noun
related species; allied species
Biological term for a species closely related to another, often used in taxonomy, ecology, and evolutionary biology.
この植物の近縁種は南米に分布している。
A related species of this plant is distributed in South America.
絶滅危惧種とその近縁種の遺伝子を比較する。
Compare the genes of the endangered species and its allied species.
類縁 is a broader term for 'affinity' or 'kinship', not limited to species; 近縁種 specifically refers to a closely related species.
Compound of 近 (close) + 縁 (relation) + 種 (species). A straightforward modern technical term.