[BiO BB] Fish genomics

[Nagesh Chakka]

Hi All,
I just started work with fish genomes for my comparative study. I am a 
bit puzzled as to why three different fish species were selected for 
sequencing (Danio rerio , Fugu rubripes, and Tetraodon nigroviridis). Is 
there is any advantage  in each of these species selected for sequencing 
which is not there in the other? I am addressing this question to this 
forum as I have a feeling that someone out there may be working with 
fish genome and may be having extensive information about what I was 
looking for. Please also note that I could not find any straight forward 
answer to my question searching the web.
Thanks
Nagesh