Terms, Terms, Abbreviations, Terms, Acronyms, Terms...
It's not easy... Gotta catch up...
Getting a bit lost with some of the terminologies, acronyms and abbreviations in the hobby? Below are some commonly used ones you'll probably bump into as well.
Gradual introduction of new fish to an aquarium by equalizing the temperature and chemical parameters of their container water with that of the tank. More importantly, it is the process of the marine life form getting accustomed to captive life. Acclimation continues as the fish (for instance) grows accustomed to its owner, foods provided, tank mates, etc.
A clear plastic material used to construct aquariums. It is half the weight of glass and its refractive index is closer to that of water than glass, making it more transparent. Acrylic is more easily scratched than glass. Also called Plexiglas.
A type of fluorescent bulb that gives off blue colored light often used in marine aquaria to make corals appear to glow with brilliant colors and to give the tank a "deep ocean" feel to it.
Activated Carbon
A Filter Medium used to remove organic contaminants or residual medications from aquarium water. If used it must be renewed at regular intervals.
Existing or active in the presence of free oxygen. Requiring oxygen for a process (such as respiration).
Plant-like organisms which grow in water and attach themselves to aquarium glass, plants, rocks, decorations, etc.
Algal Bloom
An explosive growth of algae which discolors the water and can lead to oxygen depletion.
Ammonia Wastes
These are chemicals containing ammonia produced by marine fish and some marine life forms, in their normal excrement. Ammonia is formed by the breakdown of organic material, deadly to marine fishes in very low concentrations. More than just marine fish produce these wastes. Such wastes are produced by bacteria and other microbial life forms for example, when the necessary nutrients (organic material like leftover fish foods) are available to them.
Any member of the invertebrate order Amphipoda (class Crustacea) inhabiting all parts of the sea, lakes, rivers, sand beaches, caves, and moist (warm) habitats on many tropical islands. Marine amphipods have been found at depths of more than 9,100 m (30,000 feet). Freshwater and marine beach species are commonly known as scuds; those that occupy sand beaches are called sand hoppers, sideswimmers or sand fleas (see sand flea). About 6,000 species have been described.
A general term used by aquarists (sometimes) to describe a place in the marine aquarium when oxygen is in short supply – not void of oxygen; just low in oxygen – enough so that denitrification may occur.
Anal Fin
Fin just behind anal opening.
Where Nemo lives :-). A sea anemone is a polyp attached at the bottom to the surface beneath it by an adhesive foot, called a pedal disk, with a column shaped body ending in an oral disk. Most are from 1.8 to 3 centimetres (0.71 to 1.2 in) in diameter, but anemones as small as 4 millimetres (0.16 in) or as large as nearly 2 metres (6.6 ft) are known. A few species are pelagic, and are not attached to the bottom; instead they have a gas chamber within the pedal disc, allowing them to float upside down in the water. They can have anything from a few tens of tentacles to hundreds. Sea anemones are a group of water dwelling, predatory animals of the order Actiniaria; they are named after the anemone, a terrestrial flower. As cnidarians, sea anemones are closely related to corals, jellyfish, tube-dwelling anemones, and Hydra.
The artistic arrangement of plants, rocks, and driftwood to create a harmonious and aesthetically pleasing display in an aquarium.
A form of calcium carbonate which constitutes the shells of corals and other marine creatures. Crushed aragonite sand is sometimes used as a substrate when it is desired to raise the pH/Hardness of the tank water above its natural level.
A genus of phyllopod Crustacea found in salt lakes and brines. Brine Shrimps (Please see BBS).
Arthropod are invertebrate animals having an exoskeleton (external skeleton), a segmented body, and jointed appendages. They are members of the Phylum Arthropoda, and include the insects, arachnids, crustaceans, and others. Arthropods are characterized by their jointed limbs and cuticles, which are mainly made of α-chitin; the cuticles of crustaceans are also biomineralized with calcium carbonate.
Artificial Rock
Cement or man-made shaped materials to act like live rock. Called ‘homemade rock’ too. Even though artificial rock may be placed next to live rock, it will only have the bacteria, algae, pods, and mobile organisms that can move from the live rock to artificial rock. Some artificial rock is placed in the ocean where it can age and turn into a version of live rock. This is aquacultured live rock. The diversity of life on and in this rock depends upon a few factors such as the kind of material, the number of years it sat in the ocean, and the marine lifeforms in the area/environment. The concept of putting barren artificial rock or base rock next to live rock in order to ‘make’ live rock out if is a false hope. The base and artificial rock will only take on the organisms that are mobile, bacteria, algae, etc. and never truly become ‘live rock.’ Please see "Live Rock".
Asexual Reproduction
Asexual means having no sex or sex organs, therefore asexual reproduction would be reproducing by means other than sex. Please see "Sexual Reproduction".
A German term that is used to refer to Algae growing on rocks, driftwood, etc. If not excessive it can be decorative and provides food for some types of fish and Inverts.
Baby Brine Shrimp. Larvae of brine shrimp, crustaceans of the genus Artemia. Cultivated as food for fry and small fishes.
Base Rock
In general terms, it is marine suitable rock void of non-microbial life (Remember, the bacteria responsible for nitrification will attach to any surface area). Please see "Live Rock".
Benthos and benthic refers to living on or under the substrate at the bottom of aquatic environments including lakes, ponds, rivers and streams, and oceans.
Berlin System
It is a marine system consisting of live rock and live sand as its biological filtration, with circulation to move the wastes to the filter bacteria.
Biodiversity is the variation of life forms within a given ecosystem, biome, or on the entire Earth. Biodiversity is often used as a measure of the health of biological systems. The biodiversity found on Earth today consists of many millions of distinct biological species. The year 2010 has been declared as the International Year of Biodiversity.
A slimy matrix produced and inhabited by bacteria which enables the bacteria to adhere to a surface and carry out certain biochemical processes essential to the Nitrogen Cycle. In open aquatic environments, biofilm supports a microscopic community of various species of bacteria including nitrifying bacteria, algae, protozoa, and microscopic invertebrates. In the aquarium, biofilm covers all surfaces exposed to water, and tends to build up in the dark, undisturbed areas such as the filter intake tube and other filter parts.
Biological indicators are species used to monitor the health of an environment or ecosystem. They are any biological species or group of species whose function, population, or status can be used to determine ecosystem or environmental integrity.
The biological impact put (in this case) onto the marine system. From fish, the biological impact includes gas and solid and liquid wastes. What most hobbyists don’t realize is that the bacteria that handle fish wastes also produce their own biological impact – the consume oxygen and generate their own wastes. Other sources of the bio-load comes from foods and things added to the system, as well as those things that are dying. The amount/quantity of bio-load a marine system can handle is determined mostly upon the biological filter used, circulation, filtration and add-on equipment.
Biological Filter
The name given to the process where bacteria convert ammonia wastes to nitrites and then converts nitrites to nitrates. This part of the biological filter is called nitrification. Some aquarists also think of a part of the biological filter as converting nitrates to nitrogen gas and other chemicals. This part of the process is called denitrification. When asked, ‘What kind of biological filter are you using’ it means are you using live rock, an under gravel filter, a canister filter, etc. to hold the bacteria that perform the nitrification process.
Biology is a natural science concerned with the study of life and living organisms, including their structure, function, growth, origin, evolution, distribution, and taxonomy.
A natural region or geographical space that presents relative uniformity of physical characteristics and animal/plant populations which inhabit it.
Biotope Aquarium
An aquarium that is designed with the intent to reproduce an existing natural habitat or niche, in terms of its physical/visual characteristics and its naturally occurring species.
A process by which corals expel their colorful zooxanthellae and turn white or pale.
Slightly salty water typical of river estuaries and lagoons. Some fish, e.g. archer-fish, gobies, and puffers require a brackish aquarium set-up to thrive.
Water saturated with or containing large amounts of a salt, especially sodium chloride. The high salt content is usually due to evaporation or freezing such as in the formation of sea ice.
Bristle Worm
A marine animal that often come with live rock. They burrow into the substrate, but (without any threats from fish) will swim into the open to find new eating grounds. In the group known as Polychaetes, bristle worms number at least 10,000 species. Very few are bad; some can sting a human bare hand; others can damage corals; but most, especially those of the Eurythoe sp. are very useful. They are usually less than a few inches long (down to less than half an inch), pink to orange with white bristles, sometimes with a bluish line running along the center of the body. They eat detritus, pods, and keep the substrate moving around and provide additional food for some fishes that eat them.
Buffering Capacity
Buffering Capacity or Alkalinity - The ability of water to maintain a stable pH. Controlled by the amount of carbonate ions present in the water.
Any substance formed of or containing calcium carbonate.
Canister Filter
An external Filter consisting of a sealed canister containing various Filter Media and a pump which circulates water through the media. It is attached to the aquarium by inlet and outlet hoses.
Captive Bred
Captive Bred or CB - Animals that are the offspring of animals which were themselves born or hatched in captivity. It may also refer to an animal bred in captivity from wild caught (WC) parents. Captive bred animals are generally healthy and parasite free and acclimatise well in captive life. They will generally readily feed on easily obtainable food (such as frozen or other prepared food). Captive breeding is the process of breeding animals in human controlled environments with restricted settings, such as wildlife preserves, zoos, conservation facilities, and commercial breeding farms; sometimes the process is construed to include release of individual organisms to the wild, when there is sufficient natural habitat to support new individuals or when the threat to the species in the wild is lessened. This helps to ensure survival of species that would otherwise go extinct in the wild. Please see "Captive Environment" and "Wild Caught".
Captive Environment
Referes to the "new home" provided to animals in captivity, under human care. Captivity can be used as a generalizing term to describe the keeping of either domesticated animals (livestock and pets) or wild animals. This may include for example farms, private homes and zoos. A good captive environment is one where animals can acquire and retain the behavioral skills they would need to cope successfully with their natural environment were they ever to be released in the wild. This will allow them to develop and display the skills they would need for survival.
CO2 - Carbon Dioxide
Carbon dioxide. A colourless odourless incombustible gas formed during respiration, the decomposition and combustion of organic compounds, and in the reaction of acids with carbonates.
A meat-eater. Marine life (fish in this case) that obtains its protein from animals. Such fishes eat other fishes and other animal marine lifeforms. In captivity, some will eat sea vegetables, too, but at least a large portion of their diet must be whole animal sea foods.
Caudal Fin
The "tail fin." In many species this is the main fin associated with propulsion.
It's a fast growing attractive macroalgae of which there are many variations with leaves that look like ferns, grapes, etc. Not surprisingly, the different types are named after the look of their leaves. Caulerpa is common in the aquarium hobby, especially placed in refugiums, as a nitrate absorber because of its prolific growth under relatively adverse conditions. All grow rapidly by sending out runners which are held in place by root like holdfasts. It is also known to undergo sexual reproduction by producing both types of gametes inside the same plant. They are easily detected in the field due to reticulate depigmentation and development of papillae mostly on the frond axes. After the gametes have been released, the parental plant dies. During sexual reproduction, Caulerpa also releases absorbed nutrients which can be fatal to a closed system.
Chaetomorpha Algae, also known as Spaghetti Algae or Green Hair Algae, is an excellent macro algae for refugiums. It is especially common in saltwater aquariums because it can be used for removal of nutrients, especially nitrates and phosphates. This algae is fast growing and is not palatable to many herbivorous species. Chaetomorpha is preferred over other macroalgae such as Caulerpa because it is less likely to undergo sexual reproduction in the aquarium.
Chemical filter
A means to remove wastes from the marine system by use of reactions. Sometimes also includes absorbents (like resins and activated carbon) which sometimes are more ‘mechanical’ than ‘chemical’ in nature. Such filters include those that remove nitrates, phosphates, etc. by ‘reactors.’
Combination of Chlorine and Ammonia that is frequently added to municipal water supplies to maintain municipal water quality standards. Also prevents the establishment of Biofilm in municipal water supply lines and storage containers. It is toxic to fish and amphibians. Can be removed by treating water with a Water Conditioner that is specifically formulated to treat chloramines.
A substance used in municipal water supplies to kill bacteria. Chlorine is toxic to fish and invertebrates and must be removed from water before it can be added to the tank. A number of products are available for this purpose.
Cleanup Crew
Those marine lifeforms introduced into a marine system to perform one or more functions. These lifeforms may consume nutrients, algae, left over foods, detritus, detritivore, and microbes to name a few. They may perform certain needed or desirable functions like stirring the substrate. These life forms include snails, worms, some detritivore marine lifeforms, crabs, nudibranch, urchins, starfish, cucumbers, etc.
Community Tank
An aquarium which is populated with fish of several different species, all of which are compatible with one another.
Conservation is an ethic of resource use, allocation, and protection. Its primary focus is upon maintaining the health of the natural world: its, fisheries, habitats, and biological diversity. Secondary focus is on materials conservation and energy conservation, which are seen as important to protect the natural world. Those who follow the conservation ethic and, especially, those who advocate or work toward conservation goals are termed conservationists.
Refers to animals of the same species.
Are a group of small crustaceans found in the sea and nearly every freshwater habitat. Many species are planktonic (drifting in sea waters), but more are benthic (living on the ocean floor), and some continental species may live in limno-terrestrial habitats and other wet terrestrial places, such as swamps, under leaf fall in wet forests, bogs, springs, ephemeral ponds and puddles, damp moss, or water-filled recesses of plants. Many live underground in marine and freshwater caves, sinkholes, or stream beds. Copepods also serve as a food source and are sometimes used as bioindicators.
Coralline Algae
An encrusting form of algae that forms calcareous crusts like coral. Coralline algae is very colorful, occurring in bright purple, pink and red colors. It is very desirable in the reef tank, and can be made to grow on rocks and other hard surfaces by maintaining optimum pH, alkalinity and calcium levels.
Coral Reef
Coral reefs are underwater structures made from calcium carbonate secreted by corals. Most coral reefs are built from stony corals, and are formed by polyps that live together in groups. The polyps secrete a hard carbonate exoskeleton which provides support and protection for the body of each polyp. Reefs grow best in warm, shallow, clear, sunny and agitated waters.
Corals are marine organisms in class Anthozoa of phylum Cnidaria typically living in compact colonies of many identical individual "polyps". The group includes the important reef builders that inhabit tropical oceans, which secrete calcium carbonate to form a hard skeleton.
Corexit is a product line of solvents primarily used as a dispersant for breaking up oil slicks. The same product was used during the 1989 Exxon Valdez oil spill disaster in Alaska (Corexit 9580). In 2010, Corexit EC9500A and Corexit EC9527A are being used in unprecedentedly large quantities in the Deepwater Horizon oil spill, such as in the recent Gulf Oil Spill.

The relative toxicity of Corexit and other dispersants are difficult to determine due to a scarcity of scientific data. The manufacturer's safety data sheet states "No toxicity studies have been conducted on this product," and later concludes "The potential human hazard is: Low." According to the manufacturer's website, workers applying Corexit should wear breathing protection and work in a ventilated area. Compared with 12 other dispersants listed by the EPA, Corexit 9500 and 9527 are either similarly toxic or 10 to 20 times more toxic. In another preliminary EPA study of eight different dispersants, Corexit 9500 was found to be less toxic to some marine life than other dispersants and to break down within weeks, rather than settling to the bottom of the ocean or collecting in the water. None of the eight products tested are "without toxicity", according to an EPA administrator, and the ecological effect of mixing the dispersants with oil is unknown, as is the toxicity of the breakdown products of the dispersant.

Corexit 9527, considered by the EPA to be an acute health hazard, is stated by its manufacturer to be potentially harmful to red blood cells, the kidneys and the liver, and may irritate eyes and skin. The chemical 2-butoxyethanol, found in Corexit 9527, was identified as having caused lasting health problems in workers involved in the cleanup of the Exxon Valdez oil spill. According to the Alaska Community Action on Toxics, the use of Corexit during the Exxon Valdez oil spill caused people "respiratory, nervous system, liver, kidney and blood disorders". Like 9527, 9500 can cause hemolysis (rupture of blood cells) and may also cause internal bleeding.

According to the EPA, Corexit is more toxic than dispersants made by several competitors and less effective in handling southern Louisiana crude. On May 20, 2010, the EPA ordered BP to look for less toxic alternatives to Corexit, and later ordered BP to stop spraying dispersants, but BP responded that it thought that Corexit was the best alternative and continued to spray it. Reportedly Corexit may be toxic to marine life and helps keep spilled oil submerged. There is concern that the quantities used in the Gulf will create 'unprecedented underwater damage to organisms.' Nalco spokesman Charlie Pajor said that oil mixed with Corexit is "more toxic to marine life, but less toxic to life along the shore and animals at the surface" because the dispersant allows the oil to stay submerged below the surface of the water. Corexit 9500 causes oil to form into small droplets in the water; fish may be harmed when they eat these droplets. According to its Material safety data sheet, Corexit may also bioaccumulate, remaining in the flesh and building up over time. Thus predators who eat smaller fish with the toxin in their systems may end up with much higher levels in their flesh.
Crustaceans (Crustacea) form a very large group of arthropods, usually treated as a subphylum, which includes such familiar animals as crabs, lobsters, crayfish, shrimp, krill and barnacles.
Curing Live Rock
With regards to marine systems, this is the process to get rid of decomposing and dead organic materials in and on live rock. There is die off at almost every stage of handling of live rock coming into the retailer. If put directly into an aquarium, it would create a lot of pollution and slow down the maturing process of the aquarium. Thus curing such rock outside of the aquarium is usually the best course. If the rock is sold a ‘cured live rock’ the buyer should ask what this means and whether or not some curing will still to be done, and if so, to what extent. Minor curing in a newly setup (no fish or higher/sensitive inverts in yet) aquarium is okay, but no curing of rock should be done in an established marine system.
Cyanobacteria (also known as blue-green algae, blue-green bacteria, and Cyanophyta) is a phylum of bacteria that obtain their energy through photosynthesis. Cyanobacteria can be found in almost every conceivable environment, from oceans to fresh water to bare rock to soil. They can occur as planktonic cells or form phototrophic biofilms in fresh water and marine environments, they occur in damp soil, or even temporarily moistened rocks in deserts. In the hobby, it is commonly referred to as red slime algae (although it is not really an algae), usually caused by poor water quality with excessive nutrients.
The demersal zone is the part of the sea or ocean (or deep lake) comprising the water column that is near to (and is significantly affected by) the seabed and the benthos. The demersal zone is just above the benthic zone and forms a layer of the larger profundal zone.
The process of converting nitrates into nitrogen gas and other compounds. This is a part of the nitrogen cycle performed by bacteria that don’t like an environment with oxygen in it. These bacteria are anaerobic in nature, but many will survive in an anoxic environment. This process may occur in areas of the aquarium when oxygen is in short supply, such as a deep sand bed, inside or in crevices of live rock, where live rock meets the substrate where there is very little water flow, and artificial areas such as a nitrate reactor.
In biology, detritus is non-living particulate organic material (as opposed to dissolved organic material). It typically includes the bodies or fragments of dead organisms as well as fecal material. Detritus is typically colonized by communities of microorganisms which act to decompose (or remineralize) the material. In the hobby, it refers to the grayish piles of organic compounds that accumulate in the aquarium. Commonly will contain fish wastes, fragments of rock, leftover food, among other things. Usually detritus will accumulate in low water flow areas, sumps, etc.
DSB - Deep Sand Bed
A term to describe a substrate in the marine system that is deep enough to create anoxic conditions so that denitrification may occur. The particle size and depth are important to the efficiency of the deep sand bed, sometimes abbreviated DSB. These can be setup in the display tank, sump, and/or refugium. They usually begin at about 4 inches deep and go as deep as 6 inches. Its depth and efficiency is based upon particle size.
A diatom is any of a class of microscopic one-celled algae having walls of silica consisting of two interlocking valves. In the hobby, they are known to be the organisms commonly forming brown films on aquarium glass or rocks. Diatoms form their shells from silicate, and can be controlled to some degree by preventing the addition of this compound through the use of purified water.
Is a term which refers to the amount of organisms in and on the live rock that die during shimpment when the rock is only moist and/or is exposed to air. This is one of the reasons why it is recommended to cure live rocks first and NOT add them directly to a running system, as the amount of dead and decomposing organisms can create an ammonia spike which is lethal to most fish and invertibrates. On the other hand, this is the very reason why some aquarists use live rocks to jump start or cycle their tanks. Please see "Live Rock".
The dinoflagellates are a large group of flagellate protists. Most are marine plankton, but they are common in fresh water habitats as well. About half of all dinoflagellates are photosynthetic, and these make up the largest group of eukaryotic algae aside from the diatoms.
Dither Fish
A fish that comes forward to see its owner, doesn’t hide much (usually swims in the open), peaceful, and eats well, yet isn’t overtly competitive with tank mates. This fish is put in with a timid fish to teach it to be less afraid and to eat.
An organism that is active during the day, and sleeping at night.
DI Water
Water that has been purified by deionization.
Dorsal Fin
The fin directly on the top of the body (it's the fin that sticks out of the water when you see a shark). Some fish have two dorsal fins one directly behind the other.
Ecdysis is the molting of the cuticula in arthropods and related groups (Ecdysozoa). Since the cuticula of these animals is also the skeletal support (the exoskeleton) of the body and is inelastic, it is shed during growth and a new, larger covering is formed. Ecdysis is necessary because the exoskeleton is rigid and cannot grow like skin. The new exoskeleton is initially soft but hardens after the moulting of the old exoskeleton.The old, empty exoskeleton is called an exuvia (or "exuvium"). Please see "Molting".
Ecology is the scientific study of the distributions, abundance and relations of organisms and their interactions with the environment. Ecology includes the study of plant and animal populations, plant and animal communities and ecosystems. Ecosystems describe the web or network of relations among organisms at different scales of organization. Since ecology refers to any form of biodiversity, ecologists research everything from tiny bacteria's role in nutrient recycling to the effects of tropical rain forest on the Earth's atmosphere.
Egg Layer
Species of fish where the female lays eggs which are externally fertilized by the male. The most common method of fish reproduction.
An endangered species is a population of organisms which is at risk of becoming extinct because it is either few in numbers, or threatened by changing environmental or predation parameters.
Restricted to a particular place. Means the animal lives in a certain place and nowhere else.
A eukaryote is an organism whose cells contain complex structures enclosed within membranes.
External Filter
Any filter that is located outside of the tank, e.g. HOB Filter, Canister Filter.
In biology and ecology, extinction is the end of an organism or group of taxa. A species becomes extinct when the last existing member of that species dies. Extinction therefore becomes a certainty when there are no surviving individuals that are able to reproduce and create a new generation.
Filter Feeder
An organism that filters out nutrients such as plankton, bacteria, or detritus from the water.
Fin Rot
A condition in which the fins are rotted away giving the appearance of ragged, split, or perforated fins.
Fishless Cycle
To Cycle an aquatic system without live fish, using chemical or household ammonia, or decaying material such as fish food or a piece of shrimp to promote the establishment of nitrifying bacteria (as Biofilm).
The marine fish that is scraping itself on aquarium decorations or the substrate appears to be ‘scratching’ an itch. This action causes the belly of the fish to turn sideways. Since the belly of the fish is sometimes lighter in color than the sides of the fish, the fish appears to be ‘flashing’ like a light signal. Hence the behavior was given this name.
Flow Rate
Flow Rate or Circulation - The measure of how much water is flowing/circulating in the display tank. Aquarists put this into terms of ‘turnover’ or how many times the volume of the system is circulated in the display tank. The (total) flow rate is the sum of the flow rates created by each pump. Each (inside) circulating pump flow is added to the return pump flow to provide a total flow rate in the display. For FOWLR the desired flow rate is no less than 8. For a reef tank, the desired flow rate is no less than 16. That is, 16 times the volume of the system is circulated in the display tank every hour. A 100 gallon FOWLR marine system is recommended to have no less than 800 gallons per hour flow rate.
Fish Stock Limit
The maximum quantity of fish that may be put into a marine system. This quantity is properly defined as the amount of total bio-load the fishes put on the system and the system’s ability to handle that bio-load.
Acronym for: Fish Only. Saltwater aquarium containing fish but not Live Rock or Reef animals.
Acronym for: Fish Only With Live Rock. The live rock helps provide the function of sponsoring the bacteria that contribute to the nitrogen cycle, both nitrification as well as some denitrification. For the most part, the marine life in and on the live rock comes and goes both in kinds and numbers. The rock is usually there for appearance, aquascaping to provide the fish with a familiar surrounding, provide fishes with hiding places and territories, and performing biological filtration. The purpose of this marine system is to maintain marine fishes.
Foam Factionation
A method of removing proteins from water through the use of foam. This is the filtration method used by protein skimmers.
Fish larvae (baby fish).
Haploid reproductive cells that unite during sexual reproduction to form a diploid zygote. Male gametes are sperm and female gametes are eggs.
Total Hardness (also referred to as General Hardness). A measurement of the amount of magnesium and calcium dissolved in water. Expressed in degrees of hardness. One degree of hardness equals 17.9 ppm.
The membranes through which fish absorb dissolved oxygen from the water during respiration.
A Gorgonian is a tropical or subtropical octocoral with upright branchy plant-like or fan-like growths and a skeleton made of a horny organic material.
Grow Out Tank
A separate tank into which Fry are transferred until they grow to a size suitable for sale, or until they are large enough to be moved back into the aquarium with adults.
Gut Loading
Gut loading is the process by which an animal's prey is raised and fed nutritious foods with the intention of passing those nutrients to the animal for which the prey is intended. By providing the prey animals with a high quality diet immediately prior to feeding, they become a more nutritious meal for the predator. Several commercial products are available and are fortified specifically for gut loading. These products often include varying combinations of carbohydrates, fats, proteins, vitamins, and dietary fiber.
HOB - Hang On Back Filter
An external filter which is hung on the back of the tank.
HOT - Hang On Tank Filter
A filter which is hung on the tank, either inside or outside. Some are not intended for permanent installation, but only for short-term use, and are placed in front or on the side of the tank.
A social group of female animals of the same species accompanied or dominated by one fertile male who denies other males access to the group. A single male spawns repeatedly with several females, perhaps up to dozen, and the entire harem occupies the same general area of the reef. The male protects his territory, and its resident females, from other males that may be passing through or that occupy adjacent territories.
Head and Lateral Line Erosion
Also known as hole-in-head disease and lateral line disease. A fish with this condition will develop holes in its' head and sometimes along its' lateral line. The main cause is nutritional deficiency, especially vitamin C. Stress and poor water quality also play a role. Untreated cases will cause disfiguring or death. To combat and cure, ensure good water quality and provide vitamin enriched foods, especially vitamin C.
Animals whose diet consists mainly of vegetable matter. They obtain protein primarily from sea vegetables. Although in captivity most herbivores will act as omnivores, the goal is to be sure they get at least 65% of their protein from sea veggies.
Refers to both male and female in the same organism. This occurs either at the same time (synchronous hermaphrodite) or at different times (successive hermaphrodite). When the female form occurs first, this is referred to as protogynous hermaphroditism, otherwise protandrous hermaphroditism.
In the marine aquarium hobby, hitchhikers are marine creatures you get with the live rocks when you bring them to your tank. Most organisms hitchhiking are harmless and add to the diversity of life within our aquariums. This is where the very essence of the name "Live Rock" comes from - the rock is populated by living organisims. Some common hitchhikers are Bristle Worms, Mantis Shrimps, Feather Dusters, Aptasia anemones, Hydroids, Amphipods, Sea Stars, Porcelain Crabs, Emerald Crabs, snails, Sea Cucumbers, etc. To avoid introducing unwanted hitchhikers, cure and quarantine your live rocks.
Hydroids are colonies of polyps. Each polyp is similar to a small sea anemone i.e. has its own jelly like body and a mouth surrounded by tentacles. The difference is that individuals are organised to benefit the whole colony. They do this, by being interconnected via a common tube the stolon. The stolon which can be tough and horny, allows the transfer of food between the polyps. Hydroids can be introduced to a home aquarium through live rocks as hitchhikers.
An instrument or a device used to measure salinity by specific gravity of seawater.
Also known as osmotic shock therapy. The salinity of the salt water is lowered below normal ranges in order to treat only one kind of parasitic attack on marine fishes: Marine Ich (Cryptocaryon irritans). Effective hyposalinity for curing fish of Marine Ich is 1.008 to 1.010 sp. gravity units controlled by the use of a refractometer.
Ichthyology is the branch of zoology devoted to the study of fish. This includes skeletal fish (Osteichthyes), cartilaginous fish (Chondrichthyes), and jawless fish (Agnatha). While a majority of species have probably been discovered and described, approximately 250 new species are officially described by science each year. According to FishBase, 31,500 species of fish had been described by January 2010.[1] There are more fish species than the combined total of all other vertebrates: mammals, amphibians, reptiles and birds. The practice of ichthyology is associated with marine biology, limnology and fisheries science.
Internal Filter
Any filter mounted entirely inside the tank. The sponge filter is the simplest example.
Commonly called inverts by many in the hobby. Invertebrates are animals without backbones like anemones, corals, shrimps, snails, and crabs.
A trace element found in seawater necessary in small quantities for some reef invertebrates, particularly corals and clams.
German word meaning calcium water, kalkwasser is a saturated solution of calcium hydroxide (Ca(OH)2) and water. It can be dripped into the aquarium or mixed with top off water to help maintain calcium, pH, and alkalinity levels. The ph is very high (around 12.0) and it is used as makeup water to replace calcium used by hard corals and clams to build calcerous skeletons. It is an extremely potent substance and should be used with caution. An overdose can raise alkalinity levels as high as 14 and can be harmful to animals.
Temperature scale used to designate light intensity. For freshwater 6400K-10000K is optimum. For marine 6400K – 20000K is optimum.
Large Polyp Stony Corals - The LPS corals are generally larger calcareous corals. They have much larger fleshy polyps than those of the small polyp stony (SPS) corals. Many LPS corals are quite hardy and can even be fast growing. These stony corals are generally easier to keep in the aquarium than the small polyp stony (SPS) corals. For the most part LPS corals require less intense lighting and a lower flow rate.
The first stage of development after hatching for many fish and invertebrates.
Lateral Line
The lateral line is a line of perforated scales along the flanks of a fish which lead to a pressure-sensitive nervous system. This enables the fish to detect vibrations in the surrounding water caused by other fish and their own reflected vibrations against obstacles.
Live Rock
Calcium carbonate skeletons of corals or other calcareous organisms extracted directly from the ocean, which are colonized by beneficial bacteria and micro and macroscopic marine life that live on and inside it. At high end of the spectrum is rock that has been in the ocean/sea for dozens of years, containing a diversity of lifeforms inside and outside of the rock. This rock contains some marine lifeforms that can’t reproduce in the aquarium, so once they die, they will not be replaced. These creatures will not populate artificial rock put next to them in the aquarium, because they are not mobile AND they don’t reproduce in the aquarium. This true living rock would require it be shipped in water to preserve the greatest diversity of life it has to offer. Shipping water by air is expensive. Most live rock is a step down from this, shipped moist but not in water. Those organisms that cannot handle exposure to air (e.g. many sponges) die. Although there is a large amount of die offs (which is why it has to be cured), this live rock still contains many of the above mentioned marine life that cannot reproduce in the aquarium, and, is still called ‘live rock’. Live rocks are able to perform the denitrification function in the marine system, and they are desirable for this and other reasons. Please see "Artificial Rock" and "Base Rock."
Live Sand
Live sand, or LS is natural reef coral sand that is collected live from the ocean, or non-living coral sand that is cultured to make it live. What makes it live is the microscopic biological bacteria that grows on it, and the many tiny crustaceans and other micro and macro-organisms that reside in it. Live sand can serve as the main base for biological filtration in a saltwater aquarium, while the organisms help consume organic matter in the sand bed. Some of the organisms provide a natural food source for many aquarium inhabitants as well.
Local Fish Store.
Large plant-like algae commonly found in red, green and brown varieties. One of the most common of these is Caulerpa, which produces large green spheres resembling grapes.
Marine Ich
Cryptocaryon irritans - a species of ciliate protozoa that parasitizes marine fish, and is one of the most common causes of disease in marine aquaria. The symptoms and life-cycle are generally similar to those of Ichthyophthirius in freshwater fish, including white spots, on account of which Cryptocaryon is usually called Marine Ich. However, Cryptocaryon can spend a much longer time encysted. Infections can be extremely difficult to treat because of other creatures, such as corals and other invertebrates, which will not survive standard treatments. Ideally fish with Cryptocaryon are quarantined in a hospital tank, where they can be treated with a copper salt or using hyposalinity. The display tank needs to be kept clear of fish for 6-9 weeks, the longer the better. This gives time for the encysted tomonts to release infectious theronts, which die within 24-48 hours when they cannot find a host. Useful treatments of Cryptocaryon irritans are copper solutions, formalin solutions, and quinine based drugs (such as Chloroquine Phosphate and Quinine Diphosphate).
Marine System
More than just the marine display tank, this includes all the places the water goes and lighting. The system includes tank, sump, refugium, skimmer, filters, chiller, UV, generators (e.g., Calcium), ozone makers, the plumbing, lighting, heater, etc.
Marine Velvet
Amyloodinium ocellatum - is a dinoflagellate that infects the gills and skin of both marine and brackish water fishes. The organism may be more closely related to a toxic algae than to the protozoans with which it has been grouped in the past. A similar organism, Oodinium spp., is found in freshwater fish. The disease caused by these organisms has been referred to as "velvet," "rust" and "gold dust disease" - thus, the name Marine Velvet - because of the shiny sheen the parasite imparts to heavily infected fish. Amyloodinium can cause great losses of aquarium fish or fish held in high-density culture systems and has caused serious problems in public aquaria, mariculture systems and home aquaria. If allowed to become established in high-density recirculating systems, it can be difficult to control. Treatment process for an infected fish is similar to the ones of Marine Ich.
Mechanical Filter
These filters act to remove particulate matter from the water in the marine system, including detritus when system circulation is high. They include canister filters, filter socks, filter floss, etc. Anything that captures solids and removes them from the water. Such filters can be problematic if not kept clean.
A broad term used by marine aquarists to describe a purposefully placed solid material into the marine system. It includes things like substrates, absorbents, resins, filter material, etc. Examples include but aren’t limited to: activated carbon, sand, bio-balls, resins that absorb wastes/pollutants, etc.
Metal Halide
A type of light bulb that uses special gases to give off a very bright white light. They give off a spectrum of light very similar to sunlight and are highly recommended for reef aquariums. Metal Halide bulbs require a special ballast unit for operation.
Microalgae or microphytes are microscopic algae, typically found in freshwater and marine systems. They are unicellular species which exist individually, or in chains or groups. Depending on the species, their sizes can range from a few micrometers (µm) to a few hundreds of micrometers.
Microfauna refers to small, mostly microscopic animals, such as protozoa, nematodes, small arthropods, etc. In addition there are other components of the microbiota, such as fungi and bacteria.
Molting (or moulting, also known as sloughing, shedding, or for some species, ecdysis) signifies the manner in which an animal routinely casts off a part of its body (often but not always an outer layer or covering), either at specific times of year, or at specific points in its life-cycle. Please see "Ecdysis".
Nano Reef
A nano reef is a type of marine aquarium that is typically less than 140 litres (30 gallons). The exact limit that distinguishes a nano reef from a regular reef is somewhat ill-defined (some claim that anything less than 180 litres/40 gallons would qualify), but 140 litres (30 gallons) seems to be the generally accepted limit. Nano reefs have become quite popular in recent years among fish keeping hobbyists, primarily because of their smaller size, maintainability, and the possibility of lower costs.
The larval stage, of a crustacean such as Artemia salina or brine shrimp. "Artemia nauplii" are commonly used as a first food for fish.
The cells at the tip of anemones' tentacles which "sting" when touched.
NO3 the final product of nitrification. It is the least toxic of the three waste products, but is still very dangerous at high levels. Nitrate is created by the oxidation of nitrite by nitrobacter bacteria. In a reef tank, nitrate levels should be kept below 10 ppm.
Used to describe the action of a typical biological filter. The chemical reaction done by bacteria converts ammonia waste to nitrites and then nitrites to nitrates.
NO2 the first product of nitrification, after ammonia has been oxidized by nitrosomonas bacteria. Nitrite is still a highly toxic substance, but can be easily converted to the less toxic nitrate by a well established biological filtration.
Nitrogen Cycle
In the broadest sense of the term to marine aquarists, this is the combination of the nitrification process and the denitrification process of all nitrogen wastes. That is, this term represents the chemical process that takes waste nitrogen products (such as in proteins) and changes some of it to ammonia, then changes the ammonia to nitrite, then changes nitrites to nitrates, then changes nitrates to nitrogen gas and other chemicals.
Nitrogen Wastes
Most (solid) wastes in the marine aquarium contain nitrogen. They include ammonia, proteins, certain lipids and fats, ‘organics,’ and amino acids to name a few. They come from things the aquarist puts into the system such a foods, vitamins, and fats, as well as things made in the marine system by marine fish, marine lifeforms, bacteria and other microbial organisms, such as proteins, toxins, ammonia wastes, etc.
Nocturnality is an animal behavior characterized by activity during the night and sleeping during the day. The opposite is diurnality.
Nutrient Export
The removal of excess nutrients via biological, chemical, biochemical and physical processes. In the hobby, this is commonly done by partial water changes, trimming of macroalgae, cleaning of biologial filter media, etc. Please see "Water Change".
Obligate or required - i.e. an obligate parasite is a parasitic organism that cannot live independently of its host, or an obligate aerobe is an organism that cannot survive without oxygen.
Octocorallia (also known as Alcyonaria) is a subclass of Anthozoa comprising ~3,000 species of water-based organisms formed of colonial polyps with 8-fold symmetry. It includes the blue coral, soft corals, sea pens, and gorgonians (sea fans and sea whips) within three orders: Alcyonacea, Helioporacea, and Pennatulacea. These organisms have an internal skeleton secreted by mesoglea and polyps with eight tentacles and eight mesentaries. As with all Cnidarians these organisms have a complex life cycle including a motile phase when they are considered plankton and later characteristic sessile phase. Octocorals resemble the stony corals in general appearance and in the size of their polyps, but lack the distinctive stony skeleton. Also unlike the stony corals, each polyp has only eight tentacles, each of which is feather-like in shape, with numerous side-branches, or pinnules.
Marine life that consumes both animal and plant proteins. These animals have the greatest choices of foods and are Nature’s favorites in that they have a lot of foods to choose from.
This is the word used to describe how the fish controls the amount of salt it has in its body. The environment the fish is in is high in salt content. The marine fish needs to obtain fresh (non-salted water) to carry out internal biological functions. The fish drinks salt water, removes the salt, and sends the salt back into its environment. The fish internal system controls the amount of salt inside the fish. This control is known as osmoregulation and it takes quite a bit of the fish’s energy.
The process by which a liquid passes from an area of low concentration through a semi-permeable membrane to an area of high concentration.
Osmotic Stress
An adverse reaction caused when the salinity of an animal's environment changes drastically.
Oviparous animals are animals that lay eggs, with little or no other embryonic development within the mother. This is the reproductive method of most fish, amphibians, reptiles, all birds, the monotremes, and most insects and arachnids.
An organism that feeds on the tissues of another organism. Parasites are one of the major causes of disease in aquarium fishes. In a parasitic relationship (parasitism ) one species benefits, the other is harmed. Please see "Symbiosis".
Pectoral Fins
These fins are on the sides of the fish located directly behind the gills. They are often used for more precise maneuvering. In a few species they are used for propulsion.
Refers to living in the water of the ocean above the bottom. Pelagic organisms have the ability to swim around or move in some fashion. "Pelagic" is also used to refer (usually) to eggs that are basically at the mercy of the ocean currents.
Pelvic Fins
Paired fins towards the underside of the fish located directly below the gills. Vary in size and shape greatly. Also known as the ventral fins. Not all marine fish have these.
A measure of the concentration of hydrogen and hydroxide ions. The pH of a solution measures how acidic or alkaline it is. pH values range from 0 to 14. A neutral solution has a pH of 7. A pH less than 7 indicates an acidic solution while a pH greater than 7 indicates an alkaline solution. pH can be regulated in the aquarium by using buffering materials. pH and alkalinity can also be maintained by the use of kalkwasser.
A nutrient that can cause uncontrolled growth of algae in the aquarium. It can also be toxic in high concentrations and must be kept to a minimum level in reef aquariums. Phosphate can be easily removed by a number of commercially available filter media.
An organism, typically a plant, obtaining energy from sunlight as its source of energy to convert inorganic materials into organic materials for use in cellular functions such as biosynthesis and respiration. In order to capture light as source of energy, photoautotrophs carry out photosynthesis, converting energy from sunlight, carbon dioxide and water into organic materials. Photoautotrophs provide nutrition for many forms of life. They include the plants, algae and certain protists bacteria.
The duration of an organism's daily exposure to light, considered especially with regard to the effect of the exposure on growth and development. In the hobby, it also refers to the length of time that the aquarium lights remain on, to accommodate certain organisms' requirements to thrive.
Photosynthesis is a process that converts carbon dioxide into organic compounds, especially sugars, using the energy from sunlight. Photosynthesis occurs in plants, algae, and many species of bacteria. Photosynthetic organisms are called photoautotrophs, since they can create their own food. In plants, algae, and cyanobacteria, photosynthesis uses carbon dioxide and water, releasing oxygen as a waste product. Photosynthesis is vital for life on Earth.
Microscopic free-floating aquatic plants, mainly algae. It lives suspended in bodies of water and drifts about.
One that eats other fish.
A general term to describe an organism adapted to feed and survive from eating mostly plankton.
Plankton are any drifting organisms (animals, plants, archaea, or bacteria) that inhabit the pelagic zone of oceans, seas, or bodies of fresh water. They provide a crucial source of food to larger, more familiar aquatic organisms such as fish and cetacea.
A space between the aquarium bottom and substrate, created by supporting the substrate above the bottom using UGF plates or some other support structure. Used to keep Nitrate levels low in a saltwater aquarium. Water and organic waste diffuses down into the plenum where the wastes concentrate. Nitrifying bacteria in the upper levels of the substrate use the oxygen and produce nitrate in the water as it moves down into the space. Denitrifying bacteria living in the oxygen-poor lower levels of the substrate slowly convert Nitrate into harmless nitrogen gas.
The living unit of a coral - A polyp in zoology is one of two forms found in the phylum Cnidaria, the other being the medusa. Polyps are approximately cylindrical in shape and elongated at the axis of the body. In solitary polyps, the aboral end is attached to the substrate by means of a disc-like holdfast called the pedal disc, while in colonies of polyps it is connected to other polyps, either directly or indirectly. The oral end contains the mouth, and is surrounded by a circlet of tentacles.
Prokaryotes are organisms without a cell nucleus, or indeed any other membrane-bound organelles, in most cases unicellular (in rare cases, multicellular).
Protein Skimmer
Used in saltwater tanks to remove organic pollutants from the water before they break down. Also called Foam Fractionator. Produces tiny air bubbles which attract and hold pollutants, which are then deposited into a separate container.
Any memeber of the phylum Protozoa, which comprises of unicellular organisms. Protozoans are a major component of the ecosystem. Protozoa is a subkingdom of microorganisms that are classified generally as unicellular non-fungal eukaryotes.
Quarantine Tank
QT - A separate tank in which newly acquired fish are kept for some time to ensure that they are not suffering from any disease, as well as to acclimate them to captive environment, before they are released into the main aquarium. Also used as a hospital tank to isolate and fully observe an infected fish during treatment, away from the healthy ones.
Red List
The IUCN Red List of Threatened Species - Provides taxonomic, conservation status, and distribution information on taxa that are facing a high risk of global extinction. Also known as the IUCN Red List or Red Data List, founded in 1948, it is the world's most comprehensive inventory of the global conservation status of plant and animal species. The International Union for the Conservation of Nature and Natural Resources (IUCN) is the world's main authority on the conservation status of species. A series of Regional Red Lists are produced by countries or organizations, which assess the risk of extinction to species within a political management unit.
Reef Aquarium
A saltwater aquarium featuring live corals to simulate a coral reef with a selection of Invert inhabitants. It may or may not include reef fish. Such aquariums place extremely high demands on lighting and water quality.
Reef Safe
Reef safe is a distinction used in the saltwater aquarium hobby to indicate that a fish or invertebrate is safe to add to a reef aquarium. Saltwater fish known to tear up corals, consume fish, harm other sessile invertebrates, and otherwise destroy other tank inhabitants are considered NOT reef safe.
An instrument used to measure salinity by refraction, the amount light deflects from a straight line through a medium.
The part of the marine system where the aquarist has set up to contain marine lifeforms that wouldn’t survive in the display tank. This is often another tank in the marine system where macro algae, a deep sand bed, mud, and/or other marine organisms, such as copepods, are cultured or maintained.
RO - Reverse Osmosis
Reverse osmosis (RO) is a filtration method that removes many types of large molecules and ions from solutions by applying pressure to the solution when it is on one side of a selective membrane. The result is that the solute is retained on the pressurized side of the membrane and the pure solvent is allowed to pass to the other side. In the hobby, it is the process for filtering water for use in an aquarium. This process can produce very pure water, but it is slow and can only filter small amounts at a time.
The amount of salt in the water and is measured in parts per thousand (ppt). Natural seawater has a salinity of about 35 ppt.
A group of one kind of fish oriented together in a synchronized fashion, with uniform distance between individual fishes, traveling at the same speed and/or oriented in the same direction and position. Please also see "Shoal".
Sessile means the organism is attached to the substrate at the bottom of the ocean and therefore cannot move around.
Sexual Dimorphism
Sexual dimorphism is the systematic difference in form between individuals of different sex in the same species. Examples include colour (specifically referred to as sexual dichromatism), size, and the presence or absence of parts of the body used in courtship displays or fights, such as ornamental feathers, horns, antlers, or tusks.
Sexual Reproduction
Reproduction involving the paired union of special cells (gametes) from two individuals (parents). Sexual reproduction is one of the two major ways, along with asexual reproduction, that plants and animals create offspring and thus propagate the species.
A group of fish loosely gathered together but with variable distance between individuals and moving in various directions and/or oriented in various positions. Fish that shoal together will often school when on the move or in response to a threat. Please also see "School".
Silicone Sealant
A transparent, rubbery adhesive used in aquariums to bond glasses and plug leaks. It can also be used in reef tanks to attach rock and coral formations.
An arrangement whereby water is induced to flow naturally from an upper level to a lower level through a pipe or hose which spans an intermediate level that is higher than either.
Slime Coat
The continuously produced mucous envelope which covers the scales of a fish and makes it feel ‘slippery.’ Its purpose is to act as a barrier against disease-causing organisms, to act as a buffer in the internal/external gas exchange systems of the fish, and to save energy by reducing friction with the water when swimming. When a fish is subjected to Stress the Slime Coat becomes thinner.
SG - Specific Gravity
A measure of density in comparison to pure water at a specific temperature. In this context, it is used as a measure of salinity. The average specific gravity of an ideal marine tank ranges from 1.020 to 1.025. Please see "Salinity" and "Osmotic Stress".
Spirulina is a microscopic blue-green alga in the shape of a spiral coil, living both in sea and fresh water. Spirulina is the common name for human and animal food supplements produced primarily from two species of cyanobacteria: Arthrospira platensis, and Arthrospira maxima. Spirulina can be fed to both saltwater and freshwater fish.
Sponge Filter
A type of filter that provides both mechanical and biological filtration. As water passes through the sponge, particles are removed. Bacteria growing on the surface of the sponge also remove toxic substances from the water.
The substrate of an aquarium refers to the material used on the tank bottom. It can affect water chemistry, filtration, and the well-being of the aquarium's inhabitants, and is also an important part of the aquarium's aesthetic appeal.
In the designing of a marine system, a sump holds water coming to it by gravity from the display tank overflow(s). The sump may have inside of it several pieces of equipment to make more room for lifeforms in the display tank. Such things that may be found/put inside the sump include a skimmer, heater, chiller, mechanical filter, biological filter, etc. Water in the sump is pumped back into the display tank where it forces more water into the overflow(s) sending more water back to the sump. This cycle continues in this manner unless/until the return pump stops. Then all the excess display water goes into the overflow and then into the sump. The volume of the sump must comfortably hold this volume of water, plus any volume displaced by the equipment put into it.
Sweeper Tentacles
A coral tentacle or polyp that has an increased number of nematocysts and elongates in order to attack or 'sting' neighboring corals and sessile invertebrates.
Swim Bladder
An internal air sac which can contain more or less air according to the needs of the fish at the time. More air helps the fish become more buoyant, while less air allows the fish to swim down to deeper levels. Also called Air bladder. Serves to keep fish properly oriented in the water. Also creates and amplifies sounds.
Swim Bladder Disease
A condition in which the Swim Bladder fails to function normally. Causes vary. Symptoms include an inability to maintain normal upright position, or difficulty swimming down to lower levels of the water column.
The term symbiosis commonly describes close and often long-term interactions between different biological species. The term was first used in 1879 by the German mycologist Heinrich Anton de Bary, who defined it as "the living together of unlike organisms." The definition of symbiosis is in flux, and the term has been applied to a wide range of biological interactions. The symbiotic relationship may be categorized as mutualistic, commensal, or parasitic in nature. Some symbiotic relationships are obligate, meaning that both symbionts entirely depend on each other for survival. The most commonly witnessed symbiosis in the marine home aquaria are the anemonefish with the anemones, and the shrimps gobies with the pistol shrimps.
The classification of organisms in an ordered system that indicates natural relationships.
Trace Elements
Chemical elements which are required, usually in tiny quantities, for healthy growth of fish, plants, and invertebrates. These elements are normally supplied by regular water changes or in salt mixes for marine aquariums, but in certain cases it may be necessary to supplement this.
Trickle Filter
A filtration system where water is dripped over some medium that is exposed to the air. This increases the amount of oxygen available to the bacteria, promoting Nitrification.
The rate at which the total volume of the tank water is processed through the filter system. Please see "Flow Rate" for further information.
UV - Ultraviolet Sterilizer
A UV Sterilizer is a filtration device that uses ultraviolet light to remove unwanted free floating microscopic water borne bacteria, parasitic, fungal, viral, algae, and other unfriendly pathogens out of aquarium water by exposing it to high intensity ultra-violet (UV) light. UV light has the ability to effect the function of living cells by altering the structure of the cells nuclear material, or DNA, leaving the organisms exposed to the light severely impaired at reproducing or dead.
UGF – Under Gravel Filter
Perforated plates rest on the aquarium bottom and support the gravel substrate. Using lift tubes and power heads, water is pulled down through the gravel, up into the tube, and returned to the water column. UGF provides both mechanical and biological filtration.
The uro-genital opening of fish, located between the anus and the anal fin. Also referred to as the genital papilla.
Ventral Fins
Pelvic Fins. The most posterior (toward the rear of the fish) set of paired fins on the underside of the fish. Please see "Pelvic Fins".
A special type of valve that produces air bubbles by drawing air into a stream of water flowing under pressure. Venturi valves are used on a variety of protein skimmers.
Very High Output (VHO) lights are specially designed fluorescent lights that give off a much higher intensity light than regular fluorescent bulbs. This makes them much more effective as light sources for reef systems, since many corals require strong light. As with all fluorescent lights, VHOs require a ballast unit for operation.
Vodka Dosing
Vodka dosing can be used to maintain a reef tank successfully, reducing nitrate and phosphate levels to improve water quality. This method reduces these nutrients by stimulation and promotion of bacterial growth through the addition of vodka. Though the underlying mechanism and actual bacteria populations are unknown the results are impressive for their ability to both rid the system of excess nitrates and phosphates. For more information about "Vodka Dosing", please click here.
Water Change
In the marine aquarium hobby, it is the process of replacing a portion of aquarium water with a fresh saltwater mix. This is one way of exporting nutrients from the tank to reduce nitrate and phosphate.
Water Column
The water in the aquarium from the top of the substrate to the surface of the water.
Water Conditioner
A chemical product formulated to treat tap water to make it safe for aquarium use. Water conditioners usually eliminate Chlorine and Chloramines but may also contain ingredients that bind heavy metals, detoxify nitrogen compounds, fortify the Slime Coat of fish, and have other beneficial effects.
Water Parameters
The readings for measurable factors of water in an aquarium. Basic aquarium water parameters include Ammonium, Nitrite, Nitrate, pH, General Hardness, Salinity and/or Specific Gravity, Temperature and Buffering Capacity.
Wet/dry Filter
A biological filtration system that is exposed to the air to aid nitrification. This system typically consists of a large box that is placed underneath the aquarium. Water passes down into the filter over a filtration medium where bacteria remove toxins. The water is then pumped back up into the tank. A sponge or other mechanical filtration medium may also be used in a wet/dry filter.
Wild Caught
Wild Caught, Wild Collected or WC - Animals that are taken from native habitat (directly from the wild) and introduced to the captive environment. The captive environment includes wildlife preserves, zoos, conservation facilities, commercial breeding farms, and in the case of tropical fish, the home aquaria. Bringing new species into culture, keeping them alive and propagating them in captivity, can safeguard endangered animals from going extinct. Please see "Captive Bred" and "Captive Environment".
Zoology is the branch of biology that focuses on the structure, function, behavior, and evolution of animals.
Small, usually microscopic animals; includes tiny waterborne crustaceans and fish larvae, also includes corals, rotifers, sea anemones, and jellyfish.
(zo-zan-thel-ee) - Zooxanthellae algae are tiny plants called dinoflagellates (single-celled microscopic organisms which belong to the Protista kingdom) that live symbiotically with corals, tridacnid clams, and some sponges. The algae provides food for the host and in return gets the nitrogen, phosphorous, and carbon dioxide it needs to grow. The scientific name is Symbiodinium spp.
References / Sources:
About Saltwater Aquariums - (
Age of Aquariums - (
Animal World - (
Biology Online - (
Encyclopædia Britannica - (
The Free Dictionary - (
Reefland - (
Reekeeping - (
Science Daily - (
Sea and Sky - (
Seahorse.Org - (
Saltwater Aquarium Guide - (
Wikipedia - (