scholarly journals Leptodactylus vastus (LEPTODACTYLIDAE) predation on an endemic frog, and a compilation of its diet

2021 ◽  
Vol 27 (1) ◽  
Author(s):  
Felipe Eduardo Alves Coelho ◽  
Felipe de Medeiros Magalhães ◽  
Aldenir Ferreira da Silva Neta ◽  
Ricardo Marques
Keyword(s):  
Body Size ◽  
Diet Composition ◽  
Prey Selection ◽  
Striking Difference ◽  
Basic Information ◽  
Widespread Species ◽  
Predation Event ◽  
Mouth Size ◽  
Opportunistic Predator ◽  
History Of

Diet composition constitutes basic information on the natural history of the species. Despite the amount of data acquired in the last years, much remains to be known specially for geographically widespread species. Here we compiled the available dietary items of Leptodactylus vastus and report the first predation event upon Rupirana cardosoi by a juvenile L. vastus. The fact these species are syntopic in the region probably resulted in this novel predation event. Different from previous L. vastus predation observations, the specimens we observed do not present a striking difference in body size, but L. vastus was able to almost swallow L. cardosoi, coherent with findings that mouth size is related to prey selection in anurans. Also, our literature review showed that L. vastus is a generalist and opportunistic predator, that prey upon small vertebrates (Amphibia, Squamata, and Mammalia).

Feeding ecology of the Brazilian silverside Atherinella brasiliensis (Atherinopsidae) in a sub-tropical estuarine ecosystem

2010 ◽  
Vol 91 (6) ◽  
pp. 1197-1205 ◽  
Author(s):  
R.F. Contente ◽  
M.F. Stefanoni ◽  
H.L. Spach
Keyword(s):  
Body Size ◽  
Trophic Level ◽  
Feeding Ecology ◽  
Diet Composition ◽  
Estuarine Ecosystem ◽  
Tropical Estuarine ◽  
Different Types ◽  
Opportunistic Predator ◽  
Gut Fullness ◽  
Terrestrial Insects

The feeding ecology of the Brazilian silverside, Atherinella brasiliensis, in a sub-tropical estuary of Brazil was investigated through the gut analysis of 1431 individuals. We described dietary composition and analysed seasonal, estuarine habitat, and body size variations in the diet; trophic level; feeding diversity; and gut fullness indices. Results reveal that A. brasiliensis is a typical, generalistic and opportunistic predator that makes use of a wide array of prey types (at least 89 different types), with zooplankton (mainly calanoids), diatoms, terrestrial insects, and plant detritus making up the bulk of the overall diet. The exotic calanoid Temora turbinata ranked as the primary prey. A wide feeding diversity (mean H′ = 2.26), low trophic level (mean TROPH = 2.57), and high gut replenishment were persistent across seasons and habitats. Diet composition varied largely and significantly with respect to habitat, season, and body size. A closer assessment showed that habitat and season had a stronger effect on diet than fish size.

Diet composition and prey selection of vendace Coregonus albula in the mesotrophic, temperate Lake Ostrowite (Northern Poland)

2008 ◽  
Vol 37 (1) ◽  
Author(s):  
Tomasz Kakareko ◽  
Paweł Napiórkowski ◽  
Jacek Kozłowski
Keyword(s):  
Diet Composition ◽  
Prey Selection ◽  
Temperate Lake ◽  
Coregonus Albula ◽  
Northern Poland ◽  
Mesotrophic Lake ◽  
Selection Of

Diet composition and prey selection of vendaceLake Ostrowite is a mesotrophic lake in Northern Poland 280.7 ha in area and 43 m deep at its deepest point. To study vendace (

Population Genetics ofCaenorhabditis elegans: The Paradox of Low Polymorphism in a Widespread Species

Genetics ◽  
2003 ◽  
Vol 163 (1) ◽  
pp. 147-157 ◽  
Author(s):  
Arjun Sivasundar ◽  
Jody Hey
Keyword(s):  
Genetic Variation ◽  
Microsatellite Loci ◽  
Population Expansion ◽  
Widespread Species ◽  
C Elegans ◽  
Model Research ◽  
The World ◽  
Natural Isolates ◽  
History Of ◽  
Low Levels

AbstractCaenorhabditis elegans has become one of the most widely used model research organisms, yet we have little information on evolutionary processes and recent evolutionary history of this widespread species. We examined patterns of variation at 20 microsatellite loci in a sample of 23 natural isolates of C. elegans from various parts of the world. One-half of the loci were monomorphic among all strains, and overall genetic variation at microsatellite loci was low, relative to most other species. Some population structure was detected, but there was no association between the genetic and geographic distances among different natural isolates. Thus, despite the nearly worldwide occurrence of C. elegans, little evidence was found for local adaptation in strains derived from different parts of the world. The low levels of genetic variation within and among populations suggest that recent colonization and population expansion might have occurred. However, the patterns of variation are not consistent with population expansion. A possible explanation for the observed patterns is the action of background selection to reduce polymorphism, coupled with ongoing gene flow among populations worldwide.

scholarly journals Diet composition and feeding habits of the eyespot skate, Atlantoraja cyclophora (Elasmobranchii: Arhynchobatidae), off Uruguay and northern Argentina

2016 ◽  
Vol 14 (3) ◽  
Author(s):  
Santiago A. Barbini ◽  
Luis O. Lucifora
Keyword(s):  
Body Size ◽  
Diet Composition ◽  
Prey Size ◽  
Prey Availability ◽  
Feeding Habits ◽  
Warm Season ◽  
Cold Season ◽  
The North ◽  
Multiple Hypothesis ◽  
Modelling Approach

ABSTRACT The eyespot skate, Atlantoraja cyclophora, is an endemic species from the southwestern Atlantic, occurring from Rio de Janeiro, Brazil, to northern Patagonia, Argentina. The feeding habits of this species, from off Uruguay and north Argentina, were evaluated using a multiple hypothesis modelling approach. In general, the diet was composed mainly of decapod crustaceans, followed by teleost fishes. Molluscs, mysidaceans, amphipods, isopods, lancelets and elasmobranchs were consumed in lower proportion. The consumption of shrimps drecreased with increasing body size of A. cyclophora. On the other hand, the consumption of teleosts increased with body size. Mature individuals preyed more heavily on crabs than immature individuals. Teleosts were consumed more in the south region (34º - 38ºS) and crabs in the north region (38º - 41ºS). Shrimps were eaten more in the warm season than in the cold season. Prey size increased with increasing body size of A. cyclophora , but large individuals also consumed small teleosts and crabs. Atlantoraja cyclophora has demersal-benthic feeding habits, shifts its diet with increasing body size and in response to seasonal and regional changes in prey availability and distribution.

scholarly journals Feeding Ecology of Short-Toed Snake-Eagle (Circaetus gallicus [Gmelin, 1788]) in the Montados of Iberian Peninsula

2020 ◽  
Vol 28 (2) ◽  
pp. 155-179
Author(s):  
Nuno Onofre ◽  
Luís Sampaio
Keyword(s):  
Relative Abundance ◽  
Diet Composition ◽  
Prey Species ◽  
Prey Selection ◽  
Prey Type ◽  
Generalist Predator ◽  
Important Prey ◽  
Psammodromus Algirus ◽  
Circaetus Gallicus ◽  
Water Snakes

The diet of Short-toed Snake-eagle (Circaetus gallicus) during the breeding season in an area dominated by cork and holm oak parkland forests (Montados) was analyzed in this study. As expected, results showed that snakes are the dominant prey in the diet of this eagle, comprising up to 92.5% of the identified items, if potential secondary prey species were excluded. The Montpellier Snake (Malpolon monspessulanus) was the most consumed one (42.2%), followed by the Ladder Snake (Zamenis scalaris) (28.0%), and the water snakes (Natrix spp.) (14.2%). According to the same criteria, lizards (mainly Psammodromus algirus) and mammals represent between 4.8 and 2.2%, respectively. Other animals such as pond turtle and amphibians are irregular prey (<1%), and no bird remains were found at all. Short-toed Snake-eagle is usually referred as a stenophagic predator where snakes are by far its most important prey type, and where within this taxonomic group it behaves as a generalist predator. In this study this premise was then tested comparing the relative abundance of the snake species with their proportion in the diet composition of the eagle in order to know whether or not prey selection exists with regard to the species of snakes in this region. Results point to a quite plausible "preference" for the Ladder Snake and an "avoidance" for the smooth snakes group (Macroprotodon brevis/Coronella girondica), and possibly for the Horseshoe Whip (Hemorrhois hippocrepis). The avoidance to the Horseshoe Whip must be indirect and habitat related, while in relation to the two smooth snakes it may be due in large extend to its small size, in particular.

scholarly journals Foraging behaviour and performance of steers from two local breeds (Asturian Valley and Asturian Mountain) grazing in Cantabrian (N Spain) summer pastures

2019 ◽  
Vol 17 (1) ◽  
pp. e0601
Author(s):  
Alicia Román-Trufero ◽  
Antonio Martínez ◽  
Luis M. M. Ferreira ◽  
Valentín García-Prieto ◽  
Rocío Rosa-García ◽  
...  
Keyword(s):  
Body Weight ◽  
Body Size ◽  
Diet Composition ◽  
Foraging Behaviour ◽  
Meat Production ◽  
Market Demand ◽  
Nutrient Requirements ◽  
Northern Spain ◽  
Sward Height ◽  
And Performance

Steer meat production in northern Spain is deficient to attend market demand. This research aimed to compare the foraging behaviour and production of yearling steers from two local breeds differing in body weight (BW), Asturian Valley (AV, 372 kg) and Asturian Mountain (AM, 307 kg), grazing in summer pastures consisting of 70% grassland and 30% heathland. Bodyweight gains from a total of 42 steers were recorded during four grazing seasons (from June to October). In two years, in July and September, plant community selection and diet composition were estimated by direct observation and using faecal markers, respectively. Grazing time increased from July to September (488 vs. 557 min/day; p<0.001) as sward height in the grassland decreased. Although AV steers grazed proportionally for longer on herbaceous pastures than AM steers (81.3 vs. 73.3%; p<0.05), no differences between breeds were found in diet composition. AM steers showed greater mean daily BW gains than AV steers (252 vs. 133 g/day; p<0.01). From June to August, steers from both breeds gained BW (487 vs. 360 g/day for AM and AV, respectively; p<0.01), but thereafter BW gains decreased (120 vs. –12 g/day for AM and AV, respectively; p<0.05), because of reduced availability of grassland herbage. Yearling steers from AM breed seem to be better suited to mountain conditions than those from AV breed, probably because of their smaller body size and lower total nutrient requirements for maintenance.

Challenges and advances in the study of pterosaur flight

2015 ◽  
Vol 93 (12) ◽  
pp. 945-959 ◽  
Author(s):  
K.M. Middleton ◽  
L.T. English
Keyword(s):  
Body Size ◽  
Size Range ◽  
Flapping Flight ◽  
Flight Mechanics ◽  
Wing Membrane ◽  
Membrane Function ◽  
Aerodynamic Modeling ◽  
History Of ◽  
Bone Loading

Pterosaurs have fascinated scientists and nonscientists alike for over 200 years, as one of the three known clades of vertebrates to have evolved flapping flight. The smallest pterosaurs were comparable in size to the smallest extant birds and bats, but the largest pterosaurs were vastly larger than any extant flier. This immense size range, coupled with poor preservation and adaptations for flight unknown in extant vertebrates, have made interpretations of pterosaur flight problematic and often contentious. Here we review the anatomical, evolutionary, and phylogenetic history of pterosaurs, as well as the views, perspectives, and biases regarding their interpretation. In recent years, three areas of pterosaur biology have faced challenges and made advances: structure of the wing membrane, function of the pteroid, body size and mass estimates, as well as flight mechanics and aerodynamics. Comparative anatomical and fossil study, simulated bone loading, and aerodynamic modeling have all proved successful in furthering our understanding of pterosaur flight. We agree with previous authors that pterosaurs should be studied as pterosaurs, a diverse but phylogenetically, anatomically, and mechanically constrained clade that can offer new insights into the diversity of vertebrate flight.

Gramsci undisabled

Modern Italy ◽  
2016 ◽  
Vol 21 (4) ◽  
pp. 345-360 ◽  
Author(s):  
David Forgacs
Keyword(s):  
Short Stature ◽  
Communist Party ◽  
Political Identity ◽  
Spinal Tuberculosis ◽  
Striking Difference ◽  
Antonio Gramsci ◽  
Communist Movement ◽  
History Of ◽  
The Way

Most books by or about Antonio Gramsci reproduce on their covers the same studio photograph dating from the early 1920s. It is a head and shoulders portrait showing Gramsci with longish hair, dark coat buttoned at the neck, unsmiling and looking into the camera through wire-rimmed glasses. This was also the image of him most commonly displayed in Communist Party branches all over Italy from the late 1940s to 1991. Yet if we compare it with other extant photographs of Gramsci, as well as with those of other revolutionary leaders adopted as iconic in the communist movement, we can see it differs from the former and resembles the latter in several ways. The most striking difference is the erasure of any sign of Gramsci’s bodily impairment: the curvature of the spine and short stature resulting from the spinal tuberculosis he had as a child. The article examines the history of this photograph and the way it became adopted as the approved image of Gramsci and considers what was at stake in removing from official memory a condition of disability that was central to his own personal and political identity.

scholarly journals Comparative Analysis of the Rattle Calls in Corvus and Nucifraga: The Effect of Body Size, Bill Size, and Phylogeny

The Condor ◽  
2003 ◽  
Vol 105 (1) ◽  
pp. 139-144 ◽  
Author(s):  
Paola Laiolo ◽  
Antonio Rolando
Keyword(s):  
Body Size ◽  
Spectral Properties ◽  
Evolutionary History ◽  
Acoustic Properties ◽  
Frequency Peak ◽  
History Of ◽  
Patterns And Processes ◽  
Bill Length ◽  
The Relationship ◽  
Study Species

Abstract We assessed the effect of body size and bill length on the acoustic properties of the rattle calls of 15 corvid species. First, we correlated body traits and the acoustic properties of rattles, regardless of the evolutionary history of the study species. Then we repeated the analysis, taking into account phylogeny and thus excluding its effect on morphological and acoustic characters. When the potential effects of phylogeny were ruled out, the second frequency peak was negatively correlated to body size. The carrying frequency also decreased with decreasing body size, but the relationship was weaker than that resulting from a phylogeny-free analysis. This pattern is consistent with the demonstrated body-size–frequency allometry in the vocalizations of many birds. Bill length also influenced rattle spectral properties. We emphasize that patterns and processes elucidated with comparative studies can be biased if species relatedness is not considered. Análisis Comparativo de las Llamadas de Matraqueo entre Corvus y Nucifraga: Efecto del Tamaño Corporal, Tamaño del Pico y Filogenia Resumen. Evaluamos el efecto del tamaño corporal y la longitud del pico sobre las propiedades acústicas de los llamados de matraqueo de 15 especies de córvidos. Primero, correlacionamos los caracteres corporales con las propiedades acústicas del matraqueo independientemente de la historia evolutiva de las especies estudiadas. Luego, repetimos el análisis tomando en cuenta la filogenia, excluyendo su efecto sobre los caracteres morfológicos y acústicos. Cuando los potenciales efectos filogenéticos fueron removidos, el segundo pico en la frecuencia se correlacionó negativamente con el tamaño corporal. La frecuencia principal también decreció con la disminución del tamaño corporal, pero esta relación fue más débil que la resultante de un análisis sin considerar la filogenia. Este patrón es consistente con la alometría entre el tamaño corporal y la frecuencia de las vocalizaciones de muchas aves. La longitud del pico también influyó sobre las propiedades espectrales del matraqueo. Enfatizamos que los patrones y procesos elucidados a través de estudios comparativos pueden encontrarse sesgados si no se consideran las relaciones entre las especies.

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