MSC 350 Lecture Notes - Lecture 12: Life History Theory, Earless Seal, Embryonic Diapause
25 Oct 2016
School
Department
Course
Professor
Document Summary
Life history and reproduction: life history theory. Why animals behave the way they do over a lifetime. Reproduction = key component of fitness: marine mammals. Long lived, slow growth, delay sexual maturity, produce. General characteristics few offspring but invest in them heavily: number of offspring. Typically 1 to increase chances of survival. Twinning in some offspring but very rare: gestation. Mysticetes have the highest rate of fetal growth in animal kingdom. Pinnipeds and sea otters can perform embryonic diapause to preferentially become pregnant during ideal situations: precociality. Phocids are born with natal coat and blubber; the longer lactating phocids are born with more coat. Harbor and hooded seals shed the natal coat in utero but are born larger: sexual maturity. Defined by ability to fertilize or become fertilized. Delayed in all marine mammals due to the importance of reaching a large size. Usually first few calves do not survive. Toxins built up in mother"s body will come out in milk.
