In the Artscroll Stone chumash, there is a reference to R. Hirsch in 1:27 "although all living creatures were created male and female."
But this might indicate some combination within a single entity.
Rashi on 2:19 writes:
It also teaches you here that at the time of their forming, immediately on that day, He brought them to man to name them (Avoth d’Rabbi Nathan, ch. 1).
But what was brought immediately?
on 2:21 Rashi writes:
And the Lord God caused a deep sleep to fall: [Gen. Rabbah 17:4] When He brought them [the animals], He brought before him of every species, male and female.
If what was brought immediately was a male and a female, then what was created was a pair.
However, there is no reason to think that this means "only one pair".