Journal
JOURNAL OF VETERINARY MEDICAL SCIENCE
Volume 64, Issue 2, Pages 137-144Publisher
JAPAN SOC VET SCI
DOI: 10.1292/jvms.64.137
Keywords
growth; individual variation; principal component analysis; sexual dimorphism; skull morphology
Categories
Ask authors/readers for more resources
Cranial features (development, individual variation, and sexual dimorphism) were examined from the 23 metrical characters and 2 nonmetrical characters (the degree of closure of the 9 cranial sutures and the presence of sagittal crest) in the two spotted seal specimen groups at the Nemuro Strait, Hokkaido. One Specimen group was incidentally taken in the salmon trap nets between 1982 and 1983 (n=70), and the other was randomly sampled by damage control kill between 1997 and 1998 (n=82). The development of morphometrical characters of skulls ceased at 5.6, 10.7, 7.9, and 11.9 yr. old, for 1982-83 male, 1982-83 female, 1997-98 male and 1997-98 female, respectively. The sutures were half ankylosed till approximately 10 yr. old in both sexes. The sagittal crest began from about 5 yr. old in male. Individual variation of skull was large in the feeding, breathing, and facial-expression apparatus. On the other hand, the variation of braincase, and skull concerning to the movement of head/neck tended to be small. Only 1997-98 specimens exhibited a sexual dimorphism in skull characters except for the braincase, whereas the dimorphism was not found in 1982-83 specimens. We could not detect the significant difference between two specimen groups, although there were a few differences in characters related to the rostrum and mandible.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available