Skull morphometrics of adult male Antartic fur seal, Arctocephalus gazella, and South American fur seal A. australis Morfometría craneana comparada de ejemplares machos adultos de lobo fino antártico, Arctocephalus gazella y lobo fino sudamericano, A. australis

• Published in: Iheringia. Série Zoologia
• Main Authors: Gustavo A. Daneri, César M. García Esponda, Luciano J. M. De Santis, Laura Pla
• Format: Article in Journal/Newspaper
• Language: English; Spanish; Portuguese
• Published: Fundação Zoobotânica do Rio Grande do Sul 2005
• Subjects: Arctocephalus; Otariidae; características craneanas; cranial characteristics; Zoology; QL1-991; Alta; Antarctic; Antarc*; Antarctic Fur Seal; antartic*; Arctocephalus gazella
• Online Access: https://doi.org/10.1590/S0073-47212005000300006; https://doaj.org/article/f45364038efd464391bfc49f0baa24f3

The skull morphometrics of adult male Antarctic fur seal, Arctocephalus gazella (Peters, 1875) and South American fur seal, A. australis (Zimmermann, 1783) were investigated using a collection of 45 and 38 skulls, respectively. Eighteen measurements were taken for each specimen. Comparative univariate and multivariate statistical analyses included standard statistics, one-way analysis of variance, principal component analysis and discriminant analysis. Individual variation was relatively high for some variables, as expressed by the coefficient of variation. Skulls of A. gazella were larger than those of A. australis for all but two variables: squamosal jugal suture and rostral length. Both species differed significantly as shown by both univariate and multivariate analyses. The discriminant function correctly classified all specimens. The standardized canonical coefficients showed that the variables which most contribute to the differentiation between species were, in decreasing order, the rostral length, palatal length, palatal width at postcanine 5 and braincase width. The present study corroborates that A. gazella and A. australis are phenotipically distinct species. Se estudió la morfometría craneana de especímenes machos adultos de lobo fino Antártico, Arctocephalus gazella (Peters, 1875) y lobo fino sudamericano, A. australis (Zimmermann, 1783), consultando una colección de 45 y 38 cráneos respectivamente. Para cada ejemplar se tomó un total de 18 medidas. El análisis comparativo univariado y multivariado incluyó estadística standard, análisis de varianza, análisis de componentes principales y análisis discriminante. La variación individual, según lo expresado por el coeficiente de variación, fue relativamente alta para algunas variables. Los cráneos de A. gazella fueron proporcionalmente más grandes que aquellos de A. australis para todas las variables estudiadas, excepto dos: longitud de la sutura escamoso-yugal y longitud rostral. Tanto el análisis uni como mutivariado indicaron que ambas especies ...