The ontogenetic changes in the thermal properties of blubber from Atlantic bottlenose dolphin Tursiops truncatus
The ontogenetic changes in the thermal properties of blubber from Atlantic bottlenose dolphin Tursiops truncatus
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DOI：
10.1242/jeb.01559
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发表时间：
2005-04-01
影响因子：
2.8
通讯作者：
Pabst, DA
中科院分区：
文献类型：
--
作者：
Dunkin, RC;McLellan, WA;Pabst, DA
在大西洋短吻海豚Tursiops truncatus，无论是厚度和脂肪含量不同个体发育和不同的生殖和营养状况的个体。本研究探讨如何在鲸脂形态和组成的这些变化影响其热性能。热导率（W m（-1）deg（-1）deg“，其中deg.是摄氏度）和热绝缘（m（2）度。W-1）的海豚鲸脂的个体发育系列（胎儿到成人，N=36），怀孕的女性（N=4）和消瘦的动物（N=5）。这些热性能是通过同时使用两种常用的实验方法，热流圆盘法和标准材料法来确定的。测量每个鲸脂样品的厚度、脂质和水含量。导热性和绝缘性在个体发育过程中变化很大。胎儿到亚成体的鲸脂传导性（范围=0.11-0.13 +/- 0.02 W m（-1）deg（-1））低于成体（平均值=0.18 W m（-1）deg（-1））。怀孕雌性鲸脂的电导率与未成年类别相似，而瘦弱动物的电导率显著高于所有其他类别（0.24 +/- 0.04 W m deg（-1））。亚成体和怀孕雌性鲸脂的绝缘值最高，而胎儿和消瘦动物的绝缘值最低。在营养依赖的生活史类别，在鲸脂的隔热变化的特点是稳定的鲸脂质量（即导电性）和增加鲸脂量（即厚度）。在营养独立的动物，鲸脂数量保持稳定，而鲸脂质量变化。最后一个意想不到的观察结果是，在深鲸脂表面的热通量测量值显着高于表面，在控制材料中没有观察到的模式。这种明显的吸热能力，加上鲸脂的脂肪酸成分，表明海豚的外皮可能具有相变材料的功能。
In Atlantic bottlenose dolphins Tursiops truncatus, both the thickness and lipid content of blubber vary across ontogeny and across individuals of differing reproductive and nutritional status. This study investigates how these changes in blubber morphology and composition influence its thermal properties. Thermal conductivity (W m(-1) deg(-1)', where deg. is degrees C) and thermal insulation (m(2) deg. W-1) of dolphin blubber were measured in individuals across an ontogenetic series (fetus through adult, N=36), pregnant females (N=4) and emaciated animals (N=5). These thermal properties were determined by the simultaneous use of two common experimental approaches, the heat flux disc method and the standard material method. Thickness, lipid and water content were measured for each blubber sample. Thermal conductivity and insulation varied significantly across ontogeny. Blubber from fetuses through sub-adults was less conductive (range=0.11-0.13 +/- 0.02 W m(-1) deg(-1)) than that of adults (mean=0.18 W m(-1) deg(-1)). The conductivity of blubber from pregnant females was similar to non-adult categories, while that of emaciated animals was significantly higher (0.24 +/- 0.04 W m deg(-1)) than all other categories. Blubber from sub-adults and pregnant females had the highest insulation values while fetuses and emaciated animals had the lowest. In nutritionally dependant life history categories, changes in blubber's thermal insulation were characterized by stable blubber quality (i.e. conductivity) and increased blubber quantity (i.e. thickness). In nutritionally independent animals, blubber quantity remained stable while blubber quality varied. A final, unexpected observation was that heat flux measurements at the deep blubber surface were significantly higher than that at the superficial surface, a pattern not observed in control materials. This apparent ability to absorb heat, coupled with blubber's fatty acid composition, suggest that dolphin integument may function as a phase change material.