Raised, epidermal structures developing on the head, body or fin rays during the spawning season in some fishes. Usually occur only in males, and sometimes referred to as 'nuptial tubercules'.

Water containing high amounts of a salt or salts.

See Artemia.

A fish which releases its gametes into open water for external fertilisation, with no subsequent parental care. The strategy is more commonly-seen in marine than freshwater species.

Offspring of fishes, especially a single group hatching together and/or being cared for by the same parent(s); the act of tending and protecting eggs or offsping.

The tending, caring for, and protection of a brood by one or both parents.

A group of sexually mature fish maintained specifically for production of fry.

A small, fast-flowing, normally first-order stream. Often emerge from springs.

Vernacular term commonly used in zoology when referring to the largely marine class Phaeophyceae which includes many seaweeds, and in the aquarium hobby to describe growths of brown, diatomic algae.

The plant phylum comprising mosses and liverworts. Members have no true roots, stem or leaves.

Aggregation of air-filled bubbles blown via use of an oral secretion constructed by males in some fish species. Such nests usually float and sometimes contain pieces of plant material for improved solidity. Fertilised eggs are deposited and incubated inside the nest and typically guarded by the male.

Of or relating to the mouth.

Cavity located inside the mouth, above the gill arches. Also referred to as 'mouth cavity'.

A substance that reduces change in the acidity of a solution when an acid or base is added.

See alkalinity.

The tendency or capacity to rise, float or sink in water.

Species other than the target caught incidentally when fishing with a net. Sometimes used when referring to aberrant specimens exported among shipments of wild-collected ornamental fishes.