Yes, ARCHERFISH is a Scrabble word!

Letter values in Scrabble US: A 1, R 1, C 3, H 4, E 1, R 1, F 4, I 1, S 1, H 4.

Is it a valid word?

ARCHERFISH is a valid word in the official Scrabble dictionary (US), the UK Scrabble Dictionary and Words with Friends (ENABLE).

any of several small freshwater fishes that catch insects by squirting water at them and knocking them into the water; found in Indonesia and Australia

Also: toxotes jaculatrix.