Morphometric variation in the Hooded seal (Cystophora cristata)
Morphometric variation in the Hooded seal (Cystophora cristata)
复制标题
冠海豹（Cystophora cristata）的形态变化
DOI：
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发表时间：
2009
期刊：
影响因子：
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通讯作者：
Øystein Wlig
中科院分区：
文献类型：
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作者：
Øystein Wlig
对西北大西洋海域捕获的233只成年斑海豹的16个头骨尺寸和体长进行了性内和性间变异研究。绝对生长通过应用于一维的渐近生长曲线以及数学转换的颅骨数据的第一主成分评分来描述，这被认为反映了生长的多变量性质。所有尺寸被发现是完全发达的男性比女性晚。根据第一主成分的得分，发现男性头骨的生长持续了20多年，而女性比男性提前约-7年接近最终尺寸。雌性海豹在成熟时达到最终总体长的86%，这是一种广义的鳍足模式。在两种性别中，一岁的头骨的特点是一个大的脑案件，这与增长相对减少。男性头骨的进一步特点是增加颅宽和眶宽的基础长度，这是没有发现在女性。
男性的所有渐近值均显著大于女性。这种二型现象的形成主要是由于雄性在达到性成熟后的长时间生长。
Intra- and intersexual variation in 16 skull dimensions and total body length of 233 aged Hooded seals caught in the north-west Atlantic were investigated. Absolute growth was described by asymptotic growth curves applied to single dimensions, as well as to scores on the first principal component of logarithmically transformed cranial data, which are believed to reflect the multivariate nature of growth. All dimensions were found to be fully developed later in males than in females. The growth of the male skulls was found to continue for more than 20 years, while the females approach final size about–7 years earlier than males, according to the scores on the first principal component. Female seals were found to reach 86 % of final total body length at the time of maturation, which is a generalized pinniped pattern. In both sexes, a yearling skull was characterized by a large brain-case, which decreased relatively with growth. The male skulls were further characterized by an increase in zygomatic width and orbital width in relation to basal length, a pattern which was not found in females.
All the asymptotic values were significantly larger in males than in females. The dimorphism develops mainly as a result of prolonged growth of males after the attainment of sexual maturity.