Sturtevant and Psilodorha Okada, were synonymized with the subgenus Drosophila (Drosophila) Fallén syns.n. Among the 45 species groups and 5 species complexes of Drosophila (Drosophila), 22 groups and 1 complex were transferred to the subgenus Drosophila (Siphlodora) Patterson & Mainland and 6 groups, 2 species subgroups and 3 complexes are considered incertae sedis within the genus Drosophila. Different morphological characters provide different signals at different phylogenetic scales: thoracic characters (wing venation and presternal shape) discriminate families; grasping and erection‐related characters discriminate subfamilies to tribes; whereas phallic paraphyses, i.e. auxiliary intromittent organs, discriminate genera and Drosophila subgenera. The study shows the necessity of analysing morphological characters within a molecular phylogenetic framework to translate molecular phylogenies into taxonomically‐comprehensive classifications.     

Imaging scale surface topography of an endemic cyprinid fish,Garra sharq from the Arabian Peninsula: An integrated optical light and scanning electron microscopy approach

The optical light microscopy and scanning electron microscopy techniques have proven to play a key and noteworthy role in the advancement of morphological studies in general, and in investigating fish scale morphology in particular. These techniques have illustrated several hidden architectural structures in scales that contribute effectively to fish identification and classification. The scale morphological and topological characters such as type, size, shape, lateral surface, focus position, circuli appearance, radii type, lepidonts, and posterior and anterior margin shapes were obtained using macro- and microscopic analysis in six body regions for three size classes of Garra sharq, a cyprinid endemic fish of the Arabian Peninsula. The general scale type in the studied G. sharq species was a basal elasmoid cycloid and a sectioned type. As a protective structure, the scales display several specific characteristics including firm attachment to the fish body, overlapping, and thin structure with a high surface area and high strength. These characteristics improve scale resistance to penetration, increase protection against mechanical injury and microbial infection, enhance scale flexibility, reduce fish weight (reduce friction drag), and increase scale transparency. The scales demonstrate plasticity in focus shape, size, and position in the six fish body parts and fish size groups. The examined scales displayed narrow or wide grooves (radii) in three types including primary, secondary, and tertiary present in all four scale fields (anterior, posterior, and laterals), thus a tetra-sectioned type that is almost specific to the genus Garra. This characteristic also increases scale flexibility. The rostral margin of scales was characterized by the presence of waved and striate types. The lepidont shape and size varied being blunt, flat, pointed, tiny, sharp, short, and long. Some of these scale characters and their morphologies could be used as an alternative tool for identification, classification, and phylogenetic interpretation among the different freshwater fish species and genera.     

瑞香属和荛花属的数量分类研究

瑞香属和荛花属为瑞香科瑞香亚科的落叶或常绿灌木,中国西南部是瑞香属和荛花属的重要分化中心。全世界共有瑞香属95种、荛花属70种,中国分布有瑞香属52种、荛花属49种。瑞香属和荛花属的分类学研究一直存在不同程度的分歧。花盘形状和果实类型在传统分类中一直是区分瑞香属和荛花属的典型特征,而花盘形态和果实类型在2个属中存在交叉和过渡,部分植物分类学家根据这些特征将两个属进行过不同程度的归并。该研究采用数量分类法对瑞香属77种(变种)和荛花属62种(变种)植物,选取32个形态学性状进行聚类分析和主成分分析。结果表明:聚类分析和主成分分析均显示两属均未形成单系类群。在主成分分析中,前3个主成分分析的贡献值为35.56%,传统分类中用来区分两属的花盘形状、叶序及果实类型等特征对前3个主成分贡献相对较小,因此,传统分类学中对这两个属进行区分的性状并没有典型的分类学意义。同时,聚类图和主成分分析得到的散点图均不能将这两个属区分开来。数量分类研究结果显示两属植物存在明显的交叉,支持瑞香属和荛花属不是两个独立自然类群的观点。     

Comparative Analysis of a Mitochondrial DNA Control Region Fragment Amplified from Three Adriatic Flatfish Species and Molecular Phylogenesis of Pleuronectiformes

The 5′-end of the mitochondrial control region of three Pleuronectiformes from the Adriatic Sea, Platichthys flesus italicus (Adriatic flounder), Solea vulgaris (common sole), and Solea kleini (Klein's sole), was sequenced and compared with that of six other flatfish species from the families Pleuronectidae and Bothidae. The sequence structures of all flatfishes appear very similar and consist of alternate short segments with low, medium, and high rates of nucleotide substitution. Four conserved 19-bp repeats occur at the beginning of the European and Adriatic flounder sequences. The common occurrence of tandem arrays in fish control regions could be related to a stable secondary structure. Molecular phylogenetic relationships among Pleuronectiformes agree well with previous morphologic data at all taxonomic levels. Molecular analyses could therefore contribute to resolving phylogenetic and taxonomic debates within the Pleuronectiformes. Received December 1, 1997; accepted June 30, 1998.     

The use of hair morphology in the classification of galagos (Primates, subfamily galagoninae)

The outer epidermal hair structure of bushbabies or galagos varies considerably between genera and species. Comparative morphology can therefore be useful in taxonomic studies, particularly when assessing the true status of newly nominated or misclassified species. Quantitative measurements of outer epidermal hair scales (scale frequency and scale complexity) were made for populations representing 13 taxa within the subfamily Galagoninae. Intraspecific variations in both measures of hair morphology were relatively minor. By contrast, significant interspecific differences were observed, even between closely related, well-established species (e.g. in the greater galagosOtolemur crassicaudatus andO. garnettii and lesser galagosGalago senegalensis andGalago moholi). Assessment of scale frequency resulted in the recognition of all species of the greater and needle-clawed galago genera and added support for nomination to species status of two former subspecies (O. argentatus andE. pallidus). Similar divisions were made in the lesser and dwarf galagos with respect to scale complexity. Possible explanations for the differences in outer epidermal hair scales are discussed. Characteristics of outer epidermal hair scales provide a useful guide to species identity in the subfamily Galagoninae, and the same may prove to be true for other groups of nocturnal mammals.     

Habitat associations with topography and canopy structure of tree species in a tropical montane forest on Mount Kinabalu,Borneo

Habitat associations with topography and canopy structure of 42 abundant tree species were studied in a 2.74-ha plot of tropical montane forest on Mount Kinabalu, Borneo. Many of these species belong to the same higher taxa including eight families and four genera. Analysis of intraspecific spatial distributions for stems ≥ 10 cm diameter revealed that 28 species (including all six species of Fagaceae) showed aggregated distributions at the 100-m² and/or 400-m² scales, and that 20 species showed habitat associations with topography by torus-translation tests; 17 species showed both characteristics. Species' associations with the local canopy structure were characterized by crown position index (CPI), which was defined relative to neighbour trees. The CPI differed greatly among individual stems at 10–40 cm diameter, and 19 species showed significantly different frequencies of crowns exposed vertically versus those shaded beneath the canopy. Mean growth rates at 10–40 cm diameter and size distributions of species were not related to topographic associations, but were explained by the associations with canopy structure; species with more exposed crowns grew faster and had less positively skewed distributions. Diversity in habitat associations was manifest between two genera (Syzygium and Tristaniopsis) in the family Myrtaceae and among species in these genera, but was less evident in other families and two genera (Garcinia and Lithocarpus). This revised version was published online in June 2006 with corrections to the Cover Date.     

Macroecology of Aquatic Insects: A Quantitative Analysis of Taxonomic Richness and Composition in the Andes Mountains of Northern Ecuador

To determine the spatial dynamics of Neotropical lotic insect species, specimens were collected from 41 streams on the eastern and western flanks of the Andes Mountains in Ecuador. We examined the manner in which taxonomic richness and composition differed with elevation, latitude, and versant. Statistical analyses were limited to 5 families (Ephemeroptera: Baetidae, Leptohyphidae, Oligoneuriidae; Heteroptera: Naucoridae; Coleoptera: Elmidae), comprising 32 genera and 85 species, for which identifications or morphospecies assignments were reliable. Assessment of taxonomic diversity was based on the richness of genera and species at each site. In addition, each site was characterized by species richness within each of 4 families with more than 10 species. The effects of versant and transect on composition and structure were family‐specific. Mean site differences between versants in elmid richness at generic and specific levels depended on transect. Only baetid richness was affected by versant and transect in a consistent manner. Variation among sites in composition based on all genera and species was captured using multidimensional scaling (MDS). Subsequent MANOVAs based on scores from MDS axes revealed that differences between versants were much stronger in the southern transect, although transects differed from each other at specific and generic levels. A Jaccard's similarity matrix was computed for each family to reflect the spatial organization of taxonomic composition. Mesogeographic patterns of species composition for each of the four families were correlated (Mantel analysis) at both the regional level and at the level of the entire study area. At the regional level, the only pair of families to exhibit correlated patterns of species composition was elmids and naucorids in the southwestern region. The pattern of species composition for each family was correlated with the patterns for one or more other families at the level of the entire study area. Thus, spatial dynamics of species composition was similar for the families examined, suggesting that the Andes exert a consistent influence on species distributions within families, regardless of ordinal affiliation. At a local scale, however, the way in which taxonomic composition changed with latitude and versant was family‐specific. Mayflies, the most vagile of the taxa studied, had the highest percentage of species overlap between versants. Of three genera of Naucoridae collected, species of Ambrysus, of probable Mexican origin, were found only on the eastern versant, corroborating other evidence that the genus is recent in South America. Moreover, dispersion by Ambrysus across the Andes Mountains may not have occurred, as it has for Cryphocricos and Limnocoris, which are of probable South American origin.     

Phylogenetic and taxonomic analysis of flatfish species (Teleostei,Pleuronectiformes) inferred from the primary nucleotide sequence of cytochrome oxidase 1 gene (<Emphasis Type="Italic">Co-1</Emphasis>)

Seventeen nucleotide sequences of Co-1 gene from 13 Pleuronectiformes species and 2 Perciformes species served as the outgroup were examined. For divergence comparison, the initial stage involved calculation of pairwise p-distances for all investigated sequences. This allowed to evaluate the nucleotide diversity on four phylogenetically different levels: (1) intraspecific, (2) intrageneric, (3) intrafamilial, and (4) intraordinal. The values of p-distances for the Co-1 gene for the four mentioned categories were (1) 0.93 ± 0.73%, (2) 11.72 ± 1.86%, (3) 12.10 ± 1.10%, and (4) 20.20 ± 0.22%, respectively. An increase in the level of genetic divergence along with an enhancement in taxon rank was previously reported for different species, which might be explained by prevalence of geographic speciation model in nature. Phylogenetic trees were constructed using four approaches: maximum parsimony, Bayesian, maximum likelihood, and neighbor-joining. These trees demonstrated similar results confirming the monophyletic origin of the families studied. The examined representatives of the flatfish species and genera were shown to be sufficiently divergent genetically.     

贵州松桃寒武系清虚洞组Mongolitubulus squamifer 壳体显微结构初步研究

本文主要对贵州松桃寒武系清虚洞组灰岩中酸泡获得的管状化石Mongolitubulus squamifer壳体显微及亚显微结构进行研究。研究结果显示, M. squamifer不仅内层广泛发育纵向纤维结构,具鳞片的外层外壁也发育有微弱的纵向纤维结构,可能解释了管体外壁广泛发育的纵向开裂现象。在一枚保存有圆卵形鳞片以下部位的标本中发现,鳞片排列形式是由基部密集的小瘤点状颗粒然后过渡为不规则的圆卵形鳞片,到管体中上部逐渐形成规则排列的三角形鳞片。通过测量部分已报道的M.squamifer管体宽度与鳞片宽度发现正常发育的棘刺,鳞片大小与管体宽度有一定相关性。贵州松桃的M.squamifer壳层原始结构为2层,包括致密的具鳞片的外层和具明显纵向纤维结构的内层,管体内外层之间发育空隙导致管体容易破损。一些标本近基部断口处的层间空隙容易被次生矿物充填,导致内层增厚致密纤维结构消失或产生中间填充层。该研究揭示了M.squamifer的鳞片排列特征和壳体微观结构,为解释其亲缘关系提供新的形态学证据。     

江西柘林水库鱼类群落结构及功能多样性分析

为了解江西柘林水库鱼类群落结构和多样性的时空变化特征,研究鱼类物种多样性和功能多样性的关系,于2020年9月至2021年4月在该水库调查分析了鱼类物种组成、优势度及群落物种多样性和功能多样性。结果表明,共采集鱼类53种,分属于5目12科36属。其中,鲤形目(38种)种类最多,占调查物种数的71.69%,柘林水库上、中、下游库区分别采集到鱼类36、40和32种,各库区均以鲤形目鱼类为主,分别占采集物种数的72.97%、85.00%和75.00%。优势物种主要是■(Hemiculter leucisculus)、鳙(Aristichthys nobilis)和黄尾鲴(Xenocypris davidi),重要种主要是草鱼(Ctenopharyngodon idella)、鲢(Hypophthalmichthys molitrix)、鳊(Parabramis pekinensis)、鲫(Carassius auratus)、蒙古红鲌(Erythroculter mongolicus)等。鱼类群落结构季节性差异大于空间格局差异,主要表现为秋季和冬季之间;生物多样性指数Margalef和功能丰富...     

Phylogenies from genetic and morphological characters do not support a revision of Gigasporaceae (Glomeromycota) into four families and five genera

The family Gigasporaceae consisted of the two genera Gigaspora and Scutellospora when first erected. In a recent revision of this classification, Scutellospora was divided into three families and four genera based on two main lines of evidence: (1) phylogenetic patterns of coevolving small and large rRNA genes and (2) morphology of spore germination shields. The rRNA trees were assumed to accurately reflect species evolution, and shield characters were selected because they correlated with gene trees. These characters then were used selectively to support gene trees and validate the classification. To test this new classification, a phylogenetic tree was reconstructed from concatenated 25S rRNA and β-tubulin gene sequences using 35% of known species in Gigasporaceae. A tree also was reconstructed from 23 morphological characters represented in 71% of known species. Results from both datasets showed that the revised classification was untenable. The classification also failed to accurately represent sister group relationships amongst higher taxa. Only two clades were fully resolved and congruent among datasets: Gigaspora and Racocetra (a clade consisting of species with spores having one inner germinal wall). Other clades were unresolved, which was attributed in part to undersampling of species. Topology of the morphology-based phylogeny was incongruent with gene evolution. Five shield characters were reduced to three, of which two were phylogenetically uninformative because they were homoplastic. Therefore, most taxa erected in the new classification are rejected. The classification is revised to restore the family Gigasporaceae, within which are the three genera Gigaspora, Racocetra, and Scutellospora. This classification does not reflect strict topology of either gene or morphological evolution. Further revisions must await sampling of additional characters and taxa to better ascertain congruence between datasets and infer a more accurate phylogeny of this important group of fungi.     

Genetic population structure and morphological characters of Japanese psychrolutids of genus <Emphasis Type="Italic">Malacocottus</Emphasis> (Scorpaeniformes: Psychrolutidae)

The genetic population structure and the diagnostic characters of Malacocottus gibber from the Japan Sea and Malacocottus zonurus from the Okhotsk Sea and the northwestern Pacific were compared. Analysis of the nucleotide sequences of the mitochondrial control region revealed no genetic differences between the populations of M. gibber and M. zonurus, even though most individuals of both the species were found to be morphologically distinct. Most of the Malacocottus gibber specimens had the typical morphological characters of this species, namely the absence of an accessory spine on the preopercle of both sides and the absence of modified body scales above the lateral line. All the specimens of M. zonurus had accessory spines on both sides, and most of them had modified body scales. The results of this study suggest that M. gibber should be treated as a subspecies or a synonym of M. zonurus. The nested clade analysis and the analysis of molecular variance (AMOVA) showed that the Japanese Malacocottus fishes are genetically homogenous over their geographical range. The mismatch distribution of the Japanese Malacocottus fishes indicated that a sudden population expansion had occurred recently. The contrast in phylogeographic structures between the Malacocottus fish and the zoarcid Bothrocara hollandi—the most dominant deep-sea demersal fish in the Japan Sea—might be attributed to the differences in the depths of the habitats and larval ecology between these two fishes.