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

  • Pere M. Parés-Casanova (a1) and C. Allés (a1)

Summary

The 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.

L'existence de dimorphisme sexuel chez le cheval Minorquin, une race autochtone de l’Île de Minorque dans l'Archipel des Baléares (Nord-Ouest de la Mer Méditerranée), est reconnue dans le standard officiel, avec les femelles étant plus basses et longues que les mâles et ayant le cou plus fin et la croupe plus carrée. Cependant, aucune étude n'a, jusqu’à présent, examiné séparément les composants de taille et forme de ce dimorphisme. L'objectif de cette étude a été d'analyser la morphologie de cette race en utilisant des Méthodes de Morphométrie Géométrique (MMG) afin de déceler des différences de taille et forme entre les lignées d’étalons. L'analyse s'est basée sur des repères numérisés sur la vue latérale de 38 chevaux Minorquins adultes inscrits (20 mâles et 18 femelles), âgés de 3 à 14 ans (7 ans, en moyenne) et avec différents objectifs de performance. Pour les repères considérés, les analyses n'ont pas mis en évidence des différences significatives entre la forme et la taille des individus mâles et femelles, comme quoi les sexes sont similaires d'un point de vue fonctionnel.

La existencia de dimorfismo sexual en el caballo Menorquín, una raza autóctona de la Isla de Menorca en el Archipiélago Balear (Noroeste del Mar Mediterráneo), está recogida en el estándar oficial, siendo las hembras más bajas y largas que los machos y con un cuello más fino y una grupa más cuadrada. Sin embargo, hasta la fecha, ningún estudio ha explorado por separado los componentes de tamaño y forma de este dimorfismo. El objetivo de este estudio fue analizar la morfología de esta raza usando Métodos de Morfometría Geométrica (MMG) con el fin de dilucidar diferencias en tamaño y forma entre las líneas paternas. El análisis se basó en puntos de referencia digitalizados sobre la vista lateral de 38 caballos Menorquines adultos registrados (20 machos y 18 hembras), con edades comprendidas entre los 3 y los 14 años (7 años de media) y con diferentes fines productivos. Para los puntos de referencia estudiados, los análisis no arrojaron diferencias significativas entre la forma y el tamaño de los ejemplares machos y hembras, con lo que los sexos son similares desde un punto de vista funcional.

Copyright

Corresponding author

Correspondence to: P.M. Parés-Casanova, Department of Animal Production, University of Lleida, Av. Alcalde Rovira Roure 191, 25198-Lleida, Catalunya, Spain. email: peremiquelp@prodan.udl.cat

References

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Adams, D.C., Slice, D.E. & Rohlf, F.J. 2004. Geometric morphometrics: ten years of progress following the ‘revolution’. Italian Journal of Zoology, 71: 516.
Batista, L.F., Queiroz, F., Raquel, C., Cezar, P., Coelho, G., Mauro, E. & Corassa, A. 2008. Evaluation of the sexual dimorphism in Mangalarga Marchador horses using discriminant analysis. Livestock Science, 119(1–3): 161168.
Bookstein, F.L. 1991. Morphometric Tools for Landmark Data: Geometry and Biology. Cambridge, Cambridge University Press.
Cervantes, I., Baumung, R., Molina, A., Druml, T., Gutiérrez, J.P., Sölkner, J. & Valera, M. 2009. Size and shape analysis of morphofunctional traits in the Spanish Arab horse. Livestock Science, 125: 4349.
Dryden, I.L. & Mardia, K.V. 1993. Multivariate shape analysis. Sankhya, 55(A): 460480.
Franklin, D., Cardini, A., O'Higgins, P., Oxnard, C.E. & Dadour, I. 2008. Mandibular morphology as an indicator of human subadult age: geometric morphometric approaches. Forensic Science, Medicine and Pathology, 4: 9199.
Gower, J.C. 1975. Generalized procrustes analysis. Psychometrika, 40: 3355.
Hammer, Ø., Harper, D.A.T. & Ryan, P.D. 2001. PAST: paleontological statistics software package for education and data analysis. Paleontologia Electronica, 4(1). [online]. URL: http://palaeo-electronica.org/2001_1/past/issue1_01.html (accessed on April 23rd 2013).
Hevia, M.L. & Quiles, A. 1993. Determination of sexual dimorphism in thoroughbred based on exterior measurements. Archivos de Zootecnia, 42: 451456.
Jungers, W., Falsetti, A. & Wall, C. 1995. Shape, relative size, and size-adjustments in morphometrics. Yearbook of Physical Anthropology, 38: 137161.
Klingenberg, C.P. 2011. MorphoJ: an integrated software package for geometric morphometrics. Molecular Ecology Resources, 11: 353357.
Olsen, S.L. 2003. Horses Through Time. Pittsburg, Carnegie Museum of Natural History.
Purzyc, H., Kobrynczuk, F. & Bojarski, J. 2011. Sexual dimorphism in Hucul horses using discriminant analysis. Animal, 5(4): 506511.
Rohlf, F.J. 2003. tps Small version 1.20. Department of Ecology and Evolution, State University of New York, Stony Brook, New York.
Rohlf, F.J. 2010. tps Dig version 2.16. Department of Ecology and Evolution, State University of New York, Stony Brook, New York.
Rohlf, F.J. & Slice, D.E. 1990. Extensions of the Procrustes method for the optimal superimposition of landmarks. Systmatic Zoology, 39: 4059.
Sheets, H.D. 2003. IMP-integrated Morphometrics Package. Buffalo, New York, Department of Physics, Canisius College.
Slice, D.E. 2001. Landmark coordinates aligned by Procrustes analysis do not lie in Kendall's shape space. Systematic Biology, 50: 141149.
Van Damme, R., Entin, P., Vanhooydonck, B. & Herrel, A. 2008. Causes of sexual dimorphism in performance traits: a comparative approach. Evolutionary Ecology Research, 10: 229250.

Keywords

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

  • Pere M. Parés-Casanova (a1) and C. Allés (a1)

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