Not selective, especially used in reference to sexual behaviour. Sometimes used in reference to the reproductive behaviour of certain fishes.

See cleithrum.

Exhibiting protandry.

Form of sequential hermaphroditism in which male offspring become female at some point during their life cycle.

Mechanical device used to remove organic compounds in marine aquaria via the process of foam fractionation.

Exhibiting protogyny.

Form of sequential hermaphroditism in which female offspring become male at some point during their life cycle.

Plural of protozoan.

Any member of a diverse group of unicellular eukaryotic organisms including amoebas, ciliates, flagellates, and sporozoans. Also spelled protozoon.

See protozoan.

Capable of being protracted; extensible.

Capable of being extended or thrust forwards. Often used in reference to the jaws of certain fishes.

Located close to or towards the point or origin of attachment or a central point of the body. Opposite of distal.

Accessory or spurious gill, often located on the inner surface of the operculum in various fishes, that is usually small and sometimes completely obscured beneath the epithelium. Also referred to as pseudobranchia.

Translucent, triangular area in the humeral region, behind the opercle, without muscle and where the anterior part of the gas bladder is in direct contact with the skin. It is hypothesised to function as a hearing aid in many juvenile characoids and is present in adults of certain species, notably members of the family Cheirodontidae.

Bony or cartilaginous structures via which the rays of the median fins articulate and connect to the body.

Paired bone in the roof of the mouth connecting the palatine anteriorly to the quadrate posteriorly.

Having or marked with small spots, depressions, or holes.

Having or covered with pustules.

Small, raised spot resembling a blister or pimple.