Combining capacity of an atom or ion determined by the number of electrons that it will lose, add, or share when it reacts with other atoms; the bond-forming capacity of a given atom or radical; a numeric value designated to represent this capacity.

The correct, currently-accepted scientific name for a taxon.

A form or version that differs in some respect from other forms of the same thing or deviates from a standard.

Exhibiting differently coloured markings; diversified.

Type of seasonally-inundated floodplain forest in the Amazon region. The term is normally used for those forests flooded by whitewater rivers but is sometimes used to refer to blackwater environments for which the more traditional term is igapó.

Containing vessels that carry or circulate fluids, especially blood.

Of, relating to, or capable of growth, or functioning in processes such as growth or nutrition rather than sexual reproduction.

See ‘Oodinium‘.

Poisonous fluid secreted by various animals, including some fishes.

Secreting venom; able to inflict a poisonous bite, sting or wound.

Excretory opening of the digestive tract in fishes.

Of, on, or relating to the underside of an animal or plant; abdominal.

A sucking disc formed by the pelvic fins in certain fishes.

Fleshy, longitudinal ridge running along the abdomen and caudal peduncle in some fishes.

Lower edge or margin.

Either of the pair of fins, also known as pelvic fins, attached to the pelvic girdle in fishes that help control the direction of movement. Correspond to the hind legs in higher vertebrates and vary in position depending on taxon. Sometimes absent entirely.

Vernacular nerm used to describe the post-spawning behaviour of cupping or clamping of the ventral fins in order to transport fertilised eggs.  Exhibited by females of some Corydoras species, for example.

Positioned or orientated between the ventral and lateral surfaces.

Relating to or situated on or close to the abdomen or lower surface of an animal’s body; abdominal

Having a pattern consisting of irregular, worm-like lines.