Results for “designation”

designation

In icthyology, the nomenclatural act by which the type specimen of a previously or newly-established genus, subgenus, species, or subspecies is fixed via an express statement.

Used in 6 profiles

type designation

Determination and selection of the type of a taxon.

bioball

Type of biological filter medium consisting of a plastic ball designed in such a way that the available surface area for bacterial colonisation is maximised. The precise form differs depending on manufacturer.

breeding trap

Net or plastic container suspended or floated in an aquarium and used to isolate gravid female livebearers or fry collected from the main aquarium. Available in a number of designs, with plastic ones generally containing two compartments separated by a grille or opening large enough that fry, but not adults, can pass through.

heater

Thermostatically-controlled device used to maintain constant water temperature in an aquarium or pond, also known as a heaterstat. Depending on design, may be installed submersed within the aquarium, sump or substrate (see heating cable) or inline with tubing attached to an external filter. Some types of the latter also have a heating element built in.

Used in 42 profiles

holotype

The single specimen designated as the name-bearing type of a nominal species or subspecies.

Used in 36 profiles

lectotype

In zoological nomenclature, a syntype specimen selected as the name-bearing type of a nominal taxon in the absence of a designated holotype.

Used in 6 profiles

neotype

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.

Used in 14 profiles

paralectotype

In zoological nomenclature, any remaining member of a former syntype series following designation of a lectotype.

Used in 1 profile

refractometer

Instrument used to measure salinity or specific gravity via the refractive index (basically, the degree that light bends when shined through something) of a liquid. Most models are designed to measure sodium chloride or brine solutions and not seawater which contains a more complex range of salts and minerals, but usually more accurate than a hydrometer nevertheless.

seine

Type of net designed to hang vertically in the water with the ends being manually drawn together to catch fishes, and which usually has weights at the lower edge and floats at the top; to fish with such a net.

syntype

Any specimen within a type series if no holotype or lectotype has been designated, the syntypes collectively representing the name-bearing type.

Used in 2 profiles

type series

Series of specimens which either constitutes the name-bearing type of a nominal species or subspecies, or from which the name-bearing type has been or may be designated

Used in 120 profiles

valence

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.

weir

Low dam constructed across a river to raise the water level, divert the water, or control its flow; series of traps or enclosures designed to catch fishes.

Used in 1 profile

wet/dry filter

Type of filter normally placed under the aquarium, and often home-made. The basic premise is that water trickles vertically downards through separated compartments containing mechanical and biological filter media with spaces inbetween so that it is also exposed to the air briefly. It then collects in a base chamber or sump from where it is pumped back to the main aquarium. There are many commercial designs available, some of which are more effective than others. Not popular in marine reef aquaria due to the associated accumulation of nitrates as by-product.