At least 3 (possibly up to 10) different species of visible fish will be in the next Mo'Creatures update, hopefully sometime this week. For you haters, just disable everything but the fish.
You can already get a decent dragon mod that is still a work in progress, soon to be updated to have more kinds of dragons.
Wolves and dogs will be added sometime within the next two weeks.
Whales... I have no clue.
So basically, in a month AT MOST, you can get most of those mobs.