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GEOGRAPHIC VARIATION IN SKULL MORPHOLOGY OF ADULT STELLER SEA LIONS ( EUMETOPIAS JUBATUS )
Author(s) -
Brunner Sylvia
Publication year - 2002
Publication title -
marine mammal science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.723
H-Index - 78
eISSN - 1748-7692
pISSN - 0824-0469
DOI - 10.1111/j.1748-7692.2002.tb01029.x
Subject(s) - skull , sexual dimorphism , biology , discriminant function analysis , zoology , intraspecific competition , morphometrics , geographic variation , sea lion , anatomy , geography , ecology , demography , population , machine learning , sociology , computer science
A bstract Data from cranial specimens of adult E. jubatus were analyzed to compare intraspecific morphology of skulls. Males and females were grouped separately to avoid bias from sexual dimorphism. Geographic variation was observed in adult male E. jubutus , indicating the potential presence of three morphologically disparate groups: those from Alaska, those from California, and those from Japan and Russia. Although sample sizes were small, results from cluster and discriminant function analyses indicated that specimens from eastern and western Alaska were morphologically similar, and that the most divergent specimens for the species appeared to be those from Japan. Skulls from Alaska possessed a typically longer, less robust skull, whereas those from Japan appeared smaller, yet most robust. Skulls from California were intermediate.