http://www.frontiersinzoology.com The most accessed research articles published by Frontiers in Zoology 2012-04-25T00:00:00Z IntroductionMale monogyny in the absence of paternal investment is arguably one of the most puzzling mating systems. Recent evidence suggests that males of monogynous species adjust their life-history and their mating decision to shifting spatial and temporal selection regimes. In the cannibalistic wasp spider Argiope bruennichi males can be either monogynous or mate with a maximum of two females. We studied factors underlying male mating decisions in a natural population over a whole mating season. We documented all matings and categorized the males into single-mated and double-mated monogynous as well as bigynous males. Results: We found that all categories were continuously present with relatively stable frequencies despite changes in the operational sex ratio. Males were more likely monogynous when copulating with relatively heavy and old females and otherwise bigynous. Conclusion: Our results imply that males make conditional mating decisions based on the quality of the first female they encounter but do not adjust their mating tactic to the local selection regime. http://www.frontiersinzoology.com/content/9/1/7 Klaas Welke Stefanie Zimmer Jutta Schneider Frontiers in Zoology 2012, null:7 2012-04-25T00:00:00Z doi:10.1186/1742-9994-9-7 Predictors of male faithfulness in Argiope bruennichi Mono and bi-gynous mating tactics coexist in Argiope bruennnichi populations, where males make mating decisions based on the size and age of the first female that they mate with, as well as temporal and state-related factors. /content/figures/1742-9994-9-7-toc.gif Frontiers in Zoology 1742-9994 ${item.volume} 7 2012-04-25T00:00:00Z PDF Background: Rescuing amphibian diversity is an achievable conservation challenge. Disease mitigation is one essential component of population management. Here we assess existing disease mitigation strategies, some in early experimental stages, which focus on the globally emerging chytrid fungus Batrachochytrium dendrobatidis. We discuss the precedent for each strategy in systems ranging from agriculture to human medicine, and the outlook for each strategy in terms of research needs and long-term potential. Results: We find that the effects of exposure to Batrachochytrium dendrobatidis occur on a spectrum from transient commensal to lethal pathogen. Management priorities are divided between (1) halting pathogen spread and developing survival assurance colonies, and (2) prophylactic or remedial disease treatment. Epidemiological models of chytridiomycosis suggest that mitigation strategies can control disease without eliminating the pathogen. Ecological ethics guide wildlife disease research, but several ethical questions remain for managing disease in the field. Conclusions: Because sustainable conservation of amphibians in nature is dependent on long-term population persistence and co-evolution with potentially lethal pathogens, we suggest that disease mitigation not focus exclusively on the elimination or containment of the pathogen, or on the captive breeding of amphibian hosts. Rather, successful disease mitigation must be context specific with epidemiologically informed strategies to manage already infected populations by decreasing pathogenicity and host susceptibility. We propose population level treatments based on three steps: first, identify mechanisms of disease suppression; second, parameterize epizootiological models of disease and population dynamics for testing under semi-natural conditions; and third, begin a process of adaptive management in field trials with natural populations. http://www.frontiersinzoology.com/content/8/1/8 Douglas Woodhams Jaime Bosch Cheryl Briggs Scott Cashins Leyla Davis Antje Lauer Erin Muths Robert Puschendorf Benedikt Schmidt Brandon Sheafor Jamie Voyles Frontiers in Zoology 2011, null:8 2011-04-18T00:00:00Z doi:10.1186/1742-9994-8-8 /content/figures/1742-9994-8-8-toc.gif Frontiers in Zoology 1742-9994 ${item.volume} 8 2011-04-18T00:00:00Z XML Background: Taxonomy is the biological discipline that identifies, describes, classifies and names extant and extinct species and other taxa. Nowadays, species taxonomy is confronted with the challenge to fully incorporate new theory, methods and data from disciplines that study the origin, limits and evolution of species. Results: Integrative taxonomy has been proposed as a framework to bring together these conceptual and methodological developments. Here we review perspectives for an integrative taxonomy that directly bear on what species are, how they can be discovered, and how much diversity is on Earth. Conclusions: We conclude that taxonomy needs to be pluralistic to improve species discovery and description, and to develop novel protocols to produce the much-needed inventory of life in a reasonable time. To cope with the large number of candidate species revealed by molecular studies of eukaryotes, we propose a classification scheme for those units that will facilitate the subsequent assembly of data sets for the formal description of new species under the Linnaean system, and will ultimately integrate the activities of taxonomists and molecular biologists. http://www.frontiersinzoology.com/content/7/1/16 Jose Padial Aurelien Miralles Ignacio De la Riva Miguel Vences Frontiers in Zoology 2010, null:16 2010-05-25T00:00:00Z doi:10.1186/1742-9994-7-16 /content/figures/1742-9994-7-16-toc.gif Frontiers in Zoology 1742-9994 ${item.volume} 16 2010-05-25T00:00:00Z XML Background: Interest in the placing of landmarks and subsequent morphometric analyses of shape for 3D data has increased with the increasing accessibility of computed tomography (CT) scanners. However, current computer programs for this task suffer from various practical drawbacks. We present here a free software tool that overcomes many of these problems. Results: The TINA Manual Landmarking Tool was developed for the digitization of 3D data sets. It enables the generation of a modifiable 3D volume rendering display plus matching orthogonal 2D cross-sections from DICOM files. The object can be rotated and axes defined and fixed. Predefined lists of landmarks can be loaded and the landmarks identified within any of the representations. Output files are stored in various established formats, depending on the preferred evaluation software. Conclusions: The software tool presented here provides several options facilitating the placing of landmarks on 3D objects, including volume rendering from DICOM files, definition and fixation of meaningful axes, easy import, placement, control, and export of landmarks, and handling of large datasets. The TINA Manual Landmark Tool runs under Linux and can be obtained for free from http://www.tina-vision.net/tarballs/. http://www.frontiersinzoology.com/content/9/1/6 Anja Schunke Paul Bromiley Diethard Tautz Neil Thacker Frontiers in Zoology 2012, null:6 2012-04-05T00:00:00Z doi:10.1186/1742-9994-9-6 /content/figures/1742-9994-9-6-toc.gif Frontiers in Zoology 1742-9994 ${item.volume} 6 2012-04-05T00:00:00Z XML Background: Taxonomy or biological systematics is the basic scientific discipline of biology, postulating hypotheses of identity and relationships, on which all other natural sciences dealing with organisms relies. However, the scientific contributions of taxonomists have been largely neglected when using species names in scientific publications by not citing the authority on which they are based.DiscussionConsequences of this neglect is reduced recognition of the importance of taxonomy, which in turn results in diminished funding, lower interest from journals in publishing taxonomic research, and a reduced number of young scientists entering the field. This has lead to the so-called taxonomic impediment at a time when biodiversity studies are of critical importance.Here we emphasize a practical and obvious solution to this dilemma. We propose that whenever a species name is used, the author(s) of the species hypothesis be included and the original literature source cited, including taxonomic revisions and identification literature - nothing more than what is done for every other hypothesis or assumption included in a scientific publication. In addition, we postulate that journals primarily publishing taxonomic studies should be indexed in ISISM.SummaryThe proposal outlined above would make visible the true contribution of taxonomists within the scientific community, and would provide a more accurate assessment for funding agencies impact and importance of taxonomy, and help in the recruitment of young scientists into the field, thus helping to alleviate the taxonomic impediment. In addition, it would also make much of the biological literature more robust by reducing or alleviating taxonomic uncertainty. http://www.frontiersinzoology.com/content/8/1/25 Heike Wagele Annette Klussmann-Kolb Michael Kuhlmann Gerhard Haszprunar David Lindberg Andre Koch J.Wolfgang Wagele Frontiers in Zoology 2011, null:25 2011-10-26T00:00:00Z doi:10.1186/1742-9994-8-25 /content/figures/1742-9994-8-25-toc.gif Frontiers in Zoology 1742-9994 ${item.volume} 25 2011-10-26T00:00:00Z XML Background: Invertebrate nervous systems are highly disparate between different taxa. This is reflected in the terminology used to describe them, which is very rich and often confusing. Even very general terms such as 'brain', 'nerve', and 'eye' have been used in various ways in the different animal groups, but no consensus on the exact meaning exists. This impedes our understanding of the architecture of the invertebrate nervous system in general and of evolutionary transformations of nervous system characters between different taxa. Results: We provide a glossary of invertebrate neuroanatomical terms with a precise and consistent terminology, taxon-independent and free of homology assumptions. This terminology is intended to form a basis for new morphological descriptions. A total of 47 terms are defined. Each entry consists of a definition, discouraged terms, and a background/comment section. Conclusions: The use of our revised neuroanatomical terminology in any new descriptions of the anatomy of invertebrate nervous systems will improve the comparability of this organ system and its substructures between the various taxa, and finally even lead to better and more robust homology hypotheses. http://www.frontiersinzoology.com/content/7/1/29 Stefan Richter Rudi Loesel Gunter Purschke Andreas Schmidt-Rhaesa Gerhard Scholtz Thomas Stach Lars Vogt Andreas Wanninger Georg Brenneis Carmen Doring Simone Faller Martin Fritsch Peter Grobe Carsten Heuer Sabrina Kaul Ole Moller Carsten Muller Verena Rieger Birgen Rothe Martin Stegner Steffen Harzsch Frontiers in Zoology 2010, null:29 2010-11-09T00:00:00Z doi:10.1186/1742-9994-7-29 /content/figures/1742-9994-7-29-toc.gif Frontiers in Zoology 1742-9994 ${item.volume} 29 2010-11-09T00:00:00Z XML Background: Echinoderms and chordates belong to the same monophyletic taxon, the Deuterostomia. In spite of significant differences in body plan organization, the two phyla may share more common traits than was thought previously. Of particular interest are the common features in the organization of the central nervous system. The present study employs two polyclonal antisera raised against bovine Reissner's substance (RS), a secretory product produced by glial cells of the subcomissural organ, to study RS-like immunoreactivity in the central nervous system of sea cucumbers. Results: In the ectoneural division of the nervous system, both antisera recognize the content of secretory vacuoles in the apical cytoplasm of the radial glia-like cells of the neuroepithelium and in the flattened glial cells of the non-neural epineural roof epithelium. The secreted immunopositive material seems to form a thin layer covering the cell apices. There is no accumulation of the immunoreactive material on the apical surface of the hyponeural neuroepithelium or the hyponeural roof epithelium. Besides labelling the supporting cells and flattened glial cells of the epineural roof epithelium, both anti-RS antisera reveal a previously unknown putative glial cell type within the neural parenchyma of the holothurian nervous system. Conclusion: Our results show that: a) the glial cells of the holothurian tubular nervous system produce a material similar to Reissner's substance known to be synthesized by secretory glial cells in all chordates studied so far; b) the nervous system of sea cucumbers shows a previously unrealized complexity of glial organization. Our findings also provide significant clues for interpretation of the evolution of the nervous system in the Deuterostomia. It is suggested that echinoderms and chordates might have inherited the RS-producing radial glial cell type from the central nervous system of their common ancestor, i.e., the last common ancestor of all the Deuterostomia. http://www.frontiersinzoology.com/content/6/1/11 Vladimir Mashanov Olga Zueva Thomas Heinzeller Beate Aschauer Wilfried Naumann Jesus Grondona Manuel Cifuentes Jose Garcia-Arraras Frontiers in Zoology 2009, null:11 2009-06-18T00:00:00Z doi:10.1186/1742-9994-6-11 /content/figures/1742-9994-6-11-toc.gif Frontiers in Zoology 1742-9994 ${item.volume} 11 2009-06-18T00:00:00Z XML Genetic studies have typically inferred the effects of human impact by documenting patterns of genetic differentiation and levels of genetic diversity among potentially isolated populations using selective neutral markers such as mitochondrial control region sequences, microsatellites or single nucleotide polymorphism (SNPs). However, evolutionary relevant and adaptive processes within and between populations can only be reflected by coding genes. In vertebrates, growing evidence suggests that genetic diversity is particularly important at the level of the major histocompatibility complex (MHC). MHC variants influence many important biological traits, including immune recognition, susceptibility to infectious and autoimmune diseases, individual odours, mating preferences, kin recognition, cooperation and pregnancy outcome. These diverse functions and characteristics place genes of the MHC among the best candidates for studies of mechanisms and significance of molecular adaptation in vertebrates. MHC variability is believed to be maintained by pathogen-driven selection, mediated either through heterozygote advantage or frequency-dependent selection. Up to now, most of our knowledge has derived from studies in humans or from model organisms under experimental, laboratory conditions. Empirical support for selective mechanisms in free-ranging animal populations in their natural environment is rare. In this review, I first introduce general information about the structure and function of MHC genes, as well as current hypotheses and concepts concerning the role of selection in the maintenance of MHC polymorphism. The evolutionary forces acting on the genetic diversity in coding and non-coding markers are compared. Then, I summarise empirical support for the functional importance of MHC variability in parasite resistance with emphasis on the evidence derived from free-ranging animal populations investigated in their natural habitat. Finally, I discuss the importance of adaptive genetic variability with respect to human impact and conservation, and implications for future studies. http://www.frontiersinzoology.com/content/2/1/16 Simone Sommer Frontiers in Zoology 2005, null:16 2005-10-20T00:00:00Z doi:10.1186/1742-9994-2-16 /content/figures/1742-9994-2-16-toc.gif Frontiers in Zoology 1742-9994 ${item.volume} 16 2005-10-20T00:00:00Z XML Background: Many coral reef fishes undergo habitat and diet shifts during ontogeny. However, studies focusing on the physiological and morphological adaptations that may prepare them for these transitions are relatively scarce. Here, we explored the body shape variation related to ontogenetic shifts in the ecology of the surgeonfish Acanthurus triostegus (Acanthuridae) from new settler to adult stages at Moorea Island (French Polynesia). Specifically, we tested the relationship between diet and habitat shifts and changes in overall body shape during the ontogeny of A. triostegus using a combination of geometric morphometric methods, stomach contents and stable isotope analysis. Results: After reef settlement, stable isotope composition of carbon and nitrogen revealed a change from a zooplanktivorous to a benthic algae diet. The large amount of algae (> 75% of stomach contents) found in the digestive tract of small juveniles (25-30 mm SL) suggested the diet shift is rapid. The post-settlement growth of A. triostegus is highly allometric. The allometric shape changes mainly concern cephalic and pectoral regions. The head becomes shorter and more ventrally oriented during growth. Morphological changes are directly related to the diet shift given that a small mouth ventrally oriented is particularly suited for grazing activities at the adult stage. The pectoral fin is more anteriorely and vertically positioned and its basis is larger in adults than in juveniles. This shape variation had implications for swimming performance, manoeuvrability, turning ability and is related to habitat shift. Acanthurus triostegus achieves its main transformation of body shape to an adult-like form at size of 35-40 mm SL. Conclusion: Most of the shape changes occurred after the reef colonization but before the transition between juvenile habitat (fringing reef) and adult habitat (barrier reef). A large amount of allometric variation was observed after diet shift from zooplankton to benthic algae. Diet shift could act as an environmental factor favouring or inducing morphological changes. On the other hand, the main shape changes have to be achieved before the recruitment to adult populations and start negotiating the biophysical challenges of locomotion and feeding in wave- and current-swept outer reef habitat. http://www.frontiersinzoology.com/content/9/1/8 Bruno Frédérich Orphal Colleye Gilles Lepoint David Lecchini Frontiers in Zoology 2012, null:8 2012-04-25T00:00:00Z doi:10.1186/1742-9994-9-8 /content/figures/1742-9994-9-8-toc.gif Frontiers in Zoology 1742-9994 ${item.volume} 8 2012-04-25T00:00:00Z PDF IntroductionHoney bees, Apis mellifera, have a diverse community of pathogens. Previous research has mostly focused on bacterial brood diseases of high virulence, but milder diseases caused by fungal pathogens have recently attracted more attention. This interest has been triggered by partial evidence that co-infection with multiple pathogens has the potential to accelerate honey bee mortality. In the present study we tested whether co-infection with closely related fungal brood-pathogen species that are either specialists or non-specialist results in higher host mortality than infections with a single specialist. We used a specially designed laboratory assay to expose honey bee larvae to controlled infections with spores of three Ascosphaera species: A. apis, the specialist pathogen that causes chalkbrood disease in honey bees, A. proliperda, a specialist pathogen that causes chalkbrood disease in solitary bees, and A. atra, a saprophytic fungus growing typically on pollen brood-provision masses of solitary bees. Results: We show for the first time that single infection with a pollen fungus A. atra may induce some mortality and that co-infection with A. atra and A. apis resulted in higher mortality of honey bees compared to single infections with A. apis. However, similar single and mixed infections with A. proliperda did not increase brood mortality. Conclusion: Our results show that co-infection with a closely related fungal species can either increase or have no effect on host mortality, depending on the identity of the second species. Together with other studies suggesting that multiple interacting pathogens may be contributing to worldwide honey bee health declines. Our results highlight the importance of studying effects of multiple infections, even when all interacting species are not known to be specialist pathogens. http://www.frontiersinzoology.com/content/9/1/5 Svjetlana Vojvodic Jacobus Boomsma Jorgen Eilenberg Annette Jensen Frontiers in Zoology 2012, null:5 2012-03-23T00:00:00Z doi:10.1186/1742-9994-9-5 /content/figures/1742-9994-9-5-toc.gif Frontiers in Zoology 1742-9994 ${item.volume} 5 2012-03-23T00:00:00Z PDF