Submitted by Anonymous on Mon, 11/12/2012 - 04:06
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Weddell Seals in the Ross Sea

What are the composition differences between blubber and the fat that the rest of us carry about?

Thu, 11/15/2012 - 07:12

Alex Eilers

I am waiting on a reply from the team. Will post answer soon.

Thu, 11/15/2012 - 13:01

Alex Eilers

Here's a message from Dr. Burns...Both seal blubber and our fat are made up of similar components - adipocytes are the cells that contain the lipid (fat) and a collagen fiber matrix that provides structure to the tissue (like a scaffolding). However, seal blubber has more structure to it than our fat (it's less squishy) so that it can also act in its role in streamlining and hydrodynamics. Blubber is ~ 85% lipid and ~ 15% structural elements. I am not sure what the human breakdown is. In addition, the types and amounts of lipid that are stored in the tissues likely differ slightly - blubber lipids closely resemble the lipids in the seal's diet, so they are very 'fishy', whereas ours contain a mix of dietary and biosynthesized lipids (and unless you only eat fish must differ).
Best - Alex

Thu, 11/15/2012 - 14:05

Alex Eilers

And Linnea has also chimed in...The main difference between the blubber and fat is the amount of collagen in it. Collagen is a structural protein that gives thing shape (you hear about it in skin care a lot...). The collagen in seal blubber helps keep the blubber firm and dense, rather than mushy, which is important because the blubber needs to streamline the body of the seal, so they can be more efficient swimmers. Seals are also unique in that all the fat in their bodies is stored in the blubber layer, where as most mammals, including us, have 12 different places we deposit fat throughout our bodies.
Best - Alex