I'm probably of a different mindset, I've treated mine in a different manner-
Fish, dust to dust in a sense- they go to the garden or compost pile.
My past small pets have been buried here at home.
One cat I lost was left at the vet office for them to dispose of, the other went to a vet school upon his passing due to a slight deformity he had.
Some of my past dogs have been buried on my Grandparents property, one who was quite large was left at the vet office. Others I've had actually went away to the landfill as I worked in a setting that allowed for me to take them there with the consideration of my local legalities when it comes to toxic waste.
All, aside from the fish, have memorial stones or have perrenial plants , bushes or trees up in their memory but the physical bodies aren't a huge concern to me once the animal has passed.