In biological taxonomy, race is an informal rank in the taxonomic hierarchy for which various definitions exist. Sometimes it is used to denote a level below that of subspecies, while at other times it is used as a synonym for subspecies. It has been used as a higher rank than strain, with several strains making up one race. Races may be genetically distinct populations of individuals within the same species, or they may be defined in other ways, e.g. geographically, or physiologically. Genetic isolation between races is not complete, but genetic differences may have accumulated that are not (yet) sufficient to separate species.
Four different ecotypes, i.e. ecological races, of the species Physcomitrella patens, stored at the International Moss Stock Center
In biological classification, subspecies is a 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 subsp. or ssp. and the singular and plural forms are the same.
Ceylon paradise flycatcher (Terpsiphone paradisi ceylonensis), an Indian paradise flycatcher subspecies native to Sri Lanka
African leopard (Panthera pardus pardus), the nominotypical (nominate) leopard subspecies native to Africa
Sunda Island tiger (P. tigris sondaica), a tiger subspecies native to the Sunda islands
The Indian rhinoceros (Rhinoceros unicornis) is a monotypic species.
