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Zoology: Analysis of Complex Systems, ZACS

Patrício A da Rocha, Arivania S Pereira, Saulo M Silvestre, José Paulo Santana, Raone Beltão-Mendes, Marlon Zortéa, Stephen F Ferrari
Until now, the consumption of leaves by bats has been considered rare or sporadic, even among the herbivorous families Pteropodidae and Phyllostomidae. Among the phyllostomids there are reports of folivory in the genera Artibeus and Platyrrhinus, based on opportunistic observations. Here, we conducted behavioural sampling using camera-trapping in the roost of a colony of Platyrrhinus lineatus already known to consume leaves during the dry and wet seasons, in order to investigate the frequency of leaf consumption, as well as eventual seasonal differences...
December 29, 2016: Zoology: Analysis of Complex Systems, ZACS
Diana Székely, Dan Cogălniceanu, Paul Székely, Mathieu Denoël
Understanding the way species with similar niches can coexist is a challenge in ecology. The niche partitioning hypothesis has received much support, positing that species can exploit available resources in different ways. In the case of secretive species, behavioural mechanisms of partitioning are still poorly understood. This is especially true for fossorial frogs because individuals hide underground by day and are active only during the night. We investigated the nocturnal activity and tested the niche partitioning hypothesis in two syntopic fossorial spadefoot toads (Pelobates fuscus and Pelobates syriacus) by examining interspecific variation in emergence from the soil...
December 19, 2016: Zoology: Analysis of Complex Systems, ZACS
Anna-Christin Joel, Anne Habedank, Jonas Hausen, Jörg Mey
Most spider species are solitary, and among the few social interactions among them, resource competition between females has received little attention. We discovered that females of the feather-legged spider Uloborus plumipes invade the orb webs of conspecifics and compete for webs. Following observations in the wild, intruder-defender interactions were studied in a terrarium and in controlled laboratory experiments. We found that contests for orb webs occurred spontaneously between adult females. Competitive interactions in U...
December 14, 2016: Zoology: Analysis of Complex Systems, ZACS
Theo Busschau, Werner Conradie, Adriaan Jordaan, Savel R Daniels
We examined species boundaries among two phylogenetically closely related and morphologically similar South African fossorial legless skink species, Acontias breviceps and Acontias gracilicauda. Samples of these two species were collected throughout their distribution ranges and sequenced for three DNA loci (two mitochondrial loci, 16S rRNA and cytochrome b (Cyt b), plus the nuclear locus prolactin). Phylogenetic relationships were determined using maximum parsimony, Bayesian inference and maximum likelihood analyses of the combined DNA sequence data set...
December 10, 2016: Zoology: Analysis of Complex Systems, ZACS
Tales V Pascini, Gustavo F Martins
In the female insect, the spermatheca is an ectodermal organ responsible for receiving, maintaining, and releasing sperm to fertilize eggs. The number and morphology of spermathecae vary according to species. Within the spermathecal lumen, substances in the semen and secretions from the spermathecal gland nourish the sperm. Thus, the spermatheca provides an appropriate environment that ensures the long-term viability of sperm. Maintaining sperm viability for long periods within the spermatheca is crucial for insect reproductive success; however, the details of this process remain poorly understood...
December 5, 2016: Zoology: Analysis of Complex Systems, ZACS
Stephanie Köhnk, Jürgen Baudewig, Dirk Brandis, Susann Boretius
Museum collections may be viewed as a unique window onto the diversity and the functional evolution of species on earth. Detailed information about the inner structure of many precious collectors' items is, however, difficult to gain without destruction of the objects of interest. Here we applied magnetic resonance imaging (MRI) to freshly fixed as well as century-old museum specimens and compared the effects of fixative (formalin, ethanol, mercury chloride) on the image quality. Three-dimensional (3D) reconstruction of MRI was exemplarily used to non-invasively visualize anatomical structures of the brachyuran species Ilia nucleus, Ozius guttatus and Austinograea williamsi...
November 24, 2016: Zoology: Analysis of Complex Systems, ZACS
Takeo Kuriyama, Jyunko Esashi, Masami Hasegawa
Brown and green are the most commonly imitated colors in prey animals because both colors occur in a range of habitats. Many researchers have evaluated survival with respect to background color matching, but the pigment cell mechanisms underlying such coloration are not known. Dorsal coloration of East Asian Takydromus lizards has shifted from green to brown or from brown to green on multiple occasions during the diversification of the genus, thus giving us an opportunity to examine the cellular mechanisms of background color matching...
November 21, 2016: Zoology: Analysis of Complex Systems, ZACS
Céline Neutens, Bart de Dobbelaer, Peter Claes, Dominique Adriaens
All syngnathid fishes are characterized by a tail with a vertebral column that is surrounded by dermal Plates - four per vertebra. Seahorses and pipehorses have prehensile tails, a unique characteristic among teleosts that allows them to grasp and hold onto substrates. Pipefishes, in contrast, possess a more rigid tail. Previous research (Neutens et al., 2014) showed a wide range of variation within the skeletal morphology of different members in the syngnathid family. The goal of this study is to explore whether the diversity in the three-dimensional (3D) shape of different tail types reflects grasping performance, and to what degree grasping tails occupy a different and more constrained diversity...
November 18, 2016: Zoology: Analysis of Complex Systems, ZACS
Magdalena Kowalska, Mateusz Hermyt, Weronika Rupik
The aim of this study was to evaluate two research hypotheses: H0-the embryonic pancreas in grass snakes develops in the same manner as in all previously investigated amniotes (from three buds) and its topographical localization within the adult body has no relation to its development; H1-the pancreas develops in a different manner and is related to the different topography of internal organs in snakes. For the evaluation of these hypotheses we used histological methods and three-dimensional (3D) reconstructions of the position of the pancreatic buds and surrounding organs at particular developmental stages and of the final position and shape of the pancreatic gland...
November 11, 2016: Zoology: Analysis of Complex Systems, ZACS
Joshua D Stewart, Edgar Mauricio Hoyos-Padilla, Katherine R Kumli, Robert D Rubin
Foraging drives many fundamental aspects of ecology, and an understanding of foraging behavior aids in the conservation of threatened species by identifying critical habitats and spatial patterns relevant to management. The world's largest ray, the oceanic manta (Manta birostris) is poorly studied and threatened globally by targeted fisheries and incidental capture. Very little information is available on the natural history, ecology and behavior of the species, complicating management efforts. This study provides the first data on the diving behavior of the species based on data returned from six tagged individuals, and an opportunistic observation from a submersible of a manta foraging at depth...
October 2016: Zoology: Analysis of Complex Systems, ZACS
Michael Beckert, Brooke E Flammang, Erik J Anderson, Jason H Nadler
Remora fishes have a unique dorsal suction pad that allows them to form robust, reliable, and reversible attachment to a wide variety of host organisms and marine vessels. Although investigations of the suction pad have been performed, the primary force that remoras must resist, namely fluid drag, has received little attention. This work provides a theoretical estimate of the drag experienced by an attached remora using computational fluid dynamics informed by geometry obtained from micro-computed tomography...
October 2016: Zoology: Analysis of Complex Systems, ZACS
Ana Isabel Fagundes, Jaime A Ramos, Urtelinda Ramos, Renata Medeiros, Vitor H Paiva
The breeding success of burrow-nesting seabirds may be influenced by both nest site characteristics and oceanographic conditions influencing food availability at sea. In this study we describe the breeding biology of the winter-breeding Macaronesian shearwater (Puffinus lherminieri baroli), including nest site characteristics and interspecific competition. We also evaluate the possible effects of changing oceanographic conditions on breeding phenology and breeding success. The study was carried out over two breeding seasons on two islands in the North Atlantic Ocean, Cima Islet and Selvagem Grande...
October 2016: Zoology: Analysis of Complex Systems, ZACS
Brooke E Flammang, George V Lauder
Most teleost fishes, like the bluegill sunfish Lepomis macrochirus, have multiple flexible fins that are used as modifiable control surfaces. This helps to make fish highly maneuverable, permitting behaviors like reversing direction of motion and swimming backwards without having to rotate body position. To answer the question of how fish swim backwards we used high-speed videography and electromyography to determine the kinematics and muscle activity necessary to produce reverse-direction propulsion in four bluegill sunfish...
October 2016: Zoology: Analysis of Complex Systems, ZACS
Emily M Standen, Trina Y Du, Philippe Laroche, Hans C E Larsson
Amphibious fishes show wide variation in form and function. Examination of terrestrial locomotion in fishes has largely focused on highly specialized taxa. From an evolutionary perspective we are interested in how relatively unspecialized fishes locomote when exposed to different terrestrial environments. In this study, we explore the locomotory repertoire of the basal actinopterygian Polypterus senegalus. We describe its terrestrial locomotory strategies on different surfaces and compare them with steady aquatic locomotion...
October 2016: Zoology: Analysis of Complex Systems, ZACS
Aleksandar Urošević, Maja D Slijepčević, Jan W Arntzen, Ana Ivanović
Body elongation in vertebrates is often related to a lengthening of the vertebrae and an increase in their number. Changes in the number and shape of vertebrae are not necessarily linked. In tailed amphibians, a change in body shape is mostly associated with an increase in the number of trunk and tail vertebrae. Body elongation without a numerical change of vertebrae is rare. In Triturus aquatic salamanders body elongation is achieved by trunk elongation through an increase in the number of trunk vertebrae...
October 2016: Zoology: Analysis of Complex Systems, ZACS
Sarah Hayer, Stephanie Köhnk, Susann Boretius, Dirk Brandis
In this study a new organization of the female reproductive organs of Eubrachyura is presented after using both histology and MRI and μCT analyses to investigate the morphology and function of the female reproductive organs of Dorippe sinica Chen, 1980. The reproductive organ is composed of two parts: an ectodermal sperm site and a mesodermal ovary. The ectodermal sperm storage site incorporates a concave vagina and a seminal receptacle, which is completely lined by cuticle and is not connected to the ovary...
October 2016: Zoology: Analysis of Complex Systems, ZACS
Eva Líznarová, Stano Pekár
Trophic specialists are expected to possess adaptations that increase the efficiency of handling preferred prey. Such adaptations may constrain the ability to utilise alternative prey. Here we tested whether the ant-eating spider Euryopis episinoides possesses metabolic specialisations with increased efficiency in utilising preferred prey and decreased efficiency in utilising alternative prey. In addition, we investigated the contribution of genetic variation via maternal effects. We reared E. episinoides spiders from the first instar on two different diets, either ants (preferred prey) or fruit flies (alternative prey)...
October 2016: Zoology: Analysis of Complex Systems, ZACS
Glenn J Tattersall
Extant endotherms have high rates of metabolism, elevated body temperatures, usually tight control over body temperature, and a reasonable scope for further increases in metabolism through locomotor activity. Vertebrate ectotherms, on the other hand, rely on behavioural thermoregulation and cardiovascular adjustments to facilitate warming, and generally lack specific biochemical and cellular mechanisms for sustained, elevated metabolism. Nevertheless, the ancestral condition to endothermy is thought to resemble that of many extant reptiles, which raises the question of the origins and selection pressures relevant to the transitional state...
October 2016: Zoology: Analysis of Complex Systems, ZACS
Miguel Lorenzale, Miguel A López-Unzu, M Carmen Fernández, Ana C Durán, Borja Fernández, M Teresa Soto-Navarrete, Valentín Sans-Coma
The cardiac outflow tract of chondrichthyans and actinopterygians is composed of a myocardial conus arteriosus and a non-myocardial bulbus arteriosus. In teleosts, the conus has been subjected to a reduction in size over the evolution in conjunction with the further development of the bulbus. Most studies on the outflow tract of the teleost heart refer to species of modern groups and are mainly devoted to the bulbus. Knowledge on the outflow tract of species belonging to early teleost groups is scarce. The aim here was to characterise the structure of the cardiac outflow tract of the silver arowana, a representative of the ancient teleost clade of the Osteoglossomorpha...
September 28, 2016: Zoology: Analysis of Complex Systems, ZACS
Marina Meireles Dos Santos, Fernanda Magalhães da Silva, Erika Hingst-Zaher, Fabio Andrade Machado, Hussam El Dine Zaher, Ana Lúcia da Costa Prudente
Neotropical "goo-eating" dipsadine snakes display a set of morphological and histo-chemical adaptations linked to the capture of their soft-bodied, viscous invertebrate prey. Within this group, species from the genus Sibynomorphus feed chiefly on snails and slugs. Here, we analyzed a series of skull and mandible characters in S. mikanii, S. neuwiedi and S. turgidus using geometric morphometrics, with the aim of assessing morphological adaptations related to slug- and snail-feeding in that genus. We further compared the results with Leptodeira annulata, a species that feeds on vertebrates...
September 28, 2016: Zoology: Analysis of Complex Systems, ZACS
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