Subspecies

Taxonomic rank subordinate to species

Subspecies

A subspecies is a taxonomic rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics (morphology), but that can successfully interbreed. Not all species have subspecies, but for those that do there must be at least two. Subspecies is abbreviated as subsp.

From Wikipedia, under CC BY-SA. More on occurri.