Androgenization of Dominant Males in a Cichlid Fish: Androgens Mediate the Social Modulation of Sexually Dimorphic Traits

We present data on the relationship between social status and male secondary sex traits, both morphological and ethological, in Oreochromis mossambicus at the onset of sexual maturation. There is a differential expression of morphological (dorsal fin height, anal fin height, mandible width and premaxilla length) and behavioural (nuptial coloration, per cent time defending a territory, spawning pit volume, pit hovering and courtship rate) traits according to social status, with dominants presenting the highest expression of these dimorphic traits. Social status also affects the development of the genital papillae, which is considered to be a good predictor of androgen levels in cichlid fishes. The results support a causal model in which social status modulate androgen levels that in turn modulate the expression of behavioural and morphological male traits.     

Parameters of immune status and axes of morphological typology

A study of immunological parameters and axes of morphological status in adolescents showed that parameters of cellular or humoral immunity correlated with different axes of morphological typology. The immune status with suppressed T-cell immunity was associated with the mesomorphic axis of the somatotype and the expression of B-cell immunity was associated with the endomorphic axis of the somatotype. The correlations of immunological and serological parameters with somatotype axes indicate that individual typological variations in the immune status are essentially determined by morphological (constitutional) features of the body during puberty.     

Relations of the morphological characteristic latent structure and body posture indicators in children aged seven to nine years

With the aim of determining the connection between the indicators of body posture and latent structure of morphological variables in children aged 7 and 8 years, first and second grade of primary school, a set of 17 morphological measures and 12 body posture indicators were longitudinally applied to a sample of 110 boys and 114 girls. The latent structure of morphological variables in both sexes was defined by three factors but at a different order of significance: in boys, the order was longitudinal dimensionality, voluminosity, mass and subcutaneous fat tissue and transverse dimensionality, whereas in girls the order was voluminosity, mass and subcutaneous fat tissue, longitudinal dimensionality and transverse dimensionality. The latent structure of torax body posture indicator was defined by two factors, the status of body posture of the rear part of the thorax, and status of the body posture of the front part of the thorax. The results obtained by canonical correlation analysis between predictive variables, morphological latent structure and criterion variables, latent structure of thorax body posture indicators with two posture indicators of the chest and one of the foot status, showed two important pairs of canonical roots on each measurement, suggesting a significant association between these two sets of parameters.     

Some problems of the study and representation of Siberian flora biodiversity in connection with its conservation

The present knowledge of flora of Siberia is quite insufficient, which is a considerable obstacle to the detection of its biodiversity for conserving the gene pool. Planning conservation measures should be focused not only on species, but also on intraspecific taxa and their phylogenetic uniqueness. In the absence of genetic data, available morphological and geographical methods should be used, so that, when it is impossible to establish the actual origin and relationship of taxa, the existing morphological diverstity is at least represented, as far as it is known to be based on genetic diversity. Phenetic maps can be of much use in the study of intraspecific morphological diversity. The estimation of geographic variability and morphological diversity, as well as the evaluation of territories, can be based on such maps. To represent adequately the biodiversity existing within poorly studied, presumably hybrid plant groups, until actual origin and relationship are known, they should probably be forcedly and provisionally considered as a special type of hybrid complexes, representing the unclear present day taxonomic situation. Such complexes could include populations and individuals with morphological characters of two or more different species, until the systematic position of such populations and individuals is further explored. Until the actual taxonomic status and relationship of the components are established, they could be regarded as subspecies permitted by the Code, or as certain recorded morphological deviations from the type, without assigning any taxonomic status to them--depending on the available data on variability and distribution. In the future, the resulting provisional information on morphological diversity would help to concentrate the efforts of biologists, in possession of the newest methods, on the most important objects, and serve as the scientific base for effective measures aimed at the conservation and management of the vast gene pool of the Siberian flora.     

Deciphering the products of evolution at the species level: the need for an integrative taxonomy

Progress in molecular techniques together with the incorporation of phylogenetic analyses of DNA into taxonomy have caused an increase in the number of species’ discoveries in groups with morphological characters that are difficult to study or in those containing polytypic species. But some emerged criticisms plead for a taxonomic conservatism grounded either on the requirement of providing evidences of morphological distinctiveness or reproductive barriers to erect new species names. In a case study of taxonomic research on Neotropical frogs, we combine several lines of evidence (morphological characters, prezygotic reproductive isolation and phylogenetic analyses of mitochondrial DNA) to test the status of 15 nominal species and to assess the degree of agreement of the different lines of evidence. Our study reveals that morphology alone is not sufficient to uncover all species, as there is no other single line of evidence independently. Full congruence between lines of evidence is restricted to only four out of the 15 species. Five species show congruence of two lines of evidence, whereas the remaining six are supported by only one. The use of divergence in morphological characters seems to be the most conservative approach to delineate species boundaries because it does not allow the identification of some sibling reciprocally monophyletic species differing in their advertisement calls. The separate analysis of differences in advertisement calls (evidence of reproductive isolation) or of phylogenetic data alone also shows limitations, because they do not support some morphological species. Our study shows that only an integrative approach combining all sources of evidence provides the necessary feedback to evaluate the taxonomic status of existing species and to detect putative new ones. Furthermore, the application of integrative taxonomy enables the identification of hypotheses about the existence of species that will probably be rejected or changed, and those that can be expected to persist.     

The status of the genus Bostryx Troschel, 1847, with description of a new subfamily (Mollusca, Gastropoda, Bulimulidae)

The status of the genus Bostryx is discussed and, based on morphological and molecular data, restricted to a group of species related to Bostryx solutus, for which the new subfamily name Bostrycinae is introduced.     

Taxonomic Status of the Okhotsk Lumpsucker Eumicrotremus ochotonensis (Cyclopteridae,Cottoidei) with Redescription of E. derjugini

Journal of Ichthyology - The species status is justified for the Okhotsk lumpsucker Eumicrotremus ochotonensis based on the morphological characters. The differences from the closely related...     

Pre‐ and post‐mating reproductive barriers drive divergence of five sympatric species of Naryciinae moths (Lepidoptera: Psychidae)

The biological species concept suggests that species can be separated on the basis of reproductive isolation. However, because natural interbreeding capabilities are often unknown, differences in morphology are generally used to separate species. Alternatively, genetic dissimilarity is used to separate morphologically similar species. Many genetic markers, including the maternally inherited mitochondrial cytochrome oxidase I sequence, cannot show interbreeding and therefore species status of groups may remain unresolved. In species of the genera Dahlica and Siederia (Lepidoptera: Psychidae: Naryciinae) the lack of morphological distinction and unknown interbreeding has led to unclear and unresolved taxonomic status. Mitochondrial DNA sequences suggest five sexual species to occur in Finland. However, their species status remains unconfirmed, due to a lack of knowledge on interbreeding, unclear morphological distinction and the limited variation in mitochondrial DNA. We combine three methods, a cross‐mating experiment, an analysis of mitochondrial and nuclear DNA, and a detailed male genital morphological examination, to establish the species status of the five suspected species. All suspected species exhibit intraspecies mating preference, although several interspecies pairs readily produce offspring. The genetic analysis, however, fails to show hybrids or introgression, suggesting that both pre‐ and post‐copulation mechanisms isolate the species reproductively. Morphological analysis of the male genitalia confirms that the species have diverged. Our results highlight the need of combining behavioural, morphological and genetic methods to determine species status in challenging taxonomic groups. © 2014 The Linnean Society of London, Biological Journal of the Linnean Society, 2014, 112 , 584–605.     

A descriptive and comparative study of the deciduous dentition of prehistoric Ohio Valley Amerindians

The deciduous dentition of 58 individuals from groups of prehistoric Ohio Valley Amerindians (2,000 B.C.-1,600 A.D.) was measured for antero-posterior and bucco-lingual dimensions and scored for morphological characteristics and macroscopic pathology. Only five dimensions of the posterior teeth and the frequency of severe linear enamel hypoplasia showed significant differences in the groups. In all cases focal agriculturalists exhibited smaller teeth and a higher frequency of severe linear enamel hypoplasia. These findings are explained as the result of changing diet and food preparation techniques, and/or sampling bias in the earlier burial cult groups where primarily higher status individuals may be the representatives. Comparison of metric and morphological characteristics of the deciduous dentition in the prehistoric Amerindians and roughly contemporaneous European groups indicates morphological characteristics are the better means of discrimination.     

Evidence of parallel evolution in the dental elements of Sweetognathus conodonts

The repeated emergence of similar morphologies in the dental elements of Permian Sweetognathus conodonts has been a hypothesized example of parallel evolution. To test if morphological parallelisms occur between isolated Sweetognathus lineages, this study uses two-dimensional-based geometric morphometrics combined with a revised and expanded phylogeny of Permian Sweetognathus conodonts to quantify dental element trait distributions and compare the phenotypic trajectories between lineages. A hierarchical clustering method was used to identify recurrent species pairs based on principal component scores describing their morphological variation, with the further incorporation of widely used ecological metrics such as limiting similarity and morphological overlap. Our research implies that a major contributor to conodont diversity in Palaeozoic marine trophic networks is the emergence of recurrent parallel morphologies via disruptive and directional selection. This study illustrates the mechanisms through which conodonts achieved their status as hyper-diverse predators and scavengers, contributing substantially to the complexity of Palaeozoic marine communities.     

Redox status of equine seminal plasma reflects the pattern and magnitude of DNA damage in sperm cells

Antioxidant status of seminal plasma from 23 stallions was evaluated. We found a negative correlation between total antioxidant capacity (ABTS^•+ decolorization assay) and thiol content of seminal plasma, and sperm DNA damage (8-oxoG immunostaining, TUNEL reaction, comet assay). Low seminal redox status was the strongest correlated with 8-oxoG level which may indicate that seminal total antioxidant capacity influences mainly the formation of single strand DNA breaks in sperm cells. Since inter-individual differences in seminal antioxidant status were reported, we postulated that the redox status of seminal plasma may be an additional important parameter, both with sperm quantitative and morphological analysis, for evaluation of equine semen quality.     

An investigation of the mechanistic aspects of excitation energy redistribution following thylakoid membrane protein phosphorylation

Accompanying thylakoid membrane protein phosphorylation is a redistribution of energy between PS II and PS I; mechanistic aspects of this redistribution have been investigated in both a mature and a developing chloroplast system. Data are presented which suggest that the mechanism of these changes is dependent upon the developmental status and/or morphological characteristics of the chloroplast.     

Alterations of the actin polymerization status as an apoptotic morphological effector in HL-60 cells

The alterations of the cytoskeletal actin network have been implicated as a morphological effector in apoptosis. However, studies directly linking actin change to the morphological events in apoptosis are lacking. This study quantitatively examined the effect of actin alteration on the camptothecin (CPT)-induced apoptotic process in HL-60 cells. Actin alteration was induced by two distinctive types of agent: the polymerization-stimulating agent, Jasplakinolide (Jas), and the polymerization-blocking agent, cytochalasin B (CB). The actin polymerization status was measured by two complementary methods: the cell pellet-based DNase I inhibition method, and the individual cell-based quantitative fluorescence image analysis (QFIA) assay. Actin polymerization induced by Jas caused apoptosis directly. By contrast, CB, an actin polymerization-blocking agent, partially inhibited CPT-induced apoptosis. A similar inhibition of the CPT-induced apoptosis response was observed with a more specific actin depolymerization agent, cytochalasin E. The alterations of the actin polymerization status occurred in three sequential steps during the apoptotic process: first polymerization, followed by depolymerization, and finally degradation. However, compared with CPT-induced apoptosis, Jas-induced apoptosis was characterized by pronounced actin polymerization that corresponded morphologically with prominent membrane blebbing, but less apoptotic body formation. Furthermore, DNase I activity, which is normally inhibited by G-actin, was specifically detected in Jas-treated cells. These results show that the regulation of actin polymerization is an important apoptotic morphological effector, whereas the alterations of the actin polymerization status by chemicals have profound effects not only on altering the morphology of apoptotic cells, but on apoptosis induction in HL-60 cells as well.     

Deep molecular divergence in the absence of morphological and ecological change in the Californian coastal dune endemic trapdoor spider Aptostichus simus

Aptostichus simus is a trapdoor spider endemic to the coastal dunes of central and southern California and, on morphological grounds, is recognized as a single species. Mitochondrial DNA 16S rRNA sequences demonstrate that most populations are fixed for the same haplotype and that the population haplotypes from San Diego County, Los Angeles County, Santa Rosa Island, and Monterey County are extremely divergent (6-12%), with estimated separation times ranging from 2 to 6 million years. A statistical cluster analysis of morphological features demonstrates that this genetic divergence is not reflected in anatomical features that might signify ecological differentiation among these lineages. The species status of these divergent populations of A. simus depends upon the species concept utilized. If a time-limited genealogical perspective is employed, A. simus would be separated at the base into two genetically distinct species. This study suggests that species concepts based on morphological distinctiveness, in spider groups with limited dispersal capabilities, probably underestimate true evolutionary diversity.     

A reinvestigation into the taxonomic status of Riccia himalayensis and Riccia discolor based on scanning electron microscopic and chemotaxonomical studies

Riccia himalayensis St. (Ms.) Kashyap is a common species found in the Himalayas from the foot of the mountains to an altitude of 2743 m. Riccia discolor Lehm. et Lindb. on the other hand, is the common and most widely distributed monsoon species, that has been reported from both the western and eastern Himalayas, as well as from the plains of Assam, west Bengal, Madhya Pradesh, south India, etc. Dispute still exists regarding the taxonomic status of R. himalayensis , which is considered a synonym of R. discolor by some taxonomists, according to whom R. himalayensis has no specific status. This has led to a lot of errors in interpreting R. discolor . On the other hand many authors have considered R. himalayensis to be a composite species of R. discolor , R. billardieri and R. gangetica .
The present investigation was aimed to reinvestigate the taxonomic status of R. himalayensis and R. discolor based on morphological analysis of thallus and spore surface by light microscope and scanning electron microscopy (SEM) studies and biochemical analyses of the protein profile by SDS-PAGE. Results reveal that although the two species share certain common morphological features, they are two distinct species chemotaxonomically.     

Investigations of pod characters in the Vivieae

A study of the fruits of modern members of the Vicieae (vetch tribe) has been undertaken to seek morphological, micromorphological and anatomical criteria which may assist in the identification of the archaeological remains of pods and in particular ones that may be useful for the diagnosis of their wild or domesticated status. The study included wild and domesticated Pisum (peas), Lens (lentils) and Vicia (common vetch) and some of their wild relatives found in the Old World. The results show that the micromorphological features of the pod surface tend to be highly variable, and do not distinguish the taxa. Most importantly, the pods of less-developed domesticated taxa show no reduction in the number of fibrous layers in the pod wall compared with those of their closest wild relatives, and no morphological or anatomical evidence has been found to indicate the dehiscent or indehiscent status of a pod. This appears to challenge some of our accepted wisdom on the mechanics of legume dehiscence. Received August 8, 2001 / Accepted January 15, 2002