The biggest fish might inspire awe and of course it should, but the largest animal (including fish) that ever lived is still around today. The blue whale, which also feeds on microscopic organisms (although I believe it eats krill rather than plankton) is endangered though, so it might not be around much longer. I hope it never goes extinct.
I wonder if this fish also had some kind of filter to get food out of the water, like the whale has baleen. It seems like it would be difficult to eat enough if it didn't.