Do some specimens of F. flavissimus have a little longirostris mixed in, or is the snout length simply variable within the species itself? I have two flavissimus, and one definitely has a longer snout than the other, but is also definitely not F. longirostris.
Compare some of the FB pics:
http://www.fishbase.org/Photos/ThumbnailsSummary.php?ID=5584
Compare some of the FB pics:
http://www.fishbase.org/Photos/ThumbnailsSummary.php?ID=5584