Caspian Tern was created in 1770.
Sterna caspia
Not really. They primarily eat fish.
This is a Tern. Three match your description but since you talk of a black plume, it is the Elegant Tern. Two others are similar- Royal and one other.
small fish
yes because they eat fish
nickolas horidiski
the same as other horses
bread guppies and weeds
the same as other horses
They eat mainly fish and small marine invertebrates. - Wikipedia 17/10/09 [Aust]
We need location, size and behavior to be sure, but it is probably some sort of tern, possibly a Royal or Caspian.