An interesting science story that goes to show what we know is not always right. How long has it been said and assumed that sharks and fish are cold-blooded? That the temperature of their blood is equal to that of the ocean in which they swim? Turns out that for some fish and sharks, that may not be the case after all. This article in the National Science Foundation magazine says that new research shows that Lamnid sharks elevate their temperature in the red muscle near the backbone in order to stay alive in cold water. The evidence applies to lamnids (which also includes Makos and Great Whites) as they were the focus of the study, so it does not apply to all fish, but it is interesting none the less because we are all taught that sharks don’t ever stop swimming, and this is one of the reasons for this type of shark in cold water. Certain Sharks Not so Cold-Blooded?
An interesting science story that goes to show what we know is not always right. How long has it been said and assumed that sharks and fish are cold-blooded? That the temperature of their blood is equal to that of the ocean in which they swim? Turns out that for some fish and sharks, that may not be the case after all. This article in the National Science Foundation magazine says that new research shows that Lamnid sharks elevate their temperature in the red muscle near the backbone in order to stay alive in cold water. The evidence applies to lamnids (which also includes Makos and Great Whites) as they were the focus of the study, so it does not apply to all fish, but it is interesting none the less because we are all taught that sharks don’t ever stop swimming, and this is one of the reasons for this type of shark in cold water. 
1. speaking of sharks, anyone ever tried shark meat? It's actually pretty good (not all kinds though).
Posted at 2:03AM on Nov 9th 2005 by Hani