Aquarium Glossary
Acidic: A water condition which has a pH lower than 7.0. A trend towards acidic water may be a sign of overfeeding.
Actinic: A type of lighting that provides the proper spectra for photosynthesis. Best used for aquariums with live plants or chlorophyll containing species such as reef coral.
Activated Carbon: Solid carbon which is used to adsorb impurities from the water, fresh or marine. It is also useful for removing unused ozone from the air.
Adipose Fin: A small fleshy fin located behind the dorsal fin and in front of the caudal fin. It is usually only found on characins.
Alkaline: A water condition which has a pH higher than 7.0.
Air Pump: A pump which is used to deliver air to the aquarium. The pump pushes air through silicon tubing and to air stones or other aquatic decor. They are also an essential for UGF's (undergravel filters). An airstone is placed in each clear tube. When the air bubbles travel upward, they generate steady current which brings water from the bottom, through the tubes and to the surface.
Algae: Algae are classified as plants, although they share many characteristics with monerans (fungus). It is that pesky green stuff that many hobbyists try to avoid. It may become slimy over time and will grow in fresh or marine water.
Ammonia: This is the first step in the nitrogen cycle. Ammonia is generated by fish urine and by the decay of dead fish and plant material. It is perhaps the deadliest agent to tropical fish. Care must be made to ensure that the ammonia levels stay at zero.
Ammonia Tower: A biological filtration system which consists of a plastic chamber with a biological filtration media. Water runs through the media, which mixes with the air, and reacts with the bacteria which serve to remove ammonia and nitrites. It is this wet / dry exchange that promotes bacterial growth. Most commonly referred to as a wet/dry filter.
Anaerobic: Living without oxygen. This is a living situation most commonly associated with "bad" bacteria.
Anal Fin: The fin which lies beneath the body, just in front of the caudal fin.
Aerobic: Living with oxygen.
Aragonite: This composes the calcium carbonate skeletons of reef coral and some shells.
Artemia: A very common food for fresh and marine water fish. They are very tiny crustaceans that are easy to breed and maintain for long periods of time. They are a great source of food for young fry. They grow to about 3/4 inches max.
Bacteria: Small single celled organisms from the Moneran kingdom. They are known as prokaryotes, which are classified together because they lack nuclear membranes. They are the most primitive living beings, but help in the nitrogen cycle.
Ballast: The power supply for fluorescent and metal halide lighting.
Biological Filtration: A loose term which describes the process of removing harmful compounds with bacteria. Actually, it is not filtration at all. Instead, it is the mixing of aquarium water with beneficial bacteria that transform harmful material into unharmful compounds. This process is accomplished by trickle filters (ammonia towers), UGF (undergravel filters) and various other specialty filters.
Barbel: Finger like projections most often found on the mouth of certain fish like catfish and loaches. They are used in the search for food.
Berlin Method of Filtration: A biological method of filtration which involves only live rock and a protein skimmer.
Brackish Water: A type of water which is between fresh and marine climates. It is usually found where large lakes or rivers flow into the ocean. The salinity leans towards freshwater.
Brine Shrimp: A very common food for fresh and marine water fish. They are very tiny crustaceans that are easy to breed and maintain for long periods of time. They are a great source of food for young fry. They grow to about 3/4 inches max.
Bubble Filter: This type of filter involves a few long, plastic tubes which remain upright in the aquarium and are attached to a plate on the bottom. In each tube is an air stone attached to an air pump. As the air bubbles rise, a current is generated which continuously brings water from the aquarium, through the substrate and to the top of the tubes.
Bubble Nest: A term used for a nest which is suspended by a weave of tiny air bubbles. It is used as a protective coating for the eggs and the newly hatched young. It is most commonly used by the anabantids.
Buffer: A substance used to treat the water and to counteract changes in the pH.
Caudal Fin: The caudal fin is another name for the tail.
Cannister Filter: A filter which pushes water through an external canister which contains a filter media such as filter floss, polyester or carbon.
Carbon Dioxide: It is a molecule known as CO2, which is a biproduct of respiration. Plants require CO2 to photosynthesize, which generates molecular oxygen.
Caudal Penduncle: The long, narrow section which leads into the caudal fin (tail).
Chemical Filtration: The process of filtering the water through a chemical substrate, most often activated carbon.
Chiller: An air conditioner for water. Acts in the reverse of an aquarium heater.
Chloramine: Municipal water treatment and storage facilities use chloramine to treat water. It is easily removed with many commercially available additives. It is toxic to aquatic animals.
Chlorine: Municipal water treatment and storage facilities use chlorine to treat water. It is easily removed with many commercially available additives. It is toxic to aquatic animals.
Cichlid: A generic term referring to a group of freshwater fish commonly found in India, South America and Africa.
Cirri: Short, stubby organs located above the eyes of some coldwater species.
Deionizer: A filtration device used to purify tap water before it is introduced into the aquarium. They are normally composed of many chemical and mechanical filtration media.
Detritus: A mass of dissolved organic compounds. It is often noticeable as a layer of oily stuff or gunk that builds up in mechanical filter systems or undergravel filters.
Diatoms: Single celled protists with silica shells.
Diatom Filter: Filters which use a diatomic filter media. Diatoms are small single celled protists which have silica shells.
Dorsal Surface: The top part of the fish.
Dorsal Fin: The dorsal fin is the uppermost fin, located between the body and the tail.
Dosing Pump: A pump which serves to maintain a specific water level in an aquarium. They can also be used to add a constant supply of additives or trace elements, much like a hospital IV.
Egg-Layer: A method of reproduction in which the female fish lays eggs and the male sprays them with milt (sperm.) This is the most common method of reproduction; the others are live bearers.
Egg Spots: Marks located on the rear of the body, especially on the anal fin of the male.
External Filter: A filtration device which is kept outside of the aquarium.
Family: A scientific order of taxonomy which contains genera, or genus.
Fish: The purpose of life.
Fry: Newly hatched or born fish.
Genus: A scientific order of taxonomy which contains the
names of species.
Gill: This is the respiratory organs used by fish. It allows
dissolved oxygen to
be extracted from the water in which the fish swim.
Gill Cover: A hard, bony plate which covers the gills.
Gonopodia: An modified anal fin which is elongated. Only
appears on the males.
Gravid: A pregnant female livebearer or female who is ready
to lay eggs.
Hard Water: A water condition which has a lot of dissolved
salts.
HO lighting: High Output fluorescent lighting.
Hydrogen Sulfide: A molecule composed of a hydrogen and
sulfur atom. It is a toxic
compound which has a rotten egg odor. It is synthesized anaerobically by
unwanted bacteria.
Internal Filter: A filtration unit which is kept inside the
aquarium.
Invertebrates: Scientifically speaking, they are any animal
which lacks a backbone.
It is most commonly used to describe coral, but scientifically describes
snails and other
shelled fish.
Iodine: A diatomic molecule consisting of two iodine
elements. It is needed by
reef invertebrates. Protein skimming may deplete the supply, so additions
are quite necessary.
Kalkwasser: A term referring to water with dissolved calcium
hydroxide. It is used
to add inorganic calcium to the water.
Killifish: A very beautiful group of fish which can be quite
hard to find.
Labyrinth Organ: An organ found on anabantids (labyrinth
fish.) They are wrinkled
areas located above the eyes, which enable them to take in oxygen from the
water surface, or when
on land.
Live Rock: A term used to associate the many strains of
bacteria on rock which has
been removed from part of a tropical reef. Live rock is essential for reef
aquaria as it
initiates and maintains the nitrogen cycle. It is the main element in the
berlin method of
filtration.
Livebearer: A fish which gives birth to live young.
Mechanical Filtration: Filtration which serves to eliminate
particles from the
water. It is usually filters water through a substrate such as polyester,
which can remove
impurities as it passes through the media.
Metal Halide Lighting: Metal halide is considered by many to
be a best method of
lighting reef tanks. They burn much hotter than incandescent, high output
(HO) and very high
output (VHO) lighting. They deliver a very wide spectra of light which is
in close association to
natural light.
Milt: Sperm.
Mouth Brooder: Fish which protect unhatched eggs in the
mouth. Sometimes called
tooth-carps.
Nitrification: This is the process in which the nitrogen
cycle works. Ammonia is
created by urea and decomposition. Ammonia is turned into nitites by
nitrosomonas bacteria.
Nitrites are less harmful than bacteria, but still pose a threat. Nitrites
are converted to
nitrates by nitrobacter. Nitrates are much less toxic and is used as
fertilizer for live plants.
It is harmful in great quantities, however, and should be avoided in the
reef tank. There are
special denitrifying filters which convert nitrates to nitrogen gas, which
is explosive in high
quantities.
Nitrate: Chemically speaking, it is the molecule NO3, which
contains a nitrogen
atom, three oxygen atoms and a lone pair of electrons. It is the last stage
of the aquarium
nitrogen cycle and is converted from nitrites. It is harmful to aquatic
animals in high
concentrations.
Nitrites: Chemically speaking, it is the hybridized molecule
NO2, which contains a
nitrogen atom and two oxygen atoms. It is converted from free ammonia and
is harmful at any
level.
Nitrogen Cycle: Ammonia is created by urea and
decomposition. Ammonia is turned
into nitites by nitrosomonas bacteria. Nitrites are less harmful than
bacteria, but still pose a
threat. Nitrites are converted to nitrates by nitrobacter. Nitrates are
much less toxic and is
used as fertilizer for live plants. It is harmful in great quantities,
however, and should be
avoided in the reef tank. There are special denitrifying filters which
convert nitrates to
nitrogen gas, which is explosive in high quantities.
Nuchal Hump: An enlarged forehead on males cichlids.
Operculum: A hard, bony plate which covers the gills.
Ozone: Ozone gas is a molecule which consists of three oxygen
molecules. It is
naturally occurring in the earth's atmosphere at all levels and is essential
to reef keeping.
Ozone functions by sterilizing the water and relieving it of unwanted
bacteria and microscopic
organisms. Ozone is explosive and is harmful to fish and to humans, if in
large quantities.
Peat: Peat is a moss which is used to soften water and to
decrease the pH.
pH: The pH of water is a scientific measurement that
describes how acidic or
alkaline (basic) the water is. A pH of 7 is neutral. Most freshwater fish
prefer a neutral pH,
or a pH between 6.5 and 7.5 Cichlids generally prefer a lower pH whereas
livebearers prefer a
slightly alkaline environment. Marine fish generally prefer a pH between
8.1 and 8.3.
Pectoral Fins: Fins located behind the gill covers. They are
generally smaller and
very delicate.
Pelvic Fins: Fins which are located in front of the anal fin,
just under the head.
Pharyngeal Teeth: Sometimes known as false-teeth or characin
teeth. They are teeth
which lie in the throat of some characins. In these species, there are no
teeth in the mouth.
Photoperiod: Refers to the number of consecutive hours that
light occurs in a day.
In the aquarium, it is the number of hours that the lights are kept on.
Pl*co: Another name for Pleco, or Plecostomus. A superstition
on the internet where if you spell "Pleco" correctly, your pleco will soon
die. That is why this word "Pl*co" was created.
Phosphorous: An important trace element in the marine tank.
Phosphorous is an
element that helps composed ATP (adenosine triphosphate) which is a building
block for genetic
material, specifically DNA (deoxyribonucleic acid).
Plankton: The most minute and primitive creatures of the food
chain. They are tiny
organisms that drift through the layers of the ocean and serve as food for
many small aquatic
species.
Powerfilter: A powerfilter is a generic term used to describe
any type of
filtration that is powered by an electric pump.
Powerhead: A power head is a small, submersible pump which is
used to power
wavemakers and UGF's (undergravel filters).
Prefilter: A prefilter is used mainly in marine tanks to
remove large particles as
the water leaves the tank, enroute to the sump.
Protein Skimmer: A protein skimmer is perhaps the most
important piece of hardware
for the salt water tank. It is a filter used to remove organic impurities
from the water. Water
is sent through a fractionating column where many tiny air bubbles are
pushed through it. The air
bubbles generate "foam", which actually consists of organic impurities. The
"foam" is channeled
out of the device and is kept in a collection cup until it can be discarded.
There are three main
classes of skimmers: counter current, co-current and venturi.
Ray: The bones which make up the skeleton in the fins.
Redox: This is a scientific term referring to the
reduction-oxidation potential of
the water. Its measurement gives an indication of how an aquarium will be
able to sustain life.
A high value is better than a low. The redox potential refers to an
electrical charge on a
molecule that has transformed in a chemical reaction. In a nutshell, it
tells you how easily
chemical reactions are taking place in the tank.
Reactor: This is a device used to force a controlled reaction
with a given
substance. The most common reactor is an ozone reactor, which forces water
through a pressurized
column of an air-ozone mixture.
Reverse Osmosis: This is a purification method for tap-water.
Prefiltered tap
water is pushed through a reverse osmosis membrane. Water that makes it
through is considered
pure, while water that does not, is sent through a special tube and is
rendered impure. As it
relies on water which is able to pass through the membrane, it also
generates a large quantity of
"waste" water which cannot be used. This is one of the best, but slowest
methods of tap water
purification. Reverse Osmosis units produce purified water at extremely
slowly, sometimes as low
as 10 or 15 gpd (gallons per day).
Salt: A generic term which scientifically refers to a cation
and an anion.
However, in aquatics, it refers to the proper combination of inorganic
salts, composed mainly of
sodium and magnesium chloride.
Scale: Small places which are scattered throughout the body
of the fish. They are
the primary source of protection for most fish.
Scalpel: A spine which is located on the tail base of
surgeonfish (tangs). It is
retractable and gives them their name, as it looks very much like a scalpel.
Scalpel Marking: A spine which is located on the tail base of
surgeonfish (tangs).
It is retractable and gives them their name, as it looks very much like a
scalpel.
School: A group of fish which swim together, usually composed
of the same species
or sub-species.
Scute: A type of scale most common in catfish.
Silicon: A trace element in the marine system. It is an
element which is a
building block for many organisms with silica shells
Soft Water: A water condition with very small amounts of
dissolved salts.
Spawning: A term used for breeding.
Species: The most useful taxonomical name. Every living
creature is assigned a
unique species name, which is composed of two parts.
Specific Gravity: A scientific term which is used to describe
the salt content of
water.
Strain: A variety of a certain species. The freshwater
guppy, for example, has
only one species name but several strains.
Strontium: A trace element which is essential to the growth
of reef coral.
Subspecies: An offset of a certain species, usually due to
their separation in
nature.
Substrate: Material used on the aquarium bottom. Examples
include gravel, crushed
coral, crushed seashells, et cetra.
Substratum: The many different layers of substrates found in
nature or in the
aquarium.
Sump: A collection container mainly used in marine tanks. As
the water leaves the
tank, it is delivered via gravity to a sump, which is often nothing more
than a small aquarium.
From there, it is pumped through the filtration system and delivered back to
the aquarium.
Swim Bladder: An internal organ that helps fish maintain
normal buoyancy.
Trace Elements: A term used to describe the many necessary
elements in a marine
aquarium, although usually in very small amounts. Among them are calcium,
strontium, iodine and
ozone. (for purification).
Trickle Filter: A biological filtration system which consists
of a plastic chamber
with a biological filtration media. Water runs through the media, which
mixes with the air, and
reacts with the bacteria which serve to remove ammonia and nitrites. It is
this wet / dry
exchange that promotes bacterial growth.
Tubercle: Small white pustules on the gill covers which
exists mainly on freshwater
cyprinids.
Turbulence: Refers to how rapid and strong the water movement
is.
UGF: This type of filter involves a few long, plastic tubes
which remain upright in
the aquarium and are attached to a plate on the bottom. In each tube is an
air stone attached to
an air pump. As the air bubbles rise, a current is generated which
continuously brings water from
the aquarium, through the substrate and to the top of the tubes.
Ultraviolet Sterilizer: A purification method which uses
ultraviolet light to kill
harmful bacteria and micro organisms.
Undergravel Filter: This type of filter involves a few long,
plastic tubes which
remain upright in the aquarium and are attached to a plate on the bottom.
In each tube is an air
stone attached to an air pump. As the air bubbles rise, a current is
generated which continuously
brings water from the aquarium, through the substrate and to the top of the
tubes.
UV Sterilizer: A purification method which uses ultraviolet
light to kill harmful
bacteria and micro organisms.
Ventral Surface: The bottom area of the fish.
Venturi: A popular protein skimmer design. It is a protein
skimmer with a
cylindrical body, used to draw air through a rapid current of water.
VHO Lighting: Very High Output fluorescent lighting. These
lights are powered by
special ballast which deliver a wide spectra light.
Wet/Dry Filter: A biological filtration system which consists
of a plastic chamber
with a biological filtration media. Water runs through the media, which
mixes with the air, and
reacts with the bacteria which serve to remove ammonia and nitrites. It is
this wet / dry
exchange that promotes bacterial growth.
Zeolite: An ammonia removing substance. It can only be used
in freshwater tanks.