Carapace asymmetries in crabs

Crustaceana ◽  
2018 ◽  
Vol 91 (11) ◽  
pp. 1281-1290
Author(s):  
Federica Spani ◽  
Massimiliano Scalici
Keyword(s):  
Fluctuating Asymmetry ◽  
Statistical Analyses ◽  
Directional Asymmetry ◽  
Environmental Constraints ◽  
Soil Composition ◽  
Geometric Morphometric ◽  
The Right ◽  
Predatory Pressure

Abstract Through the geometric morphometric approach of the landmark-based method applied on adult right-handed specimens of Carcinus aestuarii, Liocarcinus depurator and Potamon fluviatile, statistical analyses showed significant outcomes for fluctuating asymmetry in the three studied species, and directional asymmetry only in P. fluviatile (that showed a less convex carapace shape on the right side, where larger chela occurred). Although these findings may be correlated to some environmental constraints, such as soil composition, refuge occurrence and predatory pressure, also other interpretations may be proposed.

scholarly journals Comparison of orbital asymmetries among some raptor species: “when size does not matter”

2020 ◽  
Vol 14 (1) ◽  
pp. 23-27
Author(s):  
Pere M. Parés-Casanova ◽  
Jordina Salas-Bosch
Keyword(s):  
Procrustes Analysis ◽  
Directional Asymmetry ◽  
Foraging Strategies ◽  
Tyto Alba ◽  
Geometric Morphometric ◽  
Bubo Bubo ◽  
Generalized Procrustes Analysis ◽  
Gyps Fulvus ◽  
Accipiter Nisus ◽  
The Right

Abstract A sample of 73 dry, well-preserved skulls was studied, representing various species of raptors with different foraging strategies. The sample included Accipiter nisus (n = 15), Buteo buteo (n = 13), Gyps fulvus (n = 24) and Neophron percnopterus (n = 5), Bubo bubo (n = 16) and Tyto alba (n = 2). Geometric morphometric methods were used to detect orbital asymmetries. On digital pictures of each skull side, a set of 16 semi-landmarks and two landmarks were located in order to describe the orbital ring. The variables were analysed based on Generalized Procrustes analysis. The morphometric data showed that the orbital asymmetry of raptors differed significatively between species, although directional asymmetry (e.g. left orbita systematically more developed than the right) appeared not to be correlated with orbital size. This indicates that larger orbitas do not lead to greater asymmetry. Differences between species should rather be explained by their foraging strategies and degree of visual obstruction in their natural environment.

scholarly journals No Directional Scapular Asymmetry among Tamarines of the Genus Saguinus (Primates: Callitrichidae)

2020 ◽  
pp. 7-13
Author(s):  
P. M. Parés- Casanova ◽  
J. F. Vélez- García
Keyword(s):  
Fluctuating Asymmetry ◽  
Lateral Surface ◽  
The Other ◽  
Directional Asymmetry ◽  
Geometric Morphometric ◽  
Terrestrial Locomotion ◽  
Developmental Variation ◽  
Morphometric Methods ◽  
Perfect Symmetry ◽  
Left Scapula

Bilateral asymmetry is defined as a deviation of a whole organism or a part of it from a perfect symmetry, and different categories can be recognized. One is the fluctuating asymmetry, defined as the random developmental variation of a trait (or character) that is expected to be perfectly symmetrical on average, and the other one is directional asymmetry, which occurs when one of the sides shows stronger morphological structures or marks than the other. The aim of this study was to determine the kind of scapula asymmetry in Saguinus scapulae. On lateral surface of each right and left scapula, a set of 5 landmarks and 3 curves with semi-landmarks along the margins, on a sample of 16 pairs from different Saguinus species, were considered. Asymmetries (fluctuating and directional) on size and shape of the scapulae were analysed by means of geometric morphometric methods. Directional asymmetry was not detected, demonstrating no side scapular shape bias. The absence of significant directional asymmetry may indicate a similar contralateral pattern of employment of the shoulder, at least for one-arm vertical suspension, as it needs stronger forces than those for terrestrial locomotion and thus would cause more asymmetry in case side loadings were different. To our knowledge, this is the first investigation on the symmetrical/asymmetrical nature of scapulae in Saguinus. Our findings increase knowledge and understanding of humeral joint and arboreal locomotion in primates.

scholarly journals Side Differences in the Skull of Sheep: An Assessment by Geometric Morphometrics

2020 ◽  
pp. 1-7
Author(s):  
P. M. Parés-Casanova ◽  
A. Tolić ◽  
R. Carnicero
Keyword(s):  
Fluctuating Asymmetry ◽  
Genetic Factors ◽  
Bilateral Symmetry ◽  
Directional Asymmetry ◽  
Two Dimensional ◽  
Geometric Morphometric ◽  
Dorsal Aspect ◽  
Morphometric Methods ◽  
Muscular Function ◽  
External Stimuli

Effects of perturbations during development can be due to environmental and/or genetic factors, resulting in increased developmental instability which in turn can be expressed as fluctuating asymmetry (FA), defined as the non-directional deviation (right-left differences) from bilateral symmetry. However, other asymmetry types can appear, such as and directional asymmetry (DA), characterized by a distribution skewed to one side (right or left) at the, which is originated as a response to external stimuli that affect differentially on both sides of the organism. In order to describe asymmetric patterns in the ovine skull, we studied 165 specimens from animals belonging to the sheep breed “Navarra” from North Spain, using geometric morphometric methods. On digital pictures, we analyzed two midline and 8 bilateral two-dimensional landmarks on skull dorsal aspect. Results showed that FA accounted for a reduced amount of total variation, while DA explained most of it. We suggest that the presence of side differences due to lateralized muscular function (mastication) is the most important factor in skull asymmetry. Obtained results should provide a basis for relating asymmetries to the mechanics of cranial skeletum in sheep.

scholarly journals Functional skull asymmetries in Carollia perspicillata (Phyllostomidae Gray, 1825: Carollinae)

2020 ◽  
Vol 64 (1) ◽  
pp. 37-42
Author(s):  
Pere M. Parés-Casanova ◽  
Gerard Otin
Keyword(s):  
Fluctuating Asymmetry ◽  
Directional Asymmetry ◽  
Functional Requirements ◽  
Carollia Perspicillata ◽  
Geometric Morphometric ◽  
Domestic Species ◽  
Cranial Asymmetry ◽  
Dorsal Aspect ◽  
Morphological Responses

Analysing asymmetry in wild or domestic species enables the evaluation of the morphological responses to functional requirements and/or stress. This report is a study of the cranial asymmetry of Seba's short-tailed bat Carollia perspicillata by means of geometric morphometric techniques. We studied three types of bilateral asymmetries -fluctuating asymmetry, directional asymmetry and antisymmetry- using 15 skull landmarks on dorsal aspect of 45 skulls of Carollia perspicillata (21 males and 24 females) from different localities in Colombia. Directional asymmetry appeared to be significant and clearly higher than fluctuating asymmetry, with the braincase presenting the larger variance. There were no differences between sexes. Echolocation has a great anatomical effect on the bat cranium, and this would explain detected asymmetry.

Food stress, nestling growth, and fluctuating asymmetry

2000 ◽  
Vol 78 (1) ◽  
pp. 28-35 ◽  
Author(s):  
Mark D Hovorka ◽  
Raleigh J Robertson
Keyword(s):  
Growth Rates ◽  
Fluctuating Asymmetry ◽  
Measurement Errors ◽  
Repeated Measurements ◽  
Tree Swallow ◽  
Directional Asymmetry ◽  
Stabilizing Selection ◽  
Character Size ◽  
Size Growth ◽  
The Right

It has been suggested that fluctuating asymmetry (FA) is an indicator of perturbed development. Our study tests the validity of a fundamental assumption of asymmetry theory: that environmental stress imposed during development increases FA. We deprived tree swallow (Tachycineta bicolor) nestlings of food for 3 h every morning from days 3 to 15 of brood age. We obtained 2 repeated measurements of the right and left ninth primaries, outer rectrices, and tarsi, and one measure of body mass on days 8, 12, and 16. Food-deprived nestlings had significantly smaller character sizes (all characters for all days), significantly lower wing and tail feather growth rates, and significantly higher tarsal and mass growth rates than control nestlings. However, food deprivation did not cause experimental nestlings to exhibit significantly greater FA than control nestlings. Nestling mass and FA were not associated within treatments or across broods, and brood size had no significant effect upon the character size, growth rate, or FA level in nestlings. Measurement errors were small and size scaling, antisymmetry, and directional asymmetry did not confound FA estimates. Our results suggest that the ninth primaries and outer rectrices of tree swallows are unreliable indicators of FA-stress relations because of strong stabilizing selection for symmetry in this aerially insectivorous species.

Geometric morphometric analysis of different species of Cyprideis deriving from the Early Pleistocene record of Greece.

2021 ◽  
Author(s):  
Ypermachia Dimitriou ◽  
Penelope Papadopoulou ◽  
Maria Kolendrianou ◽  
Maria Tsoni ◽  
George Iliopoulos
Keyword(s):  
Endemic Species ◽  
Early Pleistocene ◽  
Geometric Morphometric ◽  
Representative Species ◽  
Lower Pleistocene ◽  
Close Relationship ◽  
Outline Analysis ◽  
Geometric Morphometric Analysis ◽  
The Right ◽  
Of Greece

<p>The genus Cyprideis is one of the most widespread ostracod representative of the Pleistocene brackish palaeoenvironments. Especially <em>Cyprideis torosa </em>is often found in great numbers and even in monospecific taphocoenoses and for this reason its study is very useful for palaeoenvironmental reconstructions.  The identification of different species of Cyprideis is often complicated and needs careful morphology inspection. This becomes even more difficult in the case of endemic species which present significant similarities with each other.  In this work, we have studied and analyzed several  Cyprideis species (<em>C.torosa, C. frydaci, C.dictyoti, C. pannonica, C. elisabeta, C. seminulum, C. heterostigma</em>) deriving from brackish palaeoenvironments of a Lower Pleistocene marl sequence in Sousaki Basin (Northeastern Corinth Graben, Greece). More specifically size measurements and geometric morphometrics (lateral valve outline of both right and left valves as well as females and males) were used in order to attest the similarities and dissimilarities between the different species and draw conclusions about their origin.  According to the valve outline and the multivariate analysis a close relationship between the valve shape of all Cyprideis species can be noticed. <em>C. torosa</em> is commonly grouped with <em>C. pannonica</em> except in the male right valve where the two species show some differences.  The endemic species <em>C. frydaci</em> and <em>C. dictyoti</em> can be identified by the differences in the right valve of the male and female respectively.  The other species could not be substantially differentiated using just the outline analysis which possibly denotes their common genetic origin.  The valve outline has proved to be a very useful character for recognizing the different species especially when the two valves of both females and males are considered. More analyses of representative species of Miocene and Pliocene Cyprideis are needed in order to establish their phylogenetic relationships and draw conclusions about their common ancestor.</p>

scholarly journals Towards More Realistic Leaf Shapes in Functional-Structural Plant Models

Symmetry ◽  
2018 ◽  
Vol 10 (7) ◽  
pp. 278 ◽  
Author(s):  
Dominik Schmidt ◽  
Katrin Kahlen
Keyword(s):  
Fluctuating Asymmetry ◽  
Leaf Shape ◽  
Three Dimensional ◽  
Directional Asymmetry ◽  
The Novel ◽  
Shape Model ◽  
Plant Model ◽  
Virtual Plant ◽  
Perfect Symmetry

Fluctuating asymmetry in plant leaves is a widely used measure in geometric morphometrics for assessing random deviations from perfect symmetry. In this study, we considered the concept of fluctuating asymmetry to improve the prototype leaf shape of the functional-structural plant model L-Cucumber. The overall objective was to provide a realistic geometric representation of the leaves for the light sensitive plant reactions in the virtual plant model. Based on three-dimensional data from several hundred in situ digitized cucumber leaves comparisons of model leaves and measurements were conducted. Robust Bayesian comparison of groups was used to assess statistical differences between leaf halves while respecting fluctuating asymmetries. Results indicated almost no directional asymmetry in leaves comparing different distances from the prototype while detecting systematic deviations shared by both halves. This information was successfully included in an improved leaf prototype and implemented in the virtual plant model L-Cucumber. Comparative virtual plant simulations revealed a slight improvement in plant internode development against experimental data using the novel leaf shape. Further studies can now focus on analyses of stress on the 3D-deformation of the leaf and the development of a dynamic leaf shape model.

scholarly journals SUBSTITUSI PUPUK NPK DENGAN BOKASHI ECENG GONDOK (Eichhornia crassipes) PADA PEMBIBITAN TANAMAN LADA

2018 ◽  
Vol 14 (2) ◽  
pp. 128
Author(s):  
Putri Aulia Rahmah ◽  
Gusti Rusmayadi ◽  
Hilda Susanti
Keyword(s):  
Soil Water ◽  
Plant Height ◽  
Water Hyacinth ◽  
Dry Weight ◽  
Pepper Plant ◽  
Soil Composition ◽  
Media Composition ◽  
Inorganic Fertilizers ◽  
The Right ◽  
Pepper Plants

This study aims to obtain the right composition in the use of water hyacinth bokashi that can substitute inorganic fertilizer in pepper plants. This research was carried out using polybag at plantation CV location. Gunung Putri Martapura for 4 months from January to May 2018 with experimental design of Randomized Non-Factorial Complete (RAL) with 5 treatment of plant media composition, namely: p0 = soil + 100% NPK “Mutiara” (without water hyacinth bokashi); p1 = soil: water hyacinth bokashi (3: 1 / v: v) + 75% NPK “Mutiara”; p2 = soil: water hyacinth bokashi (2: 2 / v: v) + 50% NPK “Mutiara”; p3 = soil: water hyacinth bokashi (1: 3 / v: v) + 25% NPK “Mutiara”; p4 = soil: water hyacinth bokashi (1: 3 / v: v) (without NPK “Mutiara”). Each treatment was repeated 4 times so that the entire plot of the experiment was 20 plots. Each plot consists of 5 plants so that there are 100 plants in total. Observations were made on plant height, stem diameter, the number of leaves, length of the segment, sprout age, and dry weight of the plant. Based on the result of the research, the treatment of various plant media composition has no significant effect on plant height, stem base diameter, leaf number, and dry weight of plant, but significantly affect the age of sprout and length of pepper plant so it can be concluded that water hyacinth bokashi in early the growth of pepper plants cannot substitute inorganic fertilizers but can be complimentary of inorganic fertilizers. The best cultivation plant composition treatment on pepper seedling in this study was on soil composition: water hyacinth  bokashi  (3: 1, v: v) + 75% NPK “Mutiara” and on soil composition: water hyacinth bokashi (2:2; v: v) + 50% NPK “Mutiara”.

Classification of Landscape Sensitivity in the Territory of Cremona

2013 ◽  
Vol 4 (3) ◽  
pp. 63-79 ◽  
Author(s):  
Pier Luigi Paolillo ◽  
Umberto Baresi ◽  
Roberto Bisceglie
Keyword(s):  
Spatial Information ◽  
Analytical Techniques ◽  
Urban System ◽  
Multidimensional Analysis ◽  
Environmental Constraints ◽  
Synthetic Indicators ◽  
Territorial Planning ◽  
Landscape Sensitivity ◽  
The Right

Centrality of landscape, in territorial planning, has been influencing for years, the testing of innovative analytical techniques aimed to gather peculiarities of urban and suburban context. The advent of Spatial Information System created the possibility to produce more detailed studies analyzing a lot of information dealing with territorial phenomena of crucial importance in spatial planning. The development of analytical systems based on multidimensional analysis may represent the right way to synthesize different phenomena that interact locally, in order to obtain the intrinsic sensitivity of a specific landscape as a result. In the case of Cremona Urban Variant, the production of thematic maps has allowed the construction of six synthetic indicators, dealing with specific aspects of Cremona landscape. The indicators are: i) insularisation of non – built spaces, ii) morphological / structural values, iii) perceptual landscape aspects, iv) permanence of urban system, v) degree of imperativeness of environmental constraints, vi) integrity of land use.

Political responses to interdependence: what's “left” for the left?

1991 ◽  
Vol 45 (4) ◽  
pp. 539-564 ◽  
Author(s):  
Geoffrey Garrett ◽  
Peter Lange
Keyword(s):  
Statistical Analyses ◽  
Global Markets ◽  
Economic Interdependence ◽  
Supply Side ◽  
Economic Policies ◽  
Monetary Policies ◽  
Goods And Services ◽  
Industrial Democracies ◽  
World Markets ◽  
The Right

Heightened economic interdependence in recent years is commonly argued to have generated great pressures for convergence in economic policies across the advanced industrial democracies. Interdependence has clearly had a great impact on the types of economic policies that governments can pursue: they have been unable to pursue independent fiscal and monetary policies since the mid-1970s. Furthermore, all governments have been forced to attempt to promote the competitiveness of national goods and services in world markets and to increase the speed and efficiency with which national producers adjust to changes in global markets. There are, however, different policies consistent with these goals. Statistical analyses of economic policies since the mid-1970s show that governments of the left and the right continue to be able to enact distinctive supply-side policies that promote competitiveness and flexible adjustment and simultaneously further their partisan objectives.

Sign in / Sign up

Export Citation Format

Share Document