We happen to be working on a fish genome,
There is quite a good review on the evolutionary genetics of Fish which should
provide some pointers to the information you request:
The Evolutionary Genetics of Fish
Adv. in Genetics 1991, 29 : 119-228
Also the phylogeny is kept on the ncbi.nlm.nih.gov server,
available in the directory /repository by anon ftp.