User:Kmerren/Hooded seal

Early development[edit]
Researchers find that due to a pup's differing needs in regards to sustaining work and foraging while under water compared to adults, the skeletal and cardiac muscles develop differently. Studies show that cardiac blood flow provides sufficient oxygen to sustain lipolytic pathways during dives, remedying their hypoxic challenge. Cardiac tissue is more developed than skeletal muscles at birth and during the weaning period, although neither tissue is fully developed by the end of the weaning period. Pups are born with fully developed hemoglobin stores (found in blood), but their myoglobin levels (found in skeletal tissue) are only 25–30% of adult levels. These observations demonstrate that pup muscles are less able to sustain either aerobic or anaerobic ATP production during dives than adults. This is due to the large stores of oxygen, either bound to hemoglobin or myoglobin, which the seals rely on to dive for extended periods of time. This could be a potential explanation for pups’ short weaning period as diving is essential to their living and survival.

New text:
Hooded seals shed their lanugo fur in the womb and are born with a thin non lanugo fur coat which is a less efficient thermoregulating fur coat compared to some to other seal species (e.g., leopard seals). Studies have shown that newborn hooded seals undergo a stage after birth where the thickness of their blubber grows rapidly, which maximizes their ability to thermoregulate and compensate for their thin fur coat. This process of fur removal in the womb and alternatively using blubber, may be advantageous because water cannot penetrate blubber like it does with fur, therefore blubber can insulate the seals in both water and air firmly uniformly.