Taxonomy
G
Genus
/ /ˈdʒiːnəs/ /
Etymology:
From Latin genus — "birth, race, kind"
Quick Definition
A taxonomic rank above species and below family, grouping closely related species that share common ancestry.
📖 Full Definition
A genus (plural: genera) is the taxonomic level between family and species. In binomial nomenclature, the genus name is always capitalised and forms the first element of a scientific name. All members of a genus share a common ancestor and a set of homologous characters. Genus boundaries are set by taxonomists based on morphological, behavioural, and increasingly molecular data. Genera may contain one species (monotypic) or hundreds. The largest fish genera include Eviota (~100 species of tiny reef gobies) and Notropis (~130 species of shiners).
💡 Examples & Context
The genus Thunnus contains 8 species of true tunas, all sharing the same body plan but differing in size, physiology, and distribution.