A species occurring outside its known natural range, most often due to accidental or intentional dispersal by human activities. Also referred to as introduced or alien species.
Glossary: exotic species
Not extinct; surviving; still in existence.
Glossary: external filter
A filter located outside the aquarium, typically holding larger amounts of media than an internal filter and used for larger tanks. Also known as a canister filter.
Of a species or other taxonomic grouping, having no living members; no longer in existence.
The state of being or becoming extinct.
To destroy completely; to exterminate. Sometimes applied to cases where a species is extinct in one country or area but extant in others.
Glossary: eye diameter
In ichthyology, the greatest distance between the margins of the eye.
Glossary: eye spot
Glossary: eyed egg
A fish egg within which the embryo has developed to a point whereby the eyes are visible through the external membrane.
Term used in the aquarium hobby in reference to an eyed egg.