There are no new fish in February - they're staying in warmer waters!
All Animal Crossing sea creatures arriving in February:
Like with the fish, there aren't any new sea creatures in February.
Animal Crossing bugs, fish and sea creatures leaving in February
Every month in New Horizons causes a number of creatures to leave your island. If you don't catch a creature before it vanishes, you might have to wait a number of months till it returns to your land.
We recommend searching out and catching any departing creatures at the beginning of the month to avoid any pressure in its final days.