Shape and size variations of Aegla uruguayana (Anomura, Aeglidae) under laboratory conditions: A geometric morphometric approach to the growth

Crustacean growth studies typically use modal analysis rather than focusing on the growth of individuals. In the present work, we use geometric morphometrics to determine how organism shape and size varies during the life of the freshwater crab, Aegla uruguayana Schmitt, 1942. A total of 66 individuals from diverse life cycle stages were examined daily and each exuvia was recorded. Digital images of the dorsal region of the cephalothorax were obtained for each exuvia and were subsequently used to record landmark configurations. Moult increment and intermoult period were estimated for each crab. Differences in shape between crabs of different sizes (allometry) and sexes (sexual dimorphism; SD) were observed. Allometry was registered among specimens; however, SD was not statistically significant between crabs of a given size. The intermoult period increased as size increased, but the moult frequency was similar between the sexes. Regarding ontogeny, juveniles had short and blunt rostrum, robust forehead region, and narrow cephalothorax. Unlike juveniles crabs, adults presented a well-defined anterior and posterior cephalothorax region. The rostrum was long and stylised and the forehead narrow. Geometric morphometric methods were highly effective for the analysis of aeglid-individual- growth and avoided excessive handling of individuals through exuvia analysis.

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A Comparison of Traditional and Geometric Morphometric Techniques for the Study of Basicranial Morphology in Horses: A Case Study of the Araucanian Horse from Colombia

Animals ◽

10.3390/ani10010118 ◽

2020 ◽

Vol 10 (1) ◽

pp. 118

Author(s):

Pere Miquel Parés-Casanova ◽

Arcesio Salamanca-Carreño ◽

René Alejandro Crosby-Granados ◽

Jannet Bentez-Molano

Keyword(s):

Geometric Morphometrics ◽

Domestic Animal ◽

New Techniques ◽

Geometric Morphometric ◽

Animal Populations ◽

Morphometric Methods ◽

Mature Group ◽

Geometric Morphometric Analysis ◽

Shape And Size

Skull size and shape have been widely used to study domestic animal populations and breeds. Although several techniques have been proposed to quantify cranial form, few attempts have been made to compare the results obtained by different techniques. While linear morphometrics has traditionally been used in breed characterization, recent advances in geometric morphometrics have created new techniques for specifically quantifying shape and size. The objective of this study was to compare two morphometric methods for their ability to describe external morphology. For this purpose, 20 skull specimens of adult male Araucanian horses were examined. Two age categories were established (the “mature group”, M3 not fully erupted to moderately worn, n = 7; and the “senile group”, M3 totally erupted and highly worn, n = 13). Both methods showed that there were statistical differences between generations, but discrimination rates were different between methods with the geometric morphometric analysis obtaining a rate of 97.5%. Although linear morphometrics was found to be compatible with geometric morphometrics, the latter was better able to discriminate the two groups and it also provides more information on shape.

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No functional sexual dimorphism in Minorcan horse assessed by geometric morphometric methods

Animal Genetic Resources/Ressources génétiques animales/Recursos genéticos animales ◽

10.1017/s2078633614000514 ◽

2015 ◽

Vol 56 ◽

pp. 91-95 ◽

Cited By ~ 3

Author(s):

Pere M. Parés-Casanova ◽

C. Allés

Keyword(s):

Sexual Dimorphism ◽

Lateral View ◽

Geometric Morphometric ◽

Male And Female ◽

Size And Shape ◽

Morphometric Methods ◽

Nw Mediterranean ◽

Nw Mediterranean Sea ◽

Age Range ◽

Shape And Size

SummaryThe existence of sexual dimorphism in the Minorcan horse, an autochthonous breed from Minorca Island in the Balearic archipelago (NW Mediterranean Sea), is established in the official standard, with females being shorter and longer than males as well as having slenderer necks and a squarer croup. However, no study so far has explored the size and shape components of this dimorphism separately. The aim of this study was to analyse the morphology of this breed using geometric morphometric methods in order to find size and shape differences between sire lines. The analysis was based on landmarks digitized in lateral view from 38 registered adult Minorcan horses (20 males and 18 females) within an age range of 3–14 years (average 7 years) with different performance goals. The analyses did not reveal any significant differences between the “shape” and “size” of male and female animals, for the landmarks studied, so the sexes are functionally similar.

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New Geometric Morphometric Insights in Digital Taphonomy: Analyses into the Sexual Dimorphism of Felids through Their Tooth Pits

Applied Sciences ◽

10.3390/app11177848 ◽

2021 ◽

Vol 11 (17) ◽

pp. 7848

Author(s):

Darío Herranz-Rodrigo ◽

Silvia J. Tardáguila-Giacomozzi ◽

Lloyd A. Courtenay ◽

Juan-José Rodríguez-Alba ◽

Antonio Garrucho ◽

...

Keyword(s):

Sexual Dimorphism ◽

Geometric Morphometrics ◽

Applied Statistics ◽

Panthera Tigris ◽

Panthera Pardus ◽

Geometric Morphometric ◽

Male And Female ◽

New Horizons ◽

Carnivore Species ◽

Felid Species

Recent studies using geometric morphometrics for taphonomy have yielded interesting results, opening new horizons of research in both archaeological and paleontological sites. Here we present the analysis of tooth pits left by male and female individuals of two different carnivore species (Panthera tigris and Panthera pardus) in order to see if sexual dimorphism influences the morphology of tooth pit marks. In the process, 3D-scanning and applied statistics were used. Based on samples derived from two individuals of different sexes, the present results indicate sexual dimorphism in these felid species to not be a conditioning factor of tooth pit morphology.

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A Geometric Morphometric Assessment of Hand Shape and Comparison to the 2D:4D Digit Ratio as a Marker of Sexual Dimorphism

Twin Research and Human Genetics ◽

10.1017/thg.2013.5 ◽

2013 ◽

Vol 16 (2) ◽

pp. 590-600 ◽

Cited By ~ 3

Author(s):

Paul G. Sanfilippo ◽

Alex W. Hewitt ◽

Jenny A. Mountain ◽

David A. Mackey

Keyword(s):

Sexual Dimorphism ◽

Geometric Morphometrics ◽

Shape Analysis ◽

Twin Studies ◽

Analytical Techniques ◽

Shape Variation ◽

Geometric Morphometric ◽

Hand Shape ◽

Physical Traits ◽

Biological Shape

Twin studies are extremely useful for investigating hypotheses of genetic influence on a range of behavioral and physical traits in humans. Studies of physical traits, however, are usually limited to size-related biological characteristics because it is inherently difficult to quantify the morphological counterpart – shape. In recent years, the development of geometry-preserving analytical techniques built upon multivariate statistical methodologies has produced a new discipline in biological shape analysis known as geometric morphometrics. In this study of hand shape analysis, we introduce the reader already familiar with the field of twin research to the potential utility of geometric morphometrics and demonstrate the cross-discipline applicability of methods. We also investigate and compare the efficacy of the 2D:4D ratio, a commonly used marker of sexual dimorphism, to the fully multivariate approach of shape analysis in discriminating between male and female sex. Studies of biological shape variation utilizing geometric morphometric techniques may be completed with software freely available on the Internet and time invested to master the small learning curve in concepts and theory.

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The Utility of Geometric Morphometrics to Elucidate Pathways of Cichlid Fish Evolution

International Journal of Evolutionary Biology ◽

10.4061/2011/290245 ◽

2011 ◽

Vol 2011 ◽

pp. 1-8 ◽

Cited By ~ 22

Author(s):

Michaela Kerschbaumer ◽

Christian Sturmbauer

Keyword(s):

Geometric Morphometrics ◽

Evolutionary Biology ◽

Body Shape ◽

Cichlid Fish ◽

Anatomical Landmarks ◽

Trophic Specialization ◽

Geometric Morphometric ◽

The Family ◽

Morphometric Methods ◽

Head Morphology

Fishes of the family Cichlidae are famous for their spectacular species flocks and therefore constitute a model system for the study of the pathways of adaptive radiation. Their radiation is connected to trophic specialization, manifested in dentition, head morphology, and body shape. Geometric morphometric methods have been established as efficient tools to quantify such differences in overall body shape or in particular morphological structures and meanwhile found wide application in evolutionary biology. As a common feature, these approaches define and analyze coordinates of anatomical landmarks, rather than traditional counts or measurements. Geometric morphometric methods have several merits compared to traditional morphometrics, particularly for the distinction and analysis of closely related entities. Cichlid evolutionary research benefits from the efficiency of data acquisition, the manifold opportunities of analyses, and the potential to visualize shape changes of those landmark-based methods. This paper briefly introduces to the concepts and methods of geometric morphometrics and presents a selection of publications where those techniques have been successfully applied to various aspects of cichlid fish diversification.

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Studies on the life-cycle of Pleurogenoides ovatus Rao, 1977 (Trematoda: Pleurogenetinae)

Journal of Helminthology ◽

10.1017/s0022149x00010427 ◽

1991 ◽

Vol 65 (1) ◽

pp. 43-50 ◽

Cited By ~ 7

Author(s):

K. P. Janardanan ◽

P. K. Prasadan

Keyword(s):

Life Cycle ◽

Growth And Development ◽

Freshwater Snail ◽

Prepatent Period ◽

Paddy Fields ◽

Freshwater Crab ◽

Connective Tissues ◽

Life Cycle Stages ◽

Rana Tigrina

ABSTRACTThe life-cycle of Pleurogenoides ovatus Rao, 1977, infecting the frogs, Rana tigrina and R. cyanophlyctis has been elucidated. All the life-cycle stages from egg to egg-producing adults were successfully established in the laboratory. The life-cycle took about 80 days for completion. Cercariae were found in the freshwater snail, Digoniostoma pulchella, collected from paddy fields at Chelembra, Malappuram district of Kerala, during the monsoon months. Cercariae are of the virgulate xiphidiocercous type. Metacercariae occurred in the connective tissues, hepatopancreas and musculature of the freshwater crab, Paratelphusa hydrodromous. The growth and development of the metacercariae in P. hydrodromous have been studied in detail. Frogs became infected when they fed on infected crabs. The prepatent period is 10 days.

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Molecular Identification and Geometric Morphometric Analysis of Haematobosca aberrans (Diptera: Muscidae)

Insects ◽

10.3390/insects11070451 ◽

2020 ◽

Vol 11 (7) ◽

pp. 451 ◽

Cited By ~ 1

Author(s):

Tanasak Changbunjong ◽

Jiraporn Ruangsittichai ◽

Gerard Duvallet ◽

Adrian C. Pont

Keyword(s):

Sexual Dimorphism ◽

Geometric Morphometrics ◽

Morphometric Analysis ◽

Morphological Characters ◽

Wing Shape ◽

Coi Gene ◽

Morphological Identification ◽

Data Systems ◽

Geometric Morphometric ◽

Geometric Morphometric Analysis

The genus Haematobosca Bezzi, 1907 (Diptera: Muscidae) contains haematophagous flies of veterinary importance. A new fly species of this genus was recognised from northern Thailand based on morphological characters and described as Haematobosca aberrans Pont, Duvallet & Changbunjong, 2020. In the present study, the mitochondrial cytochrome c oxidase I (COI) gene was used to confirm the morphological identification of H. aberrans. In addition, landmark-based geometric morphometrics was used to determine sexual dimorphism. The molecular analysis was conducted with 10 COI sequences. The results showed that all sequences were 100% identical. The sequence was not highly similar to reference sequences from GenBank and did not match any identified species from Barcode of Life Data Systems (BOLD). Phylogenetic analysis clearly differentiated this species from other species within the subfamily Stomoxyinae. For geometric morphometric analysis, a total of 16 wing pictures were analysed using the landmark-based approach. The results showed significant differences in wing shape between males and females, with a cross-validated classification score of 100%. The allometric analysis showed that wing shape has no correlation with size. Therefore, the COI gene is effective in species identification of H. aberrans, and geometric morphometrics is also effective in determining sexual dimorphism.

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Geometric morphometrics for the study of hemicoxae sexual dimorphism in a local domestic equine breed

Journal of Morphological Sciences ◽

10.4322/jms.063513 ◽

2014 ◽

Vol 31 (04) ◽

pp. 214-218 ◽

Cited By ~ 1

Author(s):

P. Parés-Casanova

Keyword(s):

Sexual Dimorphism ◽

Morphometric Analysis ◽

Reliable Method ◽

Sex Differentiation ◽

Horse Breed ◽

Geometric Morphometric ◽

Photographic Images ◽

Average Accuracy ◽

Pelvic Shape ◽

Shape And Size

Abstract Introduction and material and methods. Twenty-height skeletonised hemicoxae from young animals (yearlings, 13 males and 15 females) belonging to the “CavallPirinencCatalà” horse (Catalan Pyrenean Horse) breed were studied by means of geometric morphometric (GM) methods. Morphometric analysis was based on coordinates of 16 landmarks of the ilium and ischiopubic regions that were digitised on 2D photographic images. Sexes did not appear separated either by size or shape, the latter being independent of the former.K-means clustering of shape variables were used in order to classify individuals by sex and an average accuracy of 57.1% was achieved. Results. Males were misclassified more frequently than females. For the iliac landmarks, which contributed to the total variance of shape with the higher degree, the value obtained increased to 60.7% for k-means. The ischiopubic complex contributed less to sex differentiation according to shape. Conclusion. It is concluded that the use of GM and multivariate statistics is not a reliable method to quantify pelvic shape and size differences between the sexes for equine yearlings. This is the irst known study to apply GM to the hip of an equine breed.

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

Journal of Applied Biomechanics ◽

10.1123/jab.2015-0271 ◽

2016 ◽

Vol 32 (5) ◽

pp. 441-448 ◽

Cited By ~ 1

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.

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