A lot of those were single-fish tanks. My bettas were single fishes and i had dozens of those. My killifish was also single. I had my south american cichlid tanks, my guppy tanks, my goldfish tanks and some mixed tropical tanks. My isolation tanks were single tanks that ebbed and flowed with quarantined fishies.
I miss my guppies - I was breeding a very interesting variety and i loved the constant babies. And I miss my goldfish tank, which had freshwater clams and apple snails in it. Those were awesome.
I know better than to have fish now. My life is not stable enough. And there is no room in the RV.
The two cats and one dog is probably as much as I should have, but i would like to have a large dog. And another kitten to replace William.
I have to be really careful not to add more pets to my little brand of crazy. Maybe if the Oklahoma thing happens I can have the large dog and some more cats. Plus chickens! And maybe two fish tanks...