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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...
March 14, 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 In turn, larval apodemes are withdrawn from imaginal legs.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...
February 23, 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...
February 21, 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...
February 15, 2018: Zoology: Analysis of Complex Systems, ZACS
C Imhoff, F Giri, P Siroski, P 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...
February 14, 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...
February 13, 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...
February 7, 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...
February 1, 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...
January 31, 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...
January 31, 2018: Zoology: Analysis of Complex Systems, ZACS
Raf Claes, Pieter G G Muyshondt, Joris J J Dirckx, Peter Aerts
High sound pressure levels (>120dB) cause damage or death of the hair cells of the inner ear, hence causing hearing loss. Vocalization differences are present between hens and roosters. Crowing in roosters is reported to produce sound pressure levels of 100dB measured at a distance of 1m. In this study we measured the sound pressure levels that exist at the entrance of the outer ear canal. We hypothesize that roosters may benefit from a passive protective mechanism while hens do not require such a mechanism...
February 2018: Zoology: Analysis of Complex Systems, ZACS
Kinga Skieresz-Szewczyk, Hanna Jackowiak, Marlena Ratajczak
The lingual nail as the cornified layer of the orthokeratinized epithelium in birds is responsible for the collection of solid food by pecking. The aim of the present study is to determine the manner of orthokeratinized epithelium development and assess the degree of readiness of the epithelium to fulfill its mechanical function at hatching. Three developmental phases are distinguished, i.e. embryonic, transformation and pre-hatching stage. In the embryonic stage lasting until day 13 of incubation the epithelium is composed of several layers of undifferentiated cells...
February 2018: Zoology: Analysis of Complex Systems, ZACS
V H Paiva, J A Ramos, C Nava, V Neves, J Bried, M Magalhães
At-sea distribution and trophic ecology of small seabird species (i.e.<100 g) is far less known when compared to their larger relatives. We studied the habitat use (spatial ecology) and isotopic niches (trophic ecology) of the endangered Monteiro's storm-petrel Hydrobates monteiroi during the incubation and chick-rearing periods of 2013. There was a sexual foraging segregation of Monteiro's storm-petrels during the breeding period (tracking data) but also during the non-breeding stage (stable isotope analysis)...
February 2018: Zoology: Analysis of Complex Systems, ZACS
Miriam M Morales, S Rocío Moyano, Agustina M Ortiz, Marcos D Ercoli, Luis I Aguado, Sergio A Cardozo, Norberto P Giannini
Leopardus wiedii (margay) is the only arboreal Neotropical felid able to climb head-first down trees, due to its ability to rotate its tarsal joint 180°. A closely related, similar-sized species, L. geoffroyi (Geoffroy's cat) exhibits more typical terrestrial habits and lacks the arboreal capabilities of L. wiedii. There is osteological evidence that supports a mechanical specialization of L. wiedii's tarsal joint for inversion, but there have been no studies on the myology of this specialization. Based on comparative gross-anatomy dissections of zeugo- and autopodial muscles related to the ankle joint of one margay specimen and two Geoffroýs cats, we identified myological specializations of L...
February 2018: Zoology: Analysis of Complex Systems, ZACS
Jéssica Fratani, María Laura Ponssa, Virginia Abdala
Tendons are directly associated with movement, amplifying power and reducing muscular work. Taking into account habitat and locomotor challenges faced by anurans, we identify the more conspicuous superficial tendons of a neotropical anuran group and investigate their relation to the former factors. We show that tendons can be visualized as an anatomical framework connected through muscles and/or fascia, and describe the most superficial tendinous layer of the postcranium of Leptodactylus latinasus. To analyze the relation between tendon morphology and ecological characters, we test the relative length ratio of 10 tendon-muscle (t-m) elements in 45 leptodactylid species while taking phylogeny into account...
February 2018: Zoology: Analysis of Complex Systems, ZACS
Loïc Kéver, Eric Parmentier, Sofie Derycke, Erik Verheyen, Jos Snoeks, Maarten Van Steenberge, Pascal Poncin
Since prezygotic rather than postzygotic barriers are believed to maintain the diversity of closely related sympatric cichlids, differences in phenotypic traits and reproductive behaviours are likely involved in maintaining species boundaries. Here, we focused on the reproductive behaviour of three Ophthalmotilapia species with distributions that only overlap on a small stretch of the shore line of Lake Tanganyika. Repeated introgression of mitochondrial DNA between these species was previously reported, which suggested they can hybridise...
February 2018: Zoology: Analysis of Complex Systems, ZACS
Marco Sannolo, Frederico M Barroso, Miguel A Carretero
Sister species living in sympatry offer the opportunity to study the degree of divergence in their ecological, physiological and life-history traits. It has been hypothesized that closely related species with overlapping distribution should differ in their niche to reduce competition for resources. Furthermore, the investigation of sympatric species may shed light on how they may coexist without outcompeting each other. In the present study, we assess the degree of physiological divergence in two sympatric lacertid lizards, Podarcis bocagei and Podarcis guadarramae lusitanicus...
February 2018: Zoology: Analysis of Complex Systems, ZACS
Marie Altmanová, Michail Rovatsos, Martina Johnson Pokorná, Milan Veselý, Florian Wagner, Lukáš Kratochvíl
Once believed to be restricted only to endotherms (mammals and birds), several poikilothermic amniote lineages have recently been documented to possess long-term evolutionary stability in their sex chromosomes. However, many important lineages were not included in these tests. Previously, based on molecular evidence, we documented the homology of well-differentiated sex chromosomes among seven families of iguanas (Pleurodonta), with basilisks (Corytophanidae) being the only exception, as the tested genes linked to X, but missing on the Y chromosome, in other iguanas were autosomal or pseudoautosomal in basilisks...
February 2018: Zoology: Analysis of Complex Systems, ZACS
Markus Krings, Laura Rosskamp, Hermann Wagner
Owls are known for their nocturnal hunting capability. Many owl species are able to localize prey in complete darkness just by hearing. Sound localization of strictly nocturnal owls is improved by asymmetrically arranged outer ears. According to Norberg (1977), who worked with adult owls, asymmetrical ears evolved at least four times independently among owls. What is unknown so far is how the ear asymmetry develops in the embryo. Here we examine the embryonic development of ear asymmetry in the American barn owl (Tyto furcata pratincola) in the frame of the 42 stages suggested by Köppl et al...
February 2018: Zoology: Analysis of Complex Systems, ZACS
Karine D Colpo, Laura S López-Greco
The physiological costs of reproduction can be measured as the energy allocated to reproductive activities. In fiddler crabs, females allocate energy to vitellogenesis and brooding, whereas males perform expensive courtship behaviors. We evaluated in a large-scale study the reproduction cost of females and males of Leptuca uruguayensis in a temperate estuary, where their reproductive efforts are synchronized in a short reproductive season. The reproductive investments (vitellogenesis, spermatophore production, and male reproductive behaviors) were measured and related to the dynamics of storage and expenditure of energy reserves (glycogen, total lipids, and total protein) in the hepatopancreas, ovary, and muscle of the enlarged cheliped, throughout one annual cycle...
January 11, 2018: Zoology: Analysis of Complex Systems, ZACS
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