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Zoology: Analysis of Complex Systems, ZACS

D A Blank
Compared to solitary species, social ungulates benefit from living in groups not only because of the "many eyes effect", when each individual devotes less time to vigilance and spends more time foraging and engaged in other activities, or of the "dilution effect", when the probability that any specific individual will be caught decreases with herd size, but also because of early alarm signals produced by conspecifics that provide enough time for a successful escape from predator attack. These signals can contain multiple messages about the category of the predator and the degree of risk...
May 18, 2018: Zoology: Analysis of Complex Systems, ZACS
Jonas O Wolff, Braxton Jones, Marie E Herberstein
The nature and size of attachments is a fundamental element of animal constructions. Presumably, these adhesive structures are plastically deployed to balance material investment and attachment strength. Here we studied plasticity in dragline anchorages of the golden orb web spider, Nephila plumipes. Specifically, we predict that spiders adjust the size and structure of dragline anchorages with load, i.e. spider mass. Mass was manipulated by attaching lead pieces to the spider's abdomen resulting in a 50 percent increase in mass...
May 17, 2018: Zoology: Analysis of Complex Systems, ZACS
Chunmian Zhang, Tinglei Jiang, Guanjun Lu, Aiqing Lin, Keping Sun, Sen Liu, Jiang Feng
Evolutionary biologists had a long-standing interest in the evolutionary forces underlying geographical variation in the acoustic signals of animals. However, the evolutionary forces driving acoustic variation are still unclear. In this study, we quantified the geographical variation in the peak frequencies of echolocation calls in eight Miniopterus fuliginosus bat colonies, and assessed the forces that drive acoustic divergence. Our results demonstrated that seven of the colonies had very similar peak frequencies, while only one colony was significantly higher than the others...
May 12, 2018: Zoology: Analysis of Complex Systems, ZACS
Anna Z Urbisz, Łukasz Chajec, Mana Ito, Katsutoshi Ito
In Thalassodrilides cf. briani, the paired ovaries are inconspicuous and polarized structures with developmental gradient of germ cells along their long axis. The about 300 germ cells in the ovary are consolidated into one syncytial cyst and each cell is connected to a common and branched mass of cytoplasm via one stable cytoplasmic bridge. The germ cells differentiate their fate into nurse cells and oocytes. Only one oocyte grows in a given time; it gathers cell organelles and yolk and then it detaches from the gonad...
May 12, 2018: Zoology: Analysis of Complex Systems, ZACS
Giovanni Bearzi, Dan Kerem, Nathan B Furey, Robert L Pitman, Luke Rendell, Randall R Reeves
The scientific study of death across animal taxa-comparative thanatology-investigates how animals respond behaviourally, physiologically and psychologically to dead conspecifics, and the processes behind such responses. Several species of cetaceans have been long known to care for, attend to, be aroused by, or show interest in dead or dying individuals. We investigated patterns and variation in cetacean responses to dead conspecifics across cetacean taxa based on a comprehensive literature review. We analysed 78 records reported between 1970 and 2016, involving 20 of the 88 extant cetacean species...
May 9, 2018: Zoology: Analysis of Complex Systems, ZACS
Haruhiko Yasumuro, Yuzuru Ikeda
We investigated the effects of environmental enrichment on the cognitive abilities of pharaoh cuttlefish, Sepia pharaonis, which were reared from day seven in four different environments: isolated, poor, standard, and enriched. First, we used "prawn-in-the-tube" to test whether environmental enrichment affects the ontogeny of learning and memory of S. pharaonis. The results showed that cuttlefish could usually learn the task regardless of their age and environment. At early age (74 - 81 d), cuttlefish from the isolated environment memorized the task for 24h...
May 5, 2018: Zoology: Analysis of Complex Systems, ZACS
Katarzyna Wołczuk, Maciej Ostrowski, Agnieszka Ostrowska, Teresa Napiórkowska
The alimentary tract of oxudercine gobies is characterized by a lack of an anatomically distinct stomach, owing to which they are classified as stomachless. Since the environment, food requirements, and feeding habits have a significant impact on the anatomy of the alimentary tract of fish, it was assumed that predominantly carnivorous, semi-terrestrial mudskippers would have a stomach. In order to verify this hypothesis, anatomical, histological, histochemical and ultrastructural analysis of the alimentary tract of the Atlantic mudskipper Periophthalmus barbarus was performed...
April 26, 2018: Zoology: Analysis of Complex Systems, ZACS
André Zehnder, Stephen Henley, Robert Weibel
The central Kalahari region in Botswana is one of the few remaining ecosystems with a stable lion population. Yet, relatively little is known about the ecology of the lions there. As an entry point, home range estimations provide information about the space utilization of the studied animals. The home ranges of eight lions in this region were determined to investigate their spatial overlaps and spatiotemporal variations. We found that, except for MCP, all home range estimators yielded comparable results regarding size and shape...
April 9, 2018: Zoology: Analysis of Complex Systems, ZACS
Hayley J Stannard, Melissa L Tulk, Melissa J Bortolazzo, Julie M Old
Spinifex hopping-mice (Notomys alexis) and plains mice (Pseudomys australis) are able to successfully occupy arid zones of Australia. We studied the digestive parameters and energy assimilation of captive spinifex hopping-mice and plains mice. The experiment consisted of six diets fed to the animals for periods of 12days per food type. On a dry matter basis, the plains mice consumed between 2.5 and 7.2% and the hopping-mice between 5.8 and 9.3% of their body mass in food per day. The body mass of the spinifex hopping-mice increased significantly on the sunflower seed diet, while body mass did not change significantly for the plains mice on any diet...
June 2018: Zoology: Analysis of Complex Systems, ZACS
Noa Katz, Tamar Dayan, Noga Kronfeld-Schor
Many factors affect individual fitness, but while some factors, such as resource availability, have received strong experimental support, others including interspecific competition have rarely been quantified. Nevertheless, interspecific competition is commonly mentioned in the context of reproductive success and fitness. In general, when reproduction is likely to fail, reproductive suppression may occur. We studied the golden spiny mouse (Acomys russatus) and the common spiny mouse (A. cahirinus; however, recent molecular analysis in spiny mice from Jordan and Sinai suggests this species is A...
June 2018: Zoology: Analysis of Complex Systems, ZACS
Christopher L Rowe
I estimated standard metabolic rates (SMR) using measurements of oxygen consumption rates of embryos and unfed, resting hatchlings of the diamondback terrapin (Malaclemys terrapin) three times during embryonic development and twice during the early post-hatching period. The highest observed SMRs occurred during mid to late embryonic development and the early post-hatching period when hatchlings were still reliant on yolk reserves provided by the mother. Hatchlings that were reliant on yolk displayed per capita SMR 135 % higher than when measured 25 calendar days later after they became reliant on exogenous resources...
April 2018: Zoology: Analysis of Complex Systems, ZACS
Matías Sebastián Mora, Federico Becerra, Aldo Iván Vassallo
The South American rodents of the genus Ctenomys (Rodentia, Hystricognathi), which use both forelimbs and incisors to dig, show strong, specialized morphological adaptations to living in the underground niche. In these rodents, the effectiveness of a bite - in this case the potential to inflict physical damage - mostly depends on the strength of the incisors (e.g. bending and torsion stresses) and the power of the masseteric muscle of the jaw. Ctenomys australis (the sand dune tuco-tuco) is a highly territorial subterranean rodent that builds large and exclusive burrow systems in coastal sand dunes found continuously along the Atlantic coast of the Buenos Aires province, Argentina...
April 2018: Zoology: Analysis of Complex Systems, ZACS
Corinna Bang, Tal Dagan, Peter Deines, Nicole Dubilier, Wolfgang J Duschl, Sebastian Fraune, Ute Hentschel, Heribert Hirt, Nils Hülter, Tim Lachnit, Devani Picazo, Lucia Pita, Claudia Pogoreutz, Nils Rädecker, Maged M Saad, Ruth A Schmitz, Hinrich Schulenburg, Christian R Voolstra, Nancy Weiland-Bräuer, Maren Ziegler, Thomas C G Bosch
From protists to humans, all animals and plants are inhabited by microbial organisms. There is an increasing appreciation that these resident microbes influence the fitness of their plant and animal hosts, ultimately forming a metaorganism consisting of a uni- or multicellular host and a community of associated microorganisms. Research on host-microbe interactions has become an emerging cross-disciplinary field. In both vertebrates and invertebrates a complex microbiome confers immunological, metabolic and behavioural benefits; conversely, its disturbance can contribute to the development of disease states...
April 2018: Zoology: Analysis of Complex Systems, ZACS
Leonid Frantsevich, Ludmilla Frantsevich
A dragonfly larva migrates from the water to the shore, perches on a plant stem and grasps it with strongly flexed legs. Adult legs inside the larval exoskeleton fit to the larval legs joint-to-joint. The adult emerges with stretched legs. During the molt, an imaginal leg must follow all the angles in exuvial joints. In turn, larval apodemes are withdrawn from imaginal legs. We visualized transient shapes of the imaginal legs by the instant fixation of insects at different moments of the molt, photographed isolated exuvial legs with the imaginal legs inside and then removed the exuvial sheath...
April 2018: Zoology: Analysis of Complex Systems, ZACS
Carolina Imhoff, Federico Giri, Pablo Siroski, Patricia Amavet
The heterogeneity of biotic and abiotic factors influencing fitness produce selective pressures that promote local adaptation and divergence among different populations of the same species. In order for adaptations to be maintained through evolutionary time, heritable genetic variation controlling the expression of the morphological features under selection is necessary. Here we compare morphological shape variability and size of the cephalic region of Salvator merianae specimens from undisturbed environments to those of individuals from disturbed environments, and estimated heritability for shape and size using geometric morphometric and quantitative genetics tools...
April 2018: Zoology: Analysis of Complex Systems, ZACS
Marcello Mezzasalma, Mirko Di Febbraro, Fabio Maria Guarino, Gaetano Odierna, Danilo Russo
In this work, we performed a biogeographic analysis with Bayesian binary MCMC (BBM) statistical dispersal-vicariance analysis (S-DIVA) and species distribution models (SDM) on three phylogenetically closely related Mediterranean whipsnakes (Hierophis gemonensis, H. carbonarius, H. viridiflavus), to investigate the pathways of their geographical diversification and locate putative refugial areas in the last glacial maximum (LGM). Our analysis suggests that the diversification processes between the studied species overall followed an east-west route, from eastern Greece to the Iberian Peninsula and continental France, highlighting a significant role of dispersal and vicariance processes at both inter- and intraspecific levels...
April 2018: Zoology: Analysis of Complex Systems, ZACS
Lorenzo Alibardi
The presence and localization of cystatin, a cysteine protease inhibitor involved in barrier formation in human and mice epidermis, has been studied in the epidermis of piscine and terrestrial vertebrates using a mouse monoclonal antibody. Cystatin has been localized by Immunostaining in the pre-corneous and corneous layers of monotreme, marsupial and placental mammals, and sparsely in the thin corneous layer of birds. Cystatin-immunolabeling is present in the pre-corneous and corneous layer of crocodilian and turtle epidermis, in the alpha-corneous layer and likely also in the beta-corneous layer of the epidermis in lizards, snakes and the tuatara...
April 2018: Zoology: Analysis of Complex Systems, ZACS
Ilse Corkery, Ben D Bell, Nicola J Nelson
A major focus in zoology is to understand the phenotypic responses of animals to environmental variation. This is particularly important when dealing with ectotherms in a thermally heterogenous environment. We measured body temperatures of a free-ranging, medium sized temperate reptile, the tuatara, Sphenodon punctatus, to investigate its thermal opportunities and the degree to which the animal actively regulates its body temperature. We found high variation in body temperature between individuals, but this variation could not be attributed to sex or body size...
April 2018: Zoology: Analysis of Complex Systems, ZACS
Manuela T Comelis, Larissa M Bueno, Rejane M Góes, S R Taboga, Eliana Morielle-Versute
The penis is the reproductive organ that ensures efficient copulation and success of internal fertilization in all species of mammals, with special challenges for bats, where copulation can occur during flight. Comparative anatomical analyses of different species of bats can contribute to a better understanding of morphological diversity of this organ, concerning organization and function. In this study, we describe the external morphology and histomorphology of the penis and baculum in eleven species of molossid bats...
April 2018: Zoology: Analysis of Complex Systems, ZACS
María Gabriela Perotti, Marcelo Fabián Bonino, Daiana Ferraro, Félix Benjamín Cruz
Ectotherms are vulnerable to climate change, given their dependence on temperature, and amphibians are particularly interesting because of their complex life cycle. Tadpoles may regulate their body temperature by using suitable thermal microhabitats. Thus, their physiological responses are the result of adjustment to the local thermal limits experienced in their ponds. We studied three anuran tadpole species present in Argentina and Chile: Pleurodema thaul and Pleurodema bufoninum that are seasonal and have broad geographic ranges, and Batrachyla taeniata, a geographically restricted species with overwintering tadpoles...
April 2018: Zoology: Analysis of Complex Systems, ZACS
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