Why do Great White Sharks always have a big bloody gape?

Something has been bothering me the last while. I can’t figure out why Great White Sharks are always depicted as having a big bloody gape? I have researched it a bit but have not come up with any good information. As it I see it though, there are three distinct possibilities:

1. The big bloody gape is a fallacy propagated by Hollywood
2. Blood is leftover from a kill
3. The blood is their own

There are few points to be noted about each possibility:

1. Purusing some stock photography (seen below) it seems that there a a mix of shark pictures, with and without bloody mouths. And of course, this may be subject to a photographer’s bias.

2. If the blood is indeed from a kill, why would it stain so long and not simply wash away? Also, it should be noted that Great Whites don't eat that often.

3. If the blood is their own, why doesn’t it attract other sharks?

If you have comments on this topic, please let me know, I would like to solve this mystery!

Friday's Mystery Fossil

HINT: The feature running across the top of the picture will tell you what kind of (vertebrate) animal it is and the feature in the bottom right hand corner will narrow down the group.

Tough one! Any guesses?

Friday's Mystery Fossil Revealed

Congratulations to Mambo Bob for his response. Friday's Mystery Fossil was indeed a theropod and specifically a Tyrannosaurus but not Sue of the Chicago Field Museum. Rather, the picture is of a specimen at Palais de la découverte in Paris. Also, points Malacoda for his imaginative guess (an obvious asset in palaeontology:)

The image may be familiar to some as it was featured in my January posting, CSI: Garfield County.

Image copyright ©2005 David Monniaux.

Friday's Mystery Fossil:

HINT: Because this photo isn't at a high enough resolution, you cannot see the fine serrations on edges of the individual elements.

Come on, this one isn't too hard. Any guesses?