scholarly journals Seasonal shape variations, ontogenetic shape changes, and sexual dimorphism in a population of land isopod Porcellionides pruinosus: a geometric morphometric study

2021 ◽  
Vol 82 (1) ◽  
Author(s):  
Tarek G. Ismail
Keyword(s):  
Sexual Dimorphism ◽  
Seasonal Variations ◽  
Body Shape ◽  
Morphological Changes ◽  
The Body ◽  
Present Species ◽  
Morphometric Study ◽  
Agricultural Field ◽  
Geometric Morphometric ◽  
Shape Changes

Abstract Background Isopods shape features are sensitive and respond to several selective pressures which may result in variations of these features. These pressures might reflect the heterogeneity of the environment where an animal lives. Land isopods Porcellionides pruinosus were collected from an agricultural field. Landmarks geometric morphometrics was applied to evaluate its shape changes during two different seasons. The present work aims to (i) assess and characterize morphological changes in body shape of P. pruinosus as a response to seasonal variations, (ii) determine differences in the body shape during ontogeny, (iii) examine the effect of intraspecific allometry to interpret the observed variations in the species, and (iv) clarify whether the body shape of P. pruinosus can be used as a sexual differentiating trait. Results Juveniles showed no seasonal variations in the body shape, which were detected among adults, females and males as shown by PCA, DFA, and MANOVA. The adult winter forms have large bodies, small heads, broad pereons, and short but wide telsons. The adult summer forms have small slender bodies, slightly stretched heads, and relatively long telsons. Juveniles’ growth to adulthood showed body shape changes in the head and pereon, that include shrank of the head in the anteroposterior direction and its level became slightly lower than the body. The pereon becomes broader and the two anterolateral projections of the first pereonite extend anteriorly, reaching a little beyond the posterior margin of the eyes. Present species showed a shape sexual dimorphism which includes the broader body and more convex pereon in females and a small waist between the second and third pleonites in males. Shape sexual dimorphism was attributed to reproductive activity. Both allometric trajectories of juveniles and adults (ontogenetic allometry) and of sexes (static allometry) were parallel. Conclusions The landmark geometric morphometric technique was able to reveal the seasonal shape variations in terrestrial isopod P. pruinosus. Also, this method provides information about shape variations between juveniles and adults, as well as about shape sexual dimorphism.

scholarly journals Morphological and Genetic Structure of Two Equivalent Astyanax Species (Characiformes: Characidae) in the Region of Paranaíba Arc

2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Renan Rodrigues Rocha ◽  
Rosana de Mesquita Alves ◽  
Rubens Pasa ◽  
Karine Frehner Kavalco
Keyword(s):  
Geometric Morphometrics ◽  
River Basin ◽  
Dna Sequences ◽  
Haplotype Network ◽  
River Basins ◽  
Molecular Data ◽  
The Body ◽  
Present Species ◽  
Body Depth ◽  
Geometric Morphometric

The Astyanax scabripinnis complex is composed of a large number of almost morphological indistinguishable species, including Astyanax paranae and Astyanax rivularis, which exist in the Paraná and São Francisco Basins, respectively, and sometimes are considered subspecies of the A. scabripinnis group or even are cited just as A. scabripinnis. The two river basins are separated by the Upper Paranaíba Arc, likely the main cause of the isolation of these species. We used geometric morphometric tools and DNA analyses of populations of both species to identify the differences between them. Geometric morphometrics separated the two species into distinct groups, whose main difference was the body depth. This is generally related to the speed of the water flow in the river basins. The maximum likelihood phylogram based on mitochondrial DNA sequences formed two main clades: one composed of the population of A. rivularis and the other, of A. paranae. In the haplotype network, the species were similarly separated into two groups from the same ancestral haplotype, with A. rivularis dispersing into two lineages in the São Francisco River Basin. The distribution of A. paranae is a consequence of a secondary dispersion event in the Paraná River Basin. It forms two lineages from a haplotype derived from the ancestor. The vicariant effect of separate basins, through the elevation of the Upper Paranaíba Arc, led to the allopatric speciation of the populations originating the present species. The results of geometric morphometrics and molecular data of the fish show the importance of this geological event in the biogeography and evolutionary history of the ichthyofauna of the region and indicate that the isolation of these species seems to be effective.

Anthropometric Changes in Spaceflight

2021 ◽  
pp. 001872082110490
Author(s):  
Karen S. Young ◽  
K. Han Kim ◽  
Sudhakar Rajulu
Keyword(s):  
Body Shape ◽  
Space Station ◽  
The Body ◽  
Anthropometric Measurements ◽  
Space Suit ◽  
Anthropometric Data ◽  
Linear Measurements ◽  
Flight Phase ◽  
Overall Design ◽  
Shape Changes

Objective This study aims to identify the change in anthropometric measurements during spaceflight due to microgravity exposure. Background Comprehensive and accurate anthropometric measurements are crucial to assess body shape and size changes in microgravity. However, only limited anthropometric data have been available from the astronauts in spaceflight. Methods A new photogrammetry-based technique in combination with a tape-measure method was used for anthropometric measurements from nine crewmembers on the International Space Station. Measurements included circumference and height for body segments (chest, waist, bicep, thigh, calf). The time-dependent variations were also assessed across pre-, in-, and postflight conditions. Results Stature showed a biphasic change with up to 3% increase at the early flight phase, followed by a steady phase during the remaining flight. Postflight measurements returned to a similar level of the preflight. Other linear measurements, including acromion height, showed similar trends. The chest, hip, thigh, and calf circumferences show overall decrease during the flight up to 11%, then returned close to the preflight measurement at postflight. Conclusion The measurements from this study provide critical information for the spacesuit and hardware design. The ground-based assessments for spacesuit fit needs to be revalidated and adjusted for in-flight extravehicular activities from this data. Application These data can be useful for space suit design as well as habitat, vehicle, and additional microgravity activities such as exercise, where the body shape changes can affect fit, performance, and human factors of the overall design.

scholarly journals Sexual dimorphism of the mandibular conformational changes in aging human adults: A multislice computed tomographic study by geometric morphometrics

PLoS ONE ◽  
2021 ◽  
Vol 16 (6) ◽  
pp. e0253564
Author(s):  
Leonor Costa Mendes ◽  
Julien Delrieu ◽  
Claudia Gillet ◽  
Norbert Telmon ◽  
Delphine Maret ◽  
...  
Keyword(s):  
Sexual Dimorphism ◽  
Conformational Changes ◽  
Sexually Dimorphic ◽  
Shape Variation ◽  
Geometric Morphometric ◽  
Computed Tomographic ◽  
Age Related ◽  
Human Adults ◽  
Geometric Morphometric Analysis ◽  
Shape Changes

The aging process has an impact on mandibular bone morphology and can therefore affect shape sexual dimorphism. Understanding the effect of senescence on mandibular shape changes is particularly important to correctly estimate the sex of an individual and predict age-related conformational modifications. The purpose of this study was to assess age-related changes in mandibular shape and sexual dimorphism. The study sample comprised 160 Multi Slice Computed Tomography examinations of individuals aged 40 to 79 years. Geometric morphometric analysis of fourteen osteometric landmarks was used to examine sexual dimorphism and patterns of mandibular shape variation with age. Results showed that mandibular sexual dimorphism of shape remained significant with aging. Conformational changes occurred between 50 and 70 years and were different for male and female individuals. Females presented earlier and more marked age-related shape changes than males. These observations suggest that mandibular senescence is a sexually dimorphic process since its onset, rate, and the areas subjected to conformational changes differ from male to female individuals. Senescence-related changes present substantial variability, and further investigation is required to determine precisely the age that marks their onset.

scholarly journals Reversible morphological changes in a juvenile marine fish after exposure to predatory alarm cues

2020 ◽  
Vol 7 (5) ◽  
pp. 191945
Author(s):  
Carlos Díaz-Gil ◽  
Josep Alós ◽  
Pablo Arechavala-Lopez ◽  
Miquel Palmer ◽  
Inmaculada Riera-Batle ◽  
...  
Keyword(s):  
Marine Fish ◽  
Body Shape ◽  
Sparus Aurata ◽  
Morphological Changes ◽  
The Body ◽  
Fish Predator ◽  
Individual Level ◽  
Recovery Potential ◽  
Controlled Conditions ◽  
The Individual

Chemical cues from predators induce a range of predator-induced morphological defences (PIMDs) observed across fish taxa. However, the mechanisms, consistency, direction and adaptive value of PIMDs are still poorly studied. Here, we have tested if predatory cues can induce changes in the body shape of the juvenile marine fish Sparus aurata reared under controlled conditions without the presence of predators by exposing individuals to the olfactory stimulus of a fish predator. We tested our hypothesis using a nested replicated before-after-control-impact experiment, including recovery (potential reversibility) after the cessation of the predator stimulus. Differences in the size-independent body shape were explored using landmark-based geometric morphometrics and revealed that, on average, individuals exposed to a predatory cue presented deeper bodies and longer caudal regions, according to our adaptive theoretical predictions. These average plastic responses were reversible after withdrawal of the stimulus and individuals returned to average body shapes. We, therefore, provide evidence supporting innate reversible PIMDs in marine naive fish reared under controlled conditions. The effects at the individual level, including fitness and the associated applied implications, deserve further research.

Variability of facial movements in relation to sexual dimorphism and age: three-dimensional geometric morphometric study

HOMO ◽  
2018 ◽  
Vol 69 (3) ◽  
pp. 110-117 ◽  
Author(s):  
J. Velemínská ◽  
S. Danková ◽  
M. Břízová ◽  
L. Červenková ◽  
V. Krajíček
Keyword(s):  
Sexual Dimorphism ◽  
Three Dimensional ◽  
Morphometric Study ◽  
Geometric Morphometric ◽  
Facial Movements

Evidence of a heritable component to body shape in the northern redbelly dace (Phoxinus eos)

1997 ◽  
Vol 75 (8) ◽  
pp. 1247-1253 ◽  
Author(s):  
C. Anna Toline ◽  
Allan J. Baker
Keyword(s):  
Body Shape ◽  
Natural Populations ◽  
The Body ◽  
Foraging Ability ◽  
Environmental Induction ◽  
Foraging Tactics ◽  
Selection For ◽  
Shape Changes ◽  
Common Laboratory

Hypotheses about the role of selection on body-shape evolution assume a heritable component to this phenotypic character. To examine the influence of environmental induction on body shape, offspring form two morphologically differentiated populations of northern redbelly dace (Phoxinus eos) were reared in a common laboratory environment. Additionally, shape changes were monitored over 3 consecutive years in six populations. Offspring reared in a common environment retained the body shape of individuals from their natal pond, and shape changes among fish in different ponds were maintained in natural populations over years. These results strongly suggest a heritable component to body shape in P. eos. These results complement earlier work examining foraging tactics as a potential selection pressure on body shape and support the conclusion that body-shape differences among fish in different ponds are being maintained by selection for foraging ability.

The Use of Geometric Morphometric Techniques to Identify Sexual Dimorphism in Gait

2016 ◽  
Vol 32 (5) ◽  
pp. 441-448 ◽  
Author(s):  
Claire Waldock ◽  
Nick Milne ◽  
Jonas Rubenson ◽  
Cyril Jon Donnelly
Keyword(s):  
Sexual Dimorphism ◽  
Principal Components Analysis ◽  
Principal Components ◽  
Body Shape ◽  
Stance Phase ◽  
Gait Cycle ◽  
Geometric Morphometric ◽  
Males And Females ◽  
Components Analysis ◽  
Shape And Size

This study attempts to apply geometric morphometric techniques for the analysis of 3D kinematic marker-based gait data. As a test, we attempted to identify sexual dimorphism during the stance phase of the gait cycle. Two techniques were used to try to identify differences in the way males and females walk without the results being affected by individual differences in body shape and size. Twenty-eight kinematic markers were placed on the torso and legs of 6 male and 8 female subjects, and the 3D time varying coordinates of the kinematic markers were recorded. The gait cycle trials were time-normalized to 61 frames representing the stance phase of gait, and the change in the shape of the configuration of kinematic markers was analyzed using principal components analysis to produce ‘gait signatures’ that characterize the kinematics of each individual. The variation in the gait signatures was analyzed with a further principal components analysis. These methods were able to detect significant sexual dimorphism even after the effects of sexual body shape and size differences were factored out. We discuss insights gained from performing this study which may be of value to others attempting to apply geometric morphometric methods to motion analysis.

scholarly journals Morphological responses of a stream fish to water impoundment

2010 ◽  
Vol 6 (6) ◽  
pp. 803-806 ◽  
Author(s):  
Travis C. Haas ◽  
Michael J. Blum ◽  
David C. Heins
Keyword(s):  
Native Species ◽  
Body Shape ◽  
The Body ◽  
Strongly Correlated ◽  
Geometric Morphometric ◽  
Physical Conditions ◽  
Dorsal Fin ◽  
Cyprinella Venusta ◽  
Dramatic Shift ◽  
Water Impoundment

Water impoundment imposes fundamental changes on natural landscapes by transforming rivers into reservoirs. The dramatic shift in physical conditions accompanying the loss of flow creates novel ecological and evolutionary challenges for native species. In this study, we compared the body shape of Cyprinella venusta collected from eight pairs of river and reservoir sites across the Mobile River Basin (USA). Geometric morphometric analysis of the body shape showed that river populations differ from reservoir populations. Individuals inhabiting reservoirs are deep-bodied and have a smaller head, a more anterior dorsal fin, a shorter dorsal fin base and a more ventral position of the eye than C. venusta in streams. The direction of shape divergence within reservoir–river pairs was consistent among pairs of sites, and the shape of C. venusta in reservoirs is strongly correlated with reservoir size. These findings show that physical characteristics of reservoirs drive changes in the morphological attributes of native fish populations, indicating that water impoundment may be an important, yet largely unrecognized, evolutionary driver acting on aquatic biodiversity.

Body shape evolution of Chromis and Azurina species (Percifomes, Pomacentridae) of the eastern Pacific

2013 ◽  
Vol 63 (2) ◽  
pp. 217-232 ◽  
Author(s):  
Rosalía Aguilar-Medrano
Keyword(s):  
Body Shape ◽  
Phylogenetic Signal ◽  
Molecular Data ◽  
The Body ◽  
Eastern Pacific ◽  
Morphological Pattern ◽  
Geometric Morphometric ◽  
Morphometric Variation ◽  
Size And Shape ◽  
Morphometric Analyses

Chromis is a circumglobal tropical and temperate genus with over 84 species of damselfishes. Studies based in osteological and molecular data have cited the relationship between Azurina and Chromis in the eastern Pacific. The main objectives of the study are: (1) to characterize size and shape in all Chromis and Azurina species of the eastern Pacific, (2) explore the phylogenetic signal of external morphology, and (3) present a hypothesis of the diversification process of this group. According to the results, there is no significant relationship between size and shape. The variation in body shape among all species is related to the height of the trunk, position of the snout and eye, and length of the caudal peduncle. The main morphologic variation between Azurina and Chromis is the degree of elongation of the body. Both Azurina species are closely related to C. punctipinnis and C. atrilobata. The morphological pattern of Azurina integrated it into Chromis. The phylogenetic pattern found by geometric morphometric analyses presented a high similarity with previous results based on molecular data. Phylogeny recovered two main clades, slender-bodied and deep-bodied species. This pattern of morphometric variation is closely related to exploitation of two different reef environments.

scholarly journals Geometric morphometric study of sexual dimorphism and its associated allometry in wings of Pelopidas thrax (Lep.: Hesperiidae)

2021 ◽  
Vol 7 (4) ◽  
pp. 391-407
Author(s):  
Ahlam Zerganipour ◽  
Mehdi Esfandiari ◽  
Mohammad Mahdi Rabieh ◽  
◽  
◽  
...  
Keyword(s):  
Sexual Dimorphism ◽  
Morphometric Study ◽  
Geometric Morphometric
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