Baleen is a resilient and keratinised filter-feeding structure attached to the maxilla of mysticete whales. It is strong and tough, yet a pliant and resilient material, that withstands extreme pressures in the oral cavity during feeding. We investigated the structure, water content, wettability and mechanical properties of baleen of the Southern right (SRW) and Pygmy right whales (PRW), to understand the effects of hydration on the physical and mechanical properties of baleen. Sixty 25 × 15mm baleen subsamples were prepared from one individual of SRW and PRW. Half were hydrated in circulated natural seawater for 21 days and half were dry. Water content analysis showed that SRW baleen was 21.2% water weight and PRW was 26.1%. Wettability testing indicated that surfaces of both hydrated and dried SRW and PRW baleen were hydrophilic, with hydrated samples of both species having lower contact angle values. For the SRW, the average contact angle of hydrated baleen was 40° ± 13.2 and 73° ± 6 for dried samples. Hydrated PRW baleen had an average contact angle of 44° ± 15.3, which was lower than in dried samples (74° ± 2.9). Three-point bending mechanical tests showed that the average maximum flexural stress of dried SRW (134.1 ± 34.3 MPa) and PRW samples (117.8 ± 22.3 MPa) were significantly higher than those of hydrated SRW (25.7 ± 6.3 MPa) and PRW (19.7 ± 4.8 MPa) baleen. Scanning electron microscope images showed the stratification of the outer cortical layer, with cross-linked keratin fibres observed within and between baleen keratin sheets. Hydrated baleen, as in its natural and functional behaviour, has greater flexibility and strength, attributes necessary for the complex filter feeding mechanism characteristic of whales. Hydration must be considered when addressing the physical and mechanical properties of baleen, especially when using dried museum specimens.

Baleen是一种有弹性且角质化的滤嘴喂养结构，附着在神秘鲸的上颌骨上。它既坚固又坚韧，又是一种柔韧而有回弹力的材料，可以在喂养期间承受口腔中的极高压力。我们研究了南部权利（SRW）和P格米人鲸（PRW）的巴里恩的结构，含水量，润湿性和机械性能，以了解水合对巴里安的物理和机械性能的影响。从一个SRW和PRW个体中制备了60个25×15mm的baleen子样品。一半在循环的天然海水中水合21天，另一半干燥。含水量分析表明，SRW baleen的水分含量为21.2％，PRW为26.1％。润湿性测试表明，水合和干燥的SRW和PRW baleen的表面均具有亲水性，两种水合样品的接触角均较低。对于SRW，对于干燥的样品，水合的baleen的平均接触角为40°±13.2和73°±6。水合PRW baleen的平均接触角为44°±15.3，低于干燥样品的平均接触角（74°±2.9）。三点弯曲力学测试表明，干燥的SRW（134.1±34.3 MPa）和PRW样品（117.8±22.3 MPa）的平均最大弯曲应力显着高于水合SRW（25.7±6.3 MPa）和PRW（19.7± 4.8 MPa）Baleen。扫描电子显微镜图像显示外皮质层分层，在角蛋白片内部和之间观察到交联的角蛋白纤维。与天然和功能性行为一样，水合的baleen具有更大的柔韧性和强度，鲸的复杂过滤器进食机制特性必需的属性。在处理香脂的物理和机械性能时，尤其是在使用干燥的博物馆标本时，必须考虑水合。