A species is a distinct group of animals or plants that have common characteristics and can breed with each other. Your poodle and your bulldog are the same species, but your hamster and your goldfish are not.

All members of the same species have similar genes and can interbreed and produce offspring. A subspecies is a division of a species, and a genus includes several different species. Biologists use these categories to classify organisms, usually with Latin names like Canis familiaris, or "domestic dog." In Middle English, species meant "a classification in logic," borrowed from the Latin word meaning "kind or appearance," from the root of specere, "to see."

Definitions of species
  1. noun
    (biology) taxonomic group whose members can interbreed
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    bacteria species
    a species of bacteria
    endangered species
    a species whose numbers are so small that the species is at risk of extinction
    fish species
    a species of fish
    type species
    (biology) the species that best exemplifies the essential characteristics of the genus to which it belongs
    H. pylori, Heliobacter pylori
    the type species of genus Heliobacter; produces urease and is associated with several gastroduodenal diseases (including gastritis and gastric ulcers and duodenal ulcers and other peptic ulcers)
    Pseudomonas pyocanea
    a species of aerobic bacteria
    Aerobacter aerogenes
    a species of Gram-negative aerobic bacteria that produce gas and acid from sugars and are sometimes involved in the souring of milk
    Agrobacterium tumefaciens
    the bacteria that produce crown gall disease in plants
    Calymmatobacterium granulomatis
    the species of bacteria that causes granuloma inguinale
    Francisella tularensis
    the type species of the genus Francisella and the causal agent of tularemia in humans; can be used as a bioweapon
    Serratia marcescens
    the type species of the genus Serratia; a species found in water and soil and milk and foods and insects; can cause infections of the endocardium and blood and wounds and urinary tract and respiratory tract; has been tested as a bioweapon
    Streptococcus anhemolyticus
    a species of bacteria
    Australian lungfish, Neoceratodus forsteri, Queensland lungfish
    an endangered species of lungfish found in rivers in Queensland
    Australian arowana, Dawson River salmon, Scleropages leichardti, saratoga, spotted barramundi, spotted bonytongue
    a species of large fish found in Australian rivers
    Australian bonytongue, Scleropages jardinii, northern barramundi
    a species of large fish found in Australian rivers
    Asian seabass, Lates calcarifer, barramundi, giant perch, giant seaperch, white seabass
    a species of large perch noted for its sporting and eating qualities; lives in marine, estuary, and freshwater habitats
    type of:
    taxon, taxonomic category, taxonomic group
    animal or plant group having natural relations
  2. noun
    a specific kind of something
    “a species of molecule”
    “a species of villainy”
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    type of:
    form, kind, sort, variety
    a category of things distinguished by some common characteristic or quality
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