buffalofish vs buffalo fish

buffalofish and buffalo fish both are nouns.

Word	Noun	Adjective	Verb	Adverb
buffalofish	Yes	No	No	No
buffalo fish	Yes	No	No	No

As nouns, buffalofish and buffalo fish are synonyms defined as:

buffalofish and buffalo fish: any of several large suckers of the Mississippi valley

buffalofish (noun)	buffalo fish (noun)
any of several large suckers of the Mississippi valley	any of several large suckers of the Mississippi valley
large carp-like North American fish