It was Forge World (FW) not Fantasy Flight (FFG) who changed the name to Charachadons (or whatever). Now, I may have been misinformed, but I am sure they published something about the Space Sharks firing water filled boarding torpedoes at enemy ships, partially flooding the interior so that defenders would be impeded. The Space Sharks, being trained for fighting in these conditions, therefore had the upper hand.
Space Sharks riding flying sharks, on the other hand, was just an awesome parody a few people have done of the idiocy that was Space Wolves riding actual wolves.
I will accept I may have been misinformed, or it may be the case that element of the background has been quietly filed away somewhere.