Published online by Cambridge University Press: 16 October 2009
The results of detailed sterol analyses on the livers of seven species of sharks are presented. The sharks appear to have a very specific requirement for cholesterol as their sole component sterol (> 99 % total sterols), which several species of bony fish do not. In fact, from their sterol composition, sharks appear more similar to terrestrial vertebrate classes than bony fish. If, as has been suggested, sterol composition is a measure of evolutionary advancement, then this work presents biochemical evidence that sharks are not as primitive as has sometimes been assumed.