Prefix meaning 'new'.

Form of paedomorphism characterised by retention of juvenile features in an adult individual via slowed or delayed maturation.

Of or relating to a zoogeographical region consisting of South America plus the portion of North America lying south of the tropic of Cancer.

A single specimen designated as the name-bearing type of a species subsequent to its description, most often when the holotype, lectotype, and syntype no longer exist.

In cladistics, used to refer to a clade located within a larger clade.

A bony or cartilaginous arch-shaped structure arising from the dorsal side of a vertebra and enclosing the spinal cord.

The section of the skull housing and protecting the brain.

Individual sense organ of the lateral line system, comprising nerve fibres connected to a cluster of sensory cells.

Severe physical condition of unconfirmed origin occurring in certain fishes which appears related to poor water quality and/or nutrition. The primary symptom is necrosis of the tissue surrounding neuromasts on both the head and body and if left unchecked the disorder can result in death. Similar to, but not analagous with, head and lateral line […]

A toxin affecting the nervous system.

Neither acidic nor alkaline.

Pure, ion-free water with a pH of or very close to 7.0.

In zoological nomenclature, the first combination of a generic and previously-published specific name.

The position or role occupied by an organism within an ecological community.

An overlap in resource requirements by two or more species.

See nitrate reactor.

Piece of aquarium equipment that can be thought of as an anaerobic filter. Provides a means by which large enough populations of anaerobic bacteria can be maintained so that nitrates are actively removed from the water in the form of nitrogen gas, a process normally facilitated by regular partial water changes. Also known as a […]

Any salt or ester of nitric acid, and the end product of the portion of the nitrogen cycle taking place in most closed aquarium systems (the conversion of nitrates to nitrogen gas in natural systems is carried out by anaerobic microorganisms not normally present in sufficient numbers in aquaria, though this process can be induced […]

To convert ammonia or other nitrogen compounds into nitrites or nitrates.

A salt or ester of nitrous acid. Produced in aquaria via metabolisation of ammonia by nitrifying bacteria of the genus Nitrosomonas, and toxic to fishes if present in sufficient concentrations, but in a mature system is further converted into less-harmful nitrates by other bacteria of the genus Nitrospira.