The IGV oyster genome uses 'oyster.v9.fa.'  Either copy it into this directory,
or use 'wget' from the command line to download the file:

wget http://eagle.fish.washington.edu/cnidarian/oyster.v9.fa&ei=Z7lBUr7MGKeYigKVy4HgBg&sa=X&oi=unauthorizedredirect&ct=targetlink&ust=1380040815405285&usg=AFQjCNGtJj_hBevKJDX0urxw4TOsf6jQWQ