Developmental changes in bone mechanics from Florida manatees (Trichechus manatus latirostris), obligate swimming mammals.

摘要: Mammals living in aquatic environments load their axial skeletons differently from terrestrial counterparts. The structure and mechanical behavior of trabecular bone can be especially indicative varying habitual forces. Here, we investigated vertebral properties (yield strength, stiffness toughness) throughout development Florida manatees (Trichechus manatus latirostris), obligate undulatory swimmers. Thoracic, lumbar caudal vertebrae were dissected (N=20) during necropsies. We extracted 6 mm3 samples bodies tested them compression three orientations (rostrocaudal, dorsoventral mediolateral) at 2 mm min-1 determined variation between sexes, among developmental stages, regions testing orientations. also the relationships process lengths dorsoventrally mediolaterally bone. Rostrocaudally was strongest, stiffest toughest, suggesting that this is principal direction stress. Our results showed female subadults stronger stiffer than male counterparts; based on these data, hypothesize hormonal shifts sexual maturity may partially drive differences. In calves, posterior region tougher anterior region. as animals grow rapidly early development, would most ossified to support rostrocaudal force propagation associated with swimming.