Glossary

fertile

Used in 11 species profiles

annual fish
A fish species which naturally completes its life cycle within a year at the end of which it dies leaving behind fertile eggs which typically survive in the soil and hatch during the next rainy season. Often used in reference to certain South American and African killifishes.
biological species concept
Most popular concept of species in vertebrate zoology. Defines species as members of populations that do or potentially could interbreed and produce fertile offspring in nature, regardless of appearance, therefore somewhat more restrictive than the phylogenetic species concept. In theory species are thus separated from one another by some form of reproductive isolation, though in practice this does not always hold true. Often abbreviated to BSC.
fertility
The state of being fertile.
reproduction
Production of offspring via a sexual or asexual process.
sibling species
One of two or more very closely-related species that are reproductively isolated from one another but almost indistinguishable in morphologically and/or behaviourally. May occur sympatrically and even interbreed but are incapable of producing fertile hybrid offspring. Sometimes referred to as cryptic species.
subspecies
Taxonomic rank below species, written in the form of a trinomen. Often applied to a geographically-separated population within a species that retains the capability to produce fertile offspring with other populations but may exhibit phenotypic differences.