Molecular separation of Oesophagostomum stephanostomum and Oesophagostomum bifurcum (Nematoda: Strongyloidea) from non-human primates.

The ITS-2 sequences for adult specimens of Oesophagostomum stephanostomum from the common chimpanzee and Oesophagostomum bifurcum from the Mona monkey were determined. For both species, the length and GC content of the ITS-2 sequences were 216 bp and 43%, respectively. While there was no unequivocal sequence difference among individual worms representing each of the two species, five (2.3%) interspecific nucleotide differences were detected. These differences were associated with the presence of unique restriction sites in the ITS-2 sequence of 0. stephanostomum for multiple endonucleases of diagnostic value for the differentiation of the two taxa by restriction analysis. Pairwise comparisons of the ITS-2 sequences of O. stephanostomum and O. bifurcum with published ITS-2 sequences for five different congeners indicated that these species from the subgenus Conoweberia are closely related, in accordance with previous morphological studies.     

PCR assay for the specific amplification of Oesophagostomum bifurcum DNA from human faeces

Oesophagostomiasis in humans due to infection with Oesophagostomum bifurcum (nodule worm) is of major human health significance in northern Togo and Ghana where the human hookworm, Necator americanus, also exists at high prevalence. Accurate diagnosis of O. bifurcum infection in humans is central to studying the epidemiology and controlling the parasite. To overcome limitations of current copro-diagnostic methods, we have developed an alternative, molecular approach. Utilising genetic markers in the second internal transcribed spacer (ITS-2) of ribosomal DNA, we have established a two-step, semi-nested PCR method for the specific amplification of minute amounts (fg) of O. bifurcum DNA from human faecal samples. Using a panel of 155 well-defined faecal and DNA samples, the assay achieved a sensitivity of 94.6% and a specificity of 100%. This PCR assay will be useful for the diagnosis of O. bifurcum infection and as a molecular tool for elucidating the epidemiology of human oesophagostomiasis.     

白腰雪雀分类地位的商榷

自腰雪雀Onychostruthus taczanowskii(Przewalski)的分类地位比较混乱.在早期的分类系统中,它被归属于雪雀属Montifringilla下.后期由于生态习性与行为特征的不同,被划分至地雀属Pyrgilauda下;又有将它划分为独立属--高原雀属Onychostruthus的观点.本文结合身体量衡度数值特征、外部形态特征以及遗传差异上的研究,综合探讨白腰雪雀的分类地位.对量衡度特征的因子分析发现:白腰雪雀与地雀属种类在体长、体重、翅长、尾长、嘴长与跗蹠长上明显不同,其体形明显偏大.形态特征的聚类分析显示:白腰雪雀与地雀属种类的平均特征差异为0.3902～0.5122,而这些种类间平均特征差异为0.1281～0.2195.比较属间差异发现:石雀Petronia petronia与地雀属种类为0.4878～0.5385,树麻雀Passer montanus与地雀属种类为0.4872～0.5610.麻雀属与石雀属为0.3415,这些结果显示自腰雪雀与地雀属种类的差异已经达到石雀属、麻雀属与地雀属属间的差异.通过比较白腰雪雀与石雀的遗传差异(0.2578),地雀属种类与石雀的遗传差异(0.2386～0.3193),发现白腰雪雀与地雀属种类具有较大的遗传差异(0.2267～0.3143),几近于地雀属与石雀属间的差异.综合量衡度、形态以及遗传等特征的分析结果,作者认为白腰雪雀与地雀属种类有较大的差异,两者间的差异已经达到了它们与近缘属石雀属和麻雀属间的差异,以及近缘属之间的差异,因此,建议白腰雪雀应作为一个独立的属,高原雀属Onychostruthus.     

Size polymorphism in Oncaea venusta Philippi, 1843 and the validity of O. frosti Heron, 2002: a commentary

The morphological characters used to describe Oncaea frosti Heron, 2002 (Copepoda, Poecilostomatoida), an Atlantic medium-sized form variant of O. venusta Philippi, 1843, appear to be inadequate in view of the great polymorphism known for this ubiquitous species. Comparative analysis of published and newly collected length data of O. venusta variants worldwide demonstrates that O. frosti cannot be unequivocally delineated in the Indo-West Pacific. The validity of O. venella Farran sensu Heron (2002) is questioned and comments are given on Heron's synonymization of O. venusta f.venella sensu Ferrari (1975) and sensu Böttger-Schnack (2001) with O. frosti. As long as the significance of the morphological characters used to separate O. venusta form variants is not substantiated by data emerging from alternative taxonomic methods, such as the analysis of gene sequences, the species names O. frosti and O. venella Farran sensu Heron (2002) are regarded as species inquirendae in the genus Oncaea.     

Morphological and molecular characterization of a natural hybrid betweenOrchis laxiflora andO. morio (Orchidaceae)

A putative natural hybrid betweenOrchis laxiflora andO. morio (Orchidaceae) from southern Italy, formerly known asO. alata, was characterized both on morphological and molecular grounds in order to confirm its hybrid status and to trace its maternal lineage. The morphological characters of the putative hybrid showed intermediacy between those of the parent species, and restriction fragment length polymorphism (RFLP) analysis of a region of the nuclear ribosomal DNA confirmed its hybrid origin. Chloroplast DNA RFLP analysis indicated thatO. morio provided the maternal genome.     

The early life history of two sympatric New Zealand octopuses: eggs and paralarvae of Octopus huttoni and Pinnoctopus cordiformis

This study combined morphological and morphometric information on egg clutches, egg capsules and paralarvae of two sympatric coastal octopuses from New Zealand waters, Octopus huttoni and Pinnoctopus cordiformis, to provide species-specific traits to identify their early life stages obtained from field surveys. Eggs of O. huttoni (2.5 mm length; 1 mm width) were entwined with one another forming strings that ranged from 11 to 25.8 mm in length. Eggs of P. cordiformis (6.4 mm length; 1.5 mm width) were significantly bigger than those of O. huttoni and were grouped in small clusters of about seven eggs. Paralarvae O. huttoni and P. cordiformis differed in hatching size (1.4 mm versus 3.1 mm mantle length), number of suckers per arm (four versus eight), number of lamellae per outer demibranch (five versus ten) and arrangements of chromatophores in the body surface (29 to 59 versus 91 to 179), respectively. The morphological traits described in hatchlings from the laboratory allowed comparisons with field-collected paralarvae, suggesting that such characters were reliable species-specific patterns to enable a consistent differentiation between the early life stages of these two sympatric species, even in the absence of the brooding female.     

Characterization of Otostrongylus circumlitus from Pacific harbor and northern elephant seals

Otostrongylus circumlitus (Railliet, 1899) from Pacific harbor seals (Phoca vitulina richardsi) and northern elephant seals (Mirounga angustirostris) were examined using morphological and molecular methods to determine whether northern elephant seals along the central California coast are infected by the same species of Otostrongylus as are Pacific harbor seals in the same area. Fixed nematodes were examined and measured using light microscopy. The polymerase chain reaction (PCR) was used to amplify and sequence the second internal transcribed spacer (ITS-2) and D3 expansion (26S) regions of ribosomal DNA of O. circumlitus from Pacific harbor and northern elephant seals. The ITS-2 region was also amplified from Parafilaroides sp. from the Pacific harbor seal, northern elephant seal, and California sea lion (Zalophus californianus) and used for restriction fragment length polymorphism (RFLP) analysis. Morphologically, it was not possible to distinguish O. circumlitus from Pacific harbor and northern elephant seals, and over a consensus length of 443 base pairs (bp) for ITS-2 and 321 bp for D3 the sequences of O. circumlitus from both hosts were identical. With the PCR-RFLP assay, it was possible to distinguish O. circumlitus from Parafilaroides sp. The results suggest that O. circumlitus is the same species in Pacific harbor and northern elephant seals, and molecular methods make it possible to distinguish this nematode from related nematodes.     

Avoiding injury and surviving injury: two coexisting evolutionary strategies in lizards

Congenital morphological differences between injured and intact individuals in a population may reflect adaptations to avoid injury, to survive injury, or both. We explore the possible occurrence of such adaptations, analysing the relationship between tail state (original, O; regenerated, R) and morphology (20 scale characters) in 23 taxa of Lacertidae. In some taxa, such as Acanthodactylus opheodurus , morphologies of O and R lizards differed significantly. In these, usually O individuals were morphologically typical (modal), while R individuals were extreme; in others, the contrary occurred. Indices of pattern similarity detected fewer differences between O and R lizards than those based on absolute values. We developed unbiased estimates of classification rates of discriminant analysis. The order of inclusion of characters in the discriminant functions of males and females of the same species differed more than the order for the same sex in other species. Some morphological differences between O and R lizards seem adaptive or linked by pleiotropy to adaptive traits. Congenital morphological differences between O and R lizards are probably more frequent than detected because we show that age and geographical heterogeneity of our samples are confounding factors to O–R differences. R-morphologies might reflect microevolution in favour of paedotypic forms, possibly possessing greater regenerating capacities than relatively more peratypic forms.  © 2003 The Linnean Society of London, Biological Journal of the Linnean Society , 2003, 78 , 307–324.     

Male differentiation patterns in two polyphenic sister species of the genus Onthophagus Latreille, 1802 (Coleoptera: Scarabaeidae): a geometric morphometric approach

This paper focuses on morphological (both shape and size ) differences that quite similar polyphenic sister species evolve during divergence processes. Traits were analysed using a geometrical morphometric approach, which has the ability to evidence also very subtle differences in shape. As a case study, we considered males of the dung beetle sister species pair Onthophagus taurus and Onthophagus illyricus (Coleoptera, Scarabaeidae); these species represent a typical example of polyphenic trait expression concerning the facultative development of horns and considerable body size differences. External shape morphology failed to discriminate O. taurus from O. illyricus , whereas the reproductive system shape showed significant interspecific discrimination power. However, the head of O. taurus was significantly larger than that of O. illyricus and the reverse was true for the elytra. The two species also showed different allometric values of the head with respect to body size. This complex pattern of interspecific morphological divergence is discussed in the light of the differential trait divergence rate hypothesis. In both species, differences between major and minor forms concern the overall shape of head and pronotum: we suggest that such different forms, which likely reflect morphological readjustment to accommodate horns of considerable bulk and disproportionate length, may be nevertheless advantageously used by the two male morphs in their alternative reproductive tactics. Male genitalia sizes were virtually constant with respect to body size; however, the ratio between phallotheca and body size was significantly higher in minor males, in keeping with the hypothesis of a higher investment in genitalia borne by this morph.     

Ecological parallelism and cryptic species in the genus Ophiothrix derived from mitochondrial DNA sequences

We addressed the long-standing problem of species assignment of two nominal species of the genus Ophiothrix (Echinodermata, Ophiuroidea) by phylogenetic analysis of a segment of the mitochondrial 16S rDNA. Our phylogeny identified two distinct mitochondrial lineages that do not correspond to the present species assignments. Individuals of the endemic Mediterranean species O. quinquemaculata were clustered with individuals of O. fragilis in both mitochondrial lineages. We thus suggest that these taxa are not biological species but ecotypes. Differences between the two ecotypes in morphological and physiological characteristics may be explained by adaptation to environmental conditions at different water depths. Despite the observed ecomorphological variability within each of the two major mitochondrial lineages, the large genetic distance (9.0-12.0%) between them does suggest the existence of two distinct biological species. Their reproductive isolation could result from differences in reproductive strategy rather than by ecological and/or morphological differentiation.     

Relative growth and morphological sexual maturity of the caridean shrimp Nematopalaemon schmitti (Decapoda: Caridea: Palaemonidae) in an upwelling region in the Western Atlantic*

In crustaceans, successful reproductive processes, such as the transition from juvenile to adult, exhibit important morphological changes that can be detected by analyzing relative growth. This study describes the relative growth of body structures in Nematopalaemon schmitti and its secondary sexual characteristics, and also estimates the morphological sexual maturity of this species in a region influenced by upwelling. The carapace length (CL), second pleuron length (PlL), cheliped carpus length (CaL), cheliped propodus length (PrL) and the length of appendix masculina (AML) of the shrimp were measured. The relationships that best demonstrated the changes in allometric coefficient between demographic categories were AML vs. CL for males, and PlL vs. CL for females. The estimated CL for morphological sexual maturity in males was 8.51 mm and 9.30 in females. Our results showed the appendix masculine and the second pleuron were secondary sexual characteristics that play roles in reaching the morphological sexual maturity necessary for reproductive success and to assure the life cycle of this species.     

根据核DNA的ITS序列的RFLP分析鉴定稻属CD染色体组物种

稻属物种的染色体组类型有10种,其中具CD染色体组的物种有3种(Oryza alta Swallen,O.grandiglumis(Doell)Prod.和O.latifolia Desv.),仅分布在美洲中部和南部.这3个种在形态上和稻属其他染色体组的种比较容易区别,但它们彼此之间鉴别比较困难.近年来的研究表明,O.alta和O.grandiglumis应归并为1个种(O.grandiglumis),而O.latifolia应保持不变.本文基于代表不同分布区11个样品的核糖体转录间隔区(ITS)的77个克隆序列数据,利用DNA Striderl.2软件进行了限制性酶切位点分析,提出了一个鉴别CD染色体组物种的方法.方法的具体步骤是:(1)用通用引物扩增ITS片段;(2)用特异性的限制性内切酶Fok Ⅰ和/或Dra Ⅲ消化PCR扩增产物;(3)用1%的琼脂糖电泳并根据消化产物的多态性特征来鉴别不同物种.基于本文提出的核糖体ITS限制性片段多态性(RLFP)分析,可以快速和可靠地将稻属CD染色体组物种区别开来.     

根据核DNA的ITS序列的RFLP分析鉴定稻属CD染色体组物种

稻属物种的染色体组类型有10种,其中具CD染色体组的物种有3种(Oryza alta Swallen,O.grandiglumis(Doell) Prod．和O.latifolia Desv．),仅分布在美洲中部和南部。这3个种在形态上和稻属其他染色体组的种比较容易区别,但它们彼此之间鉴别比较困难。近年来的研究表明,O.alta和O.grandiglumis应归并为1个种(O．gandiglumis),而O．latifolia应保持不变。本文基于代表不同分布区11个样品的核糖体转录间隔区(ITs)的77个克隆序列数据,利用DNA striderl.2软件进行了限制性酶切位点分析,提出了一个鉴别CD染色体组物种的方法。方法的具体步骤是：(1)用通用引物扩增ITS片段;(2)用特异性的限制性内切酶Fok I 和／或Dra III消化PCR扩增产物;(3)用1％的琼脂糖电泳并根据消化产物的多态性特征来鉴别不同物种。基于本文提出的核糖体ITS限制性片段多态性(RLFP)分析,可以快速和可靠地将稻属CD染色体组物种区别开来。     

Morphological,ecological and genetic aspects associated with endemism in the Fly Orchid group

The European genus Ophrys (Orchidaceae) is famous for its insect‐like floral morphology, an adaptation for a pseudocopulatory pollination strategy involving Hymenoptera males. A large number of endemic Ophrys species have recently been described, especially within the Mediterranean Basin, which is one of the major species diversity hotspots. Subtle morphological variation and specific pollinator dependence are the two main perceptible criteria for describing numerous endemic taxa. However, the degree to which endemics differ genetically remains a challenging question. Additionally, knowledge regarding the factors underlying the emergence of such endemic entities is limited. To achieve new insights regarding speciation processes in Ophrys, we have investigated species boundaries in the Fly Orchid group (Ophrys insectifera sensu lato) by examining morphological, ecological and genetic evidence. Classically, authors have recognized one widespread taxon (O. insectifera) and two endemics (O. aymoninii from France and O. subinsectifera from Spain). Our research has identified clear morphological and ecological factors segregating among these taxa; however, genetic differences were more ambiguous. Insights from cpDNA sequencing and amplified fragment length polymorphisms genotyping indicated a recent diversification in the three extant Fly Orchid species, which may have been further obscured by active migration and admixture across the European continent. Our genetic results still indicate weak but noticeable phylogeographic clustering that partially correlates with the described species. Particularly, we report several isolated haplotypes and genetic clusters in central and southeastern Europe. With regard to the morphological, ecological and genetic aspects, we discuss the endemism status within the Fly Orchid group from evolutionary, taxonomical and conservation perspectives.     

Molecular phylogeny and ecogeography of Onobrychis viciifolia Scop. (Fabaceae) based on nrDNA ITS sequences and genomic ISSR fingerprinting

In this study 40 specimens from 8 representative Iranian populations of Onobrychis viciifolia SCOP. were collected from their natural habitats. The specimens were biometrically assessed using 43 quantitative and 15 qualitative morphological characters. At each sample site we recorded ecogeographical variables. In order to evaluate the difference between the variation due to phenotypic responses and genetic adaptation, we generated nucleotide sequence data from the internal transcribed spacer of the nuclear rDNA genes (ITS) and carried out genomic fingerprints using inter‐simple sequence repeat PCR (ISSR). Cluster analysis of morphological characters divided the eight populations into three major groups. Leaf length, leaflet length and width, calyx length, plant height, and stem length were introduced as diagnostic characters for three different morphological groups. Furthermore, canonical correspondence analysis (CCA) of ecogeographical data showed correlations between morphological variations and ecogeographical factors. Clay%, saturation percentage (SP), total neutralizing value (TNV%), texture, minimum temperature, and geographic separation were the main environmental variables associated with morphological groups of O. viciifolia. ISSR analysis revealed three main groups which are in correspondence with morphological groups, indicating that the three morphological groups have been shaped by genetic and phenotypic responses to environmental conditions. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

河南省淮河流域鳑鲏亚科5种鱼形态差异分析

为进一步从可量性状比较中华鳑鲏(Rhodeus sinensis)、越南鱊(Acheilongnathus tonkinensis)、大鳍鱊(A. macropterus)、兴凯鱊(A. chankaensis)和斑条鱊(A. taenianalis)的种间形态差异, 丰富鳑鲏亚科鱼类的形态分类特征, 研究采用多变量形态度量学方法对河南省淮河流域这5种鱼的形态进行比较分析。结果表明: 这5种鱼在体宽/体长、头长/体长、吻长/体长、尾柄长/体长、背鳍基底长/体长、腹鳍长/体长、臀鳍长/体长和头长/吻长8个比值性状上存在极显著性差异(P< 0.01), 在全长/体长、体高/体长2个比值性状上存在显著性差异(P<0.05), 这些差异主要集中在鱼体的头部、尾部和鳍等部位。主成分分析、聚类分析和判别分析显示5种鱼存在显著性形态差异, 斑条鱊与越南鱊的差异程度最大, 与大鳍鱊差异程度最小。判别分析获得的判别准确率在82.35%—100.00%变化, 可以从一定的角度区分这5种鱼。     

Validity Analysis of the Morphological Identification of Three Highly Morphologically Similar Species Belonging to the Genus Niviventer (Rodentia: Muridae)

Cryptic species are prevalent among mammals, and identifying morphological methods or measurements that can effectively distinguish cryptic species has high significance in taxonomy. Three of the white-bellied rats, Niviventer confucianus, N. fulvescens and N. huang (Rodentia: Muridae), have such similar morphological characteristics that taxonomists have not been able to effectively identify them according to their morphologies. Recent studies have determined that the N. fulvescens species complex contains multiple species, indicating that previous morphological comparisons were potentially based on inaccurate species identifications, leading to false conclusions. To clarify whether the morphological differences among these three species can be used for identification, a variety of morphological methods and measurements were combined with molecular species identification to ensure accurate identifications prior to comparing morphological characteristics. The results showed that: (1) only N. confucianus has a white tail tip, distinguishing this species from the other two species but not N. fulvescens from N. huang; and (2) the tail length of N. fulvescens and ear length of N. confucianus are greater than those of the other species. Traditional morphological methods cannot differentiate these species well, with the discrimination rate reaching more than 90%; therefore, they can only be used as auxiliary methods for morphological identification. Additionally: (3) the geometric morphological results of the four skull views can be combined to distinguish the three species, among which the discrimination rate of lateral view of mandible reaches 98%, making it effective for differentiating these species; and (4) the phallic morphologies of the three species differed significantly in the presence of a dorsal groove, thickness of the distal baculum, and the positional relationship between the distal and proximal baccula; thus, this approach can completely distinguish these species. This study examines the applicability of various morphological measurements for the identification of highly morphologically similar species, provides a reference for distinguishing cryptic species produced by convergent evolution or incomplete differentiation by morphology, and suggests that phallic morphology should be the primary characteristic for differentiating such species in the future.

     

Morphological traits as predictors of diet and microhabitat use in a diverse beetle assemblage

We explored how morphological traits can complement phylogenetic information to extend our predictions of the ecology of a diverse beetle assemblage. We analysed ten morphological traits from an assemblage of 239 species from 35 families, and identified three axes of morphological variation that were independent of body length: (1) relative robustness; (2) relative appendage length; and (3) relative abdomen length. The trait associations defining these axes of morphological variation did not change after adjusting for family‐level phylogeny. We detected significant differences in morphological variation across the beetle assemblage according to diet and microhabitat use, and these patterns were only partially influenced by family membership. Further analysis within dominant families showed that species of Carabidae, Curculionidae, Scarabaeidae and Staphylinidae had greater body length in open versus tree litter microhabitat, and species of Carabidae and Curculionidae had greater relative robustness, but shorter relative appendage length, in open versus tree litter microhabitat. Although it is clear that family‐level phylogeny and morphology share some explanatory power for predicting the diet and microhabitat use by beetles, we demonstrate that body length, robustness and appendage length are correlated significantly with microhabitat use when comparing members of the same family. © 2011 The Linnean Society of London, Biological Journal of the Linnean Society, 2011, 102 , 301–310.     

The significance of morphological variation in the finch species on Gough, Inaccessible and Nightingale Islands, South Atlantic Ocean

Uni- and multivariate analyses were made of nine morphological characters on three species of finches Nesospiza acunhae (Inaccessible, Nightingale), N. wilkinsi (Nightingale) and Rowettia goughensis (Gough). The results of the univariate analysis were used to test four predictions about morphological changes with altered competitive backgrounds. Finch species that occur alone on an island or on an island where other finch species are rare have longer characters and more variable character distributions.
A multivariate analysis of six bill characters showed that the bill of Rowettia is more similar to that of acunhae than either is to wilkinsi. A multivariate analysis on wing length, tarsus length and hallux length shows that Rowettia is morphologically closer to wilkinsi than it is to acunhae. It is suggested that nothing is gained by treating the Gough I. finch as belonging to a monotypic genus.