Here's why:
* Species refers to a group of organisms that can reproduce and create fertile offspring. All domestic rabbits belong to the same species: *Oryctolagus cuniculus*.
* Breeds are variations within a species, developed through selective breeding. Many breeds have lop ears.
Some popular lop-eared rabbit breeds include:
* Dutch
* French Lop
* English Lop
* Mini Rex
* Holland Lop
* American Fuzzy Lop
* Harlequin
* Lionhead
So, while there are many lop-eared rabbit breeds, they are all variations within the same species: *Oryctolagus cuniculus*.