Type of confined aquifer containing groundwater under positive pressure.

A well, normally deep-drilled through impermeable material through which water is then rises via natural hydrostatic pressure.

A decapod gill associated with the articular membrane between the coxa of an appendage and the body.

Any member of the phylum Arthropoda, these being characterised by a (usually) chitinous exoskeleton and segmented body to which jointed appendages are attached in pairs. Arthropods include the insects, crustaceans, arachnids, myriapods, and extinct trilobites, and comprise the largest phylum in the animal kingdom.

A vertical process on the anterior part of the premaxillary bone in most teleosts.

Genus of isopod crustaceans in the family Asellidae. Contains the well-known ‘water louse’, Asellus aquaticus.

Mode of reproduction which does not involve fertilisation whereby offspring derive from a single parent and inherit genes only from that parent. Known in the Amazon Molly, Poecilia formosa, and some other fish species.

A collection of individuals or things.

Carotenoid pigment found naturally in some fishes, crustaceans, microalgae and yeasts. Known to improve conditioning/colouration and used in some fish foods.

The smaller of the two otoliths found in the inner ear of many fishes but the larger in members of the family Cyprinidae.

Tapering to a point; slender.

Not conforming to type; an abnormal specimen.

Latin term meaning ‘of authors’, often used to indicate that a name is being used in the (different) sense of a number of subsequent authors and not as established by the original author. Abbreviated to auct. or auctt.

Adopted German term meaning 'surface growth' used to describe the aggregate of plants, animals and detritus adhering to solid surfaces such as rocks or vegetation in aquatic environments.

Originating where found; indigenous to a particular environment or distributional range; native.

Automated device used to regulate feeding of prepared foods to fishes in the aquarium hobby and intensive aquaculture.

Automated system for adding water to an aquarium or sump in order to maintain a constant water volume. Particularly important in marine aquaria where salinity increases if water is allowed to evaporate without being replaced.

An organism capable of synthesising its own food via inorganic light or chemical energy, e.g., green plants, algae.

Small scales attached to the body of larger scales.

Located on, around, or in the direction of an axis running antero-posteriorly through the centre of a fish. Opposite of radial.