Fish Keeping

Contents

Types of fishkeeping

The origins of fishkeeping

Aquarium maintenance

Water conditions

Nitrogen cycle

The process

Maintaining the Nitrogen cycle

Biological loading

Calculating aquarium capacity

Factors affecting capacity

Fishkeeping industry

Fish breeding

Animal welfare

Fish modification

Conservation

Fish capture

Captive breeding and aquaculture

Invasive species

Nomenclature

Characteristics

Examples

Gallery

Garden pond.

Garden pond.

Fish Keeping

Fishkeeping is a popular hobby concerned with keeping fish in the home aquarium or garden pond.

A naturally aquascaped freshwater aquarium.

A naturally aquascaped freshwater aquarium.

Contents

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    * 1 Types of fishkeeping

    * 2 The origins of fishkeeping

    * 3 Aquarium maintenance

          o 3.1 Water conditions

          o 3.2 Nitrogen cycle

                + 3.2.1 The process

                + 3.2.2 Maintaining the Nitrogen cycle

          o 3.3 Biological loading

                + 3.3.1 Calculating aquarium capacity

                + 3.3.2 Factors affecting capacity

    * 4 Fishkeeping industry

    * 5 Fish breeding

    * 6 Animal welfare

    * 7 Fish modification

    * 8 Conservation

          o 8.1 Fish capture

          o 8.2 Captive breeding and aquaculture

          o 8.3 Invasive species

    * 9 References

    * 10 External links

    * 11 Further reading

 

 Types of fishkeeping

 

The hobby can be broadly divided into three specific disciplines, Portsmouth Tropical Fish freshwater, Portsmouth Tropical Fish brackish, Portsmouth Tropical Fish and marine (also called saltwater) fishkeeping. Freshwater fishkeeping is by far the most popular branch of the hobby, Portsmouth Tropical Fish with even small pet stores often selling a variety of freshwater fish, Portsmouth Tropical Fish such as goldfish, Portsmouth Tropical Fish guppies, Portsmouth Tropical Fish and angelfish. While most freshwater aquaria are set up as community tanks containing a variety of peaceful species, Portsmouth Tropical Fish many aquarists keep single-species aquaria with a view to breeding. Livebearing fish such as mollies and guppies are among the species that are most easily raised in captivity, Portsmouth Tropical Fish but aquarists also regularly breed numerous other species, Portsmouth Tropical Fish including many types of cichlid, Portsmouth Tropical Fish catfish, Portsmouth Tropical Fish characin, Portsmouth Tropical Fish and killifish.

 

Marine aquaria are generally more difficult to maintain and the livestock is significantly more expensive, Portsmouth Tropical Fish and as a result this branch of the hobby tends to attract more experienced fishkeepers. However, Portsmouth Tropical Fish marine aquaria can be exceedingly beautiful, Portsmouth Tropical Fish due to the attractive colours and shapes of the corals and coral reef fish kept in them. Temperate zone marine fish are not as commonly kept in home aquaria, Portsmouth Tropical Fish primarily because they do not do well at room temperature. An aquarium containing these coldwater species usually needs to be either located in a cool room (such as an unheated basement) or else chilled using a refrigeration device known as a 'chiller'.

 

Brackish water aquaria combine elements of both marine and freshwater fishkeeping, Portsmouth Tropical Fish reflecting the fact that these aquaria contain water with a salinity in between that of freshwater and seawater. Fish kept in brackish water aquaria come from habitats with varying salinity, Portsmouth Tropical Fish such as mangroves and estuaries and do not do well if permanently kept in freshwater aquaria. Although brackish water aquaria are not overly familiar to newcomers to the hobby, Portsmouth Tropical Fish a surprising number of species prefer brackish water conditions, Portsmouth Tropical Fish including the mollies, Portsmouth Tropical Fish many gobies, Portsmouth Tropical Fish some pufferfish, Portsmouth Tropical Fish monos, Portsmouth Tropical Fish scats, Portsmouth Tropical Fish and virtually all the freshwater soles.

 

Fishkeepers are often known as aquarists, Portsmouth Tropical Fish since many of them are not solely interested in keeping fish. Many fishkeepers create freshwater aquaria where the focus is on the aquatic plants rather than on the fish. This is known as the 'Dutch Aquarium' in some circles, Portsmouth Tropical Fish in reference to the pioneering work carried out by European aquarists in designing these sorts of aquaria. In recent years, Portsmouth Tropical Fish one of the most active advocates of the heavily planted aquarium is the Japanese aquarist Takashi Amano. Marine aquarists often attempt to recreate the coral reef in their aquaria using large quantities of living rock, Portsmouth Tropical Fish porous calcareous rocks encrusted with algae, Portsmouth Tropical Fish sponges, Portsmouth Tropical Fish worms, Portsmouth Tropical Fish and other small marine organisms. Larger corals as well as shrimps, Portsmouth Tropical Fish crabs, Portsmouth Tropical Fish echinoderms, Portsmouth Tropical Fish and mollusks are added later on, Portsmouth Tropical Fish once the aquarium has matured, Portsmouth Tropical Fish as well as a variety of small fish. Such aquaria are sometimes called 'reef tanks'.

 

Garden ponds are in some ways similar to freshwater aquaria, Portsmouth Tropical Fish but are usually much larger and exposed to the ambient climatic conditions. In the tropics, Portsmouth Tropical Fish tropical fish can be kept in garden ponds, Portsmouth Tropical Fish but in the cooler regions temperate zone species such as goldfish, Portsmouth Tropical Fish koi, Portsmouth Tropical Fish and orfe are kept instead.

 

 The origins of fishkeeping

Koi have been kept in decorative ponds for centuries in China and Japan.

Koi have been kept in decorative ponds for centuries in China and Japan.

 

The keeping of fish in confined or artificial environments is a practice with deep roots in history.

 

Fish have been raised as food in pools and ponds for thousands of years. In Medieval Europe, Portsmouth Tropical Fish carp pools were a standard feature of estates and monasteries, Portsmouth Tropical Fish providing an alternative to meat on feast days when meat could not be eaten for religious reasons. Similarly, Portsmouth Tropical Fish throughout Asia there is a long history of stocking rice paddies with freshwater fish suitable for eating, Portsmouth Tropical Fish including various types of catfish and cyprinid. Ancient Sumerians were known to keep wild-caught fish in ponds, Portsmouth Tropical Fish before preparing them for meals. Particularly brightly coloured or tame specimens of fish in these pools have sometimes been valued as pets rather than food, Portsmouth Tropical Fish and some of these have given rise to completely domesticated varieties, Portsmouth Tropical Fish most notably the goldfish and the koi carp, Portsmouth Tropical Fish which have their origins in China and Japan respectively. Selective breeding of carp into today's popular koi and goldfish is believed to have begun over 2,000 years ago. Depictions of the sacred fish of Oxyrhynchus kept in captivity in rectangular temple pools have been found in ancient Egyptian art. Many other cultures also have a history of keeping fish for both functional and decorative purposes. The Chinese brought goldfish indoors during the Song dynasty to enjoy them in large ceramic vessels.

 

Marine fish have been similarly valued for centuries, Portsmouth Tropical Fish and many wealthy Romans kept lampreys and other fish in salt water pools. Cicero reports that the advocate Quintus Hortensius wept when a favoured specimen died, Portsmouth Tropical Fish while Tertullian reports that Asinius Celer paid 8000 sesterces for a particularly fine mullet.1 Cicero, Portsmouth Tropical Fish rather cynically, Portsmouth Tropical Fish referred to these ancient fishkeepers as the Piscinarii, Portsmouth Tropical Fish the "fish-pond owners" or "fish breeders", Portsmouth Tropical Fish for example when saying that ...the rich (I mean your friends the fish-breeders) did not disguise their jealousy of me.234

 

 Aquarium maintenance

A 335,000 U.S. gallon (1.3 million litre) aquarium at the Monterey Bay Aquarium in California displaying a simulated kelp forest ecosystem

A 335,000 U.S. gallon (1.3 million litre) aquarium at the Monterey Bay Aquarium in California displaying a simulated kelp forest ecosystem

 

Ideal aquarium ecology reproduces the balance found in nature in the closed system of an aquarium. In practice it is virtually impossible to maintain a perfect balance. As an example, Portsmouth Tropical Fish a balanced predator-prey relationship is nearly impossible to maintain in even the largest of aquaria. Typically an aquarium keeper must take steps to maintain balance in the small ecosystem contained in his aquarium.

 

Approximate balance is facilitated by large volumes of water. Any event that perturbs the system pushes an aquarium away from equilibrium; the more water that is contained in a tank, Portsmouth Tropical Fish the easier such a systemic shock is to absorb, Portsmouth Tropical Fish as the effects of that event are diluted. For example, Portsmouth Tropical Fish the death of the only fish in a three U.S. gallon tank (11 L) causes dramatic changes in the system, Portsmouth Tropical Fish while the death of that same fish in a 100 U.S. gallon (400 L) tank with many other fish in it represents only a minor change in the balance of the tank. For this reason, Portsmouth Tropical Fish hobbyists often favor larger tanks when possible, Portsmouth Tropical Fish as they are more stable systems requiring less intensive attention to the maintenance of equilibrium.

 

There are a variety of nutrient cycles that are important in the aquarium. Dissolved oxygen enters the system at the surface water-air interface or through the actions of an air pump. Carbon dioxide escapes the system into the air. The phosphate cycle is an important, Portsmouth Tropical Fish although often overlooked, Portsmouth Tropical Fish nutrient cycle. Sulfur, Portsmouth Tropical Fish iron, Portsmouth Tropical Fish and micronutrients also cycle through the system, Portsmouth Tropical Fish entering as food and exiting as waste. Appropriate handling of the nitrogen cycle, Portsmouth Tropical Fish along with supplying an adequately balanced food supply and considered biological loading, Portsmouth Tropical Fish is usually enough to keep these other nutrient cycles in approximate equilibrium.

 

 Water conditions

 

The solute content of water is perhaps the most important aspect of water conditions, Portsmouth Tropical Fish as total dissolved solids and other constituents can dramatically impact basic water chemistry, Portsmouth Tropical Fish and therefore how organisms are able to interact with their environment. Salt content, Portsmouth Tropical Fish or salinity, Portsmouth Tropical Fish is the most basic classification of water conditions. An aquarium may have fresh water (salinity below 0.5 PPT), Portsmouth Tropical Fish simulating a lake or river environment; brackish water (a salt level of 0.5 to 30 PPT), Portsmouth Tropical Fish simulating environments lying between fresh and salt, Portsmouth Tropical Fish such as estuaries; and salt water or sea water (a salt level of 30 to 40 PPT), Portsmouth Tropical Fish simulating an ocean or sea environment. Rarely, Portsmouth Tropical Fish even higher salt concentrations are maintained in specialized tanks for raising brine organisms.

 

Several other water characteristics result from dissolved contents of the water, Portsmouth Tropical Fish and are important to the proper simulation of natural environments. The pH of the water is a measure of the degree to which it is alkaline or acidic. Saltwater is typically alkaline, Portsmouth Tropical Fish while the pH of fresh water varies more. Hardness measures overall dissolved mineral content; hard or soft water may be preferred. Hard water is usually alkaline, Portsmouth Tropical Fish while soft water is usually neutral to acidic.Dissolved organic content and dissolved gases content are also important factors.

 

Home aquarists typically use modified tap water supplied through their local water supply network to fill their tanks. Because of the chlorine used to disinfect drinking water supplies for human consumption, Portsmouth Tropical Fish straight tap water cannot be used. In the past, Portsmouth Tropical Fish it was possible to "condition" the water by simply letting the water stand for a day or two, Portsmouth Tropical Fish which allows the chlorine time to dissipate.However, Portsmouth Tropical Fish chloramine is now used more often as it is much stabler and will not leave the water as readily. Additives formulated to remove chlorine or chloramine are often all that is needed to make the water ready for aquarium use. Brackish or saltwater aquaria require the addition of a mixture of salts and other minerals, Portsmouth Tropical Fish which are commercially available for this purpose.

 

More sophisticated aquarists may make other modifications to their base water source to modify the water's alkalinity, Portsmouth Tropical Fish hardness, Portsmouth Tropical Fish or dissolved content of organics and gases, Portsmouth Tropical Fish before adding it to their aquaria. This can be accomplished by a range of different additives, Portsmouth Tropical Fish such as sodium bicarbonate to raise pH.Some aquarists will even filter or purify their water prior to adding it to their aquarium. There are two processes used for that: deionization or reverse osmosis. In contrast, Portsmouth Tropical Fish public aquaria with large water needs often locate themselves near a natural water source (such as a river, Portsmouth Tropical Fish lake, Portsmouth Tropical Fish or ocean) in order to have easy access to a large volume of water that does not require much further treatment.

 

The temperature of the water forms the basis of one of the two most basic aquarium classifications: tropical vs. cold water. Most fish and plant species tolerate only a limited range of water temperatures: Tropical or warm water aquaria, Portsmouth Tropical Fish with an average temperature of about 25 °C (77 °F), Portsmouth Tropical Fish are much more common, Portsmouth Tropical Fish and tropical fish are among the most popular aquarium denizens. Cold water aquaria are those with temperatures below what would be considered tropical; a variety of fish are better suited to this cooler environment. More importantly than the temperature range itself is the consistency in temperature; most organisms are not accustomed to sudden changes in temperatures, Portsmouth Tropical Fish which could cause shock and lead to disease.Water temperature can be regulated with a combined thermometer and heater unit (or, Portsmouth Tropical Fish more rarely, Portsmouth Tropical Fish with a cooling unit).

 

Water movement can also be important in accurately simulating a natural ecosystem. Aquarists may prefer anything from still water up to swift simulated currents in an aquarium, Portsmouth Tropical Fish depending on the conditions best suited for the aquarium's inhabitants. Water movement can be controlled through the use of aeration from air pumps, Portsmouth Tropical Fish powerheads, Portsmouth Tropical Fish and careful design of internal water flow (such as location of filtration system points of inflow and outflow).

 

 Nitrogen cycle

The nitrogen cycle in an aquarium.

The nitrogen cycle in an aquarium.

 

Of primary concern to the aquarist is management of the biological waste produced by an aquarium's inhabitants. Fish, Portsmouth Tropical Fish invertebrates, Portsmouth Tropical Fish fungi, Portsmouth Tropical Fish and some bacteria excrete nitrogen waste in the form of ammonia (which may convert to ammonium, Portsmouth Tropical Fish depending on water chemistry) which must then pass through the nitrogen cycle. Ammonia is also produced through the decomposition of plant and animal matter, Portsmouth Tropical Fish including fecal matter and other detritus. Nitrogen waste products become toxic to fish and other aquarium inhabitants at high concentrations.5

 

 The process

 

A well-balanced tank contains organisms that are able to metabolize the waste products of other aquarium residents. The nitrogen waste produced in a tank is metabolized in aquaria by a type of bacteria known as nitrifiers (genus Nitrosomonas). Nitrifying bacteria capture ammonia from the water and metabolize it to produce nitrite. Nitrite is also highly toxic to fish in high concentrations. Another type of bacteria, Portsmouth Tropical Fish genus Nitrospira, Portsmouth Tropical Fish converts nitrite into nitrate, Portsmouth Tropical Fish a less toxic substance to aquarium inhabitants. (Nitrobacter bacteria were previously believed to fill this role, Portsmouth Tropical Fish and continue to be found in commercially available products sold as kits to "jump start" the nitrogen cycle in an aquarium. While biologically they could theoretically fill the same niche as Nitrospira, Portsmouth Tropical Fish it has recently been found that Nitrobacter are not present in detectable levels in established aquaria, Portsmouth Tropical Fish while Nitrospira are plentiful.) This process is known in the aquarium hobby as the nitrogen cycle.

 

In addition to bacteria, Portsmouth Tropical Fish aquatic plants also eliminate nitrogen waste by metabolizing ammonia and nitrate. When plants metabolize nitrogen compounds, Portsmouth Tropical Fish they remove nitrogen from the water by using it to build biomass. However, Portsmouth Tropical Fish this is only temporary, Portsmouth Tropical Fish as the plants release nitrogen back into the water when older leaves die off and decompose.

 

 Maintaining the Nitrogen cycle

 

Although informally called the nitrogen cycle by hobbyists, Portsmouth Tropical Fish it is in fact only a portion of a true cycle: nitrogen must be added to the system (usually through food provided to the tank inhabitants), Portsmouth Tropical Fish and nitrates accumulate in the water at the end of the process, Portsmouth Tropical Fish or become bound in the biomass of plants. This accumulation of nitrates in home aquaria requires the aquarium keeper to remove water that is high in nitrates, Portsmouth Tropical Fish or remove plants which have grown from the nitrates.

 

Aquaria kept by hobbyists often do not have the requisite populations of bacteria needed to detoxify nitrogen waste from tank inhabitants. This problem is most often addressed through two filtration solutions: Activated carbon filters absorb nitrogen compounds and other toxins from the water, Portsmouth Tropical Fish while biological filters provide a medium specially designed for colonization by the desired nitrifying bacteria. Activated carbon and other substances, Portsmouth Tropical Fish such as ammonia absorbing resines, Portsmouth Tropical Fish will stop working when their pores get full, Portsmouth Tropical Fish so these components have to be replaced with fresh stocks constantly.

 

New aquaria often have problems associated with the nitrogen cycle due to insufficient number of beneficial bacteria, Portsmouth Tropical Fish known as the "New Tank Syndrome". Therefore new tanks have to be "matured" before stocking them with fish. There are two basic approaches to this: the fishless cycle and the silent cycle.

 

No fish are kept in a tank undergoing a fishless cycle. Instead, Portsmouth Tropical Fish small amounts of ammonia are added to the tank to feed the bacteria being cultured. During this process, Portsmouth Tropical Fish ammonia, Portsmouth Tropical Fish nitrite, Portsmouth Tropical Fish and nitrate levels are tested to monitor progress. The silent cycle is basically nothing more than densely stocking the aquarium with fast-growing aquatic plants and relying on them to consume the nitrogen, Portsmouth Tropical Fish allowing the necessary bacterial populations time to develop. According to anecdotal reports of aquarists specializing in planted tanks, Portsmouth Tropical Fish the plants can consume nitrogenous waste so efficiently that the spikes in ammonia and nitrite levels normally seen in more traditional cycling methods are greatly reduced, Portsmouth Tropical Fish if they are detectable at all.

 

The largest bacterial populations are found in the filter; efficient filtration is vital. Sometimes, Portsmouth Tropical Fish a vigorous cleaning of the filter is enough to seriously disturb the biological balance of an aquarium. Therefore, Portsmouth Tropical Fish it is recommended to rinse mechanical filters in an outside bucket of aquarium water to dislodge organic materials that contribute to nitrate problems, Portsmouth Tropical Fish while preserving bacteria populations. Another safe practice consists of cleaning only one half of the filter media every time the filter or filters are serviced.

 

 Biological loading

19 Litre Aquarium, Portsmouth Tropical Fish seems to be overcrowded

19 Litre Aquarium, Portsmouth Tropical Fish seems to be overcrowded

 

Biological loading is a measure of the burden placed on the aquarium ecosystem by its living inhabitants. High biological loading in an aquarium represents a more complicated tank ecology, Portsmouth Tropical Fish which in turn means that equilibrium is easier to perturb. In addition, Portsmouth Tropical Fish there are several fundamental constraints on biological loading based on the size of an aquarium. The surface area of water exposed to air limits dissolved oxygen intake by the tank. The capacity of nitrifying bacteria is limited by the physical space they have available to colonize. Physically, Portsmouth Tropical Fish only a limited size and number of plants and animals can be fit into an aquarium while still providing room for movement.

 

 Calculating aquarium capacity

 

An aquarium can only support a certain number of fish. Limiting factors include the availability of oxygen in the water and the rate at which the filter can process waste. Aquarists have developed a number of rules of thumb to allow them to estimate the number of fishes that can be kept in a given aquarium; the examples below are for small freshwater fish, Portsmouth Tropical Fish larger freshwater fishes and most marine fishes need much more generous allowances.

 

    * 3 cm of fish length per 4 litres of water (i.e., Portsmouth Tropical Fish a 6 cm-long fish would need about 8 litres of water).6

    * 1 cm of fish length per 30 square centimetres of surface area.7

    * 1 inch of fish length per gallon of water.6

    * 1 inch of fish length per 3 square inches of surface area.7

 

Experienced aquarists warn against applying these rules too strictly because they do not consider other important issues such as growth rate, Portsmouth Tropical Fish activity level, Portsmouth Tropical Fish social behaviour, Portsmouth Tropical Fish and so on.8 To some degree, Portsmouth Tropical Fish establishing the maximum loading capacity of an aquarium depends upon slowly adding fish and monitoring water quality over time, Portsmouth Tropical Fish essentially a trial and error approach.

 

 Factors affecting capacity

 

Though many conventional methods of calculating the capacity of aquarium is based on volume and pure length of fish, Portsmouth Tropical Fish there are other variables. One variable is differences between fish. Smaller fish consume more oxygen per gram of body weight than larger fish. Labyrinth fish, Portsmouth Tropical Fish having the capability to breathe atmospheric oxygen, Portsmouth Tropical Fish are noted for not needing as much surface area (however, Portsmouth Tropical Fish some of these fish are territorial, Portsmouth Tropical Fish and may not appreciate crowding). Barbs also require more surface area than tetras of comparable size.5

 

Oxygen exchange at the surface is an important constraint, Portsmouth Tropical Fish and thus the surface area of the aquarium. Some aquarists go so far as to say that a deeper aquarium with more volume holds no more fish than a shallower aquarium of the same surface area. The capacity can be improved by surface movement and water circulation such as through aeration, Portsmouth Tropical Fish which not only improves oxygen exchange, Portsmouth Tropical Fish but also the decomposition of waste materials.5

 

The presence of waste materials presents itself as a variable as well. Decomposition is an oxygen-consuming process, Portsmouth Tropical Fish therefore the more decaying matter there is, Portsmouth Tropical Fish the less oxygen as well. Oxygen dissolves less readily in warmer water; this is a double-edged sword as warmer temperatures make more active fish, Portsmouth Tropical Fish which in turn consume even more oxygen. Stress due to temperature changes is especially obvious in coldwater aquaria where the temperature may swing from low temperatures to high temperatures on hotter days.5

 

 Fishkeeping industry

 

Worldwide, Portsmouth Tropical Fish the fishkeeping hobby is a multi-million dollar industry, Portsmouth Tropical Fish and the United States is considered the largest market in the world, Portsmouth Tropical Fish followed by Europe and Japan. In 1994, Portsmouth Tropical Fish 56% of U.S. households had pets, Portsmouth Tropical Fish and 10.6% owned ornamental freshwater or saltwater fish, Portsmouth Tropical Fish with an average of 8.8 fish per household. In 1993, Portsmouth Tropical Fish the retail value of the fish hobby in the United States was $910 million.

 

From 1989 to 1992, Portsmouth Tropical Fish almost 79% of all U.S. ornamental fish imports arrived from Southeast Asia and Japan. Singapore, Portsmouth Tropical Fish Thailand, Portsmouth Tropical Fish the Philippines, Portsmouth Tropical Fish Hong Kong, Portsmouth Tropical Fish and Indonesia were the top five exporting nations. South America was the second largest exporting region, Portsmouth Tropical Fish accounting for 14% of the total annual value. Colombia, Portsmouth Tropical Fish Brazil, Portsmouth Tropical Fish and Peru were the major suppliers. The remaining 7% of ornamental fish imports came from other regions of the world.

 

Approximately 201 million fish worth $44.7 million were imported into the United States in 1992. These fish comprised 1,539 different species; 730 freshwater species, Portsmouth Tropical Fish and 809 saltwater species. The freshwater fish accounted for approximately 96% of the total volume and 80% of the total import value. Of the total of all trade, Portsmouth Tropical Fish only 32 species had import values over $10,000. These top species were all of freshwater origin and accounted for 58% of the total imported value of the fish. The top imported species are the guppy, Portsmouth Tropical Fish neon tetra, Portsmouth Tropical Fish platy, Portsmouth Tropical Fish betta, Portsmouth Tropical Fish Chinese algae eater, Portsmouth Tropical Fish and goldfish.

 

Several large companies are focused primarily or extensively on supplying the fishkeeping hobby, Portsmouth Tropical Fish producing products such as fish food, Portsmouth Tropical Fish medicine, Portsmouth Tropical Fish and aquarium hardware. Among the largest of these are Eheim, Portsmouth Tropical Fish Tetra, Portsmouth Tropical Fish Sera, Portsmouth Tropical Fish all based in Germany; Hikari, Portsmouth Tropical Fish a Japanese company; Fluval, Portsmouth Tropical Fish part of the Canadian Rolf C. Hagen group; Interpet, Portsmouth Tropical Fish a British company that also owns the Red Sea brand; and the American company Aquarian, Portsmouth Tropical Fish owned by Mars, Portsmouth Tropical Fish Incorporated but usually trading under the Waltham pet foods brand.

 

Historically, Portsmouth Tropical Fish fish and plants for the first modern aquaria were gathered from the wild and transported (usually by ship) to European and American ports. During the early 20th century many species of small colorful tropical fish were caught and exported from Manaus, Portsmouth Tropical Fish Brazil; Bangkok, Portsmouth Tropical Fish Thailand; Jakarta, Portsmouth Tropical Fish Indonesia; the Netherlands Antilles; Kolkata, Portsmouth Tropical Fish India; and other tropical ports. Collection of fish, Portsmouth Tropical Fish plants, Portsmouth Tropical Fish and invertebrates from the wild for supply to the aquarium trade continues today at locations around the world. In many developing countries, Portsmouth Tropical Fish local villagers collect specimens for the aquarium trade as their prime means of income. It remains an important source for many species that have not been successfully bred in captivity, Portsmouth Tropical Fish and continues to introduce new species to enthusiastic aquarists.

 

 Fish breeding

A Discus (Symphysodon spp.) guarding its eggs.

A Discus (Symphysodon spp.) guarding its eggs.

 

Fish breeding is a challenge that many aquarists find attractive. While some species reproduce freely in community tanks, Portsmouth Tropical Fish most require special conditions, Portsmouth Tropical Fish known as spawning triggers before they will breed. The majority of fish lay eggs, Portsmouth Tropical Fish known as spawning, Portsmouth Tropical Fish and the juvenile fish that emerge are very small and need tiny live foods or their substitutes to survive. A fair number of popular aquarium fish are livebearers, Portsmouth Tropical Fish and these fish produce a small number of relatively large offspring, Portsmouth Tropical Fish and these will usually take ground flake food straight away (see article on live-bearing aquarium fish).

 

 Animal welfare

 

At its best, Portsmouth Tropical Fish a properly maintained aquarium allows the fish to socialise with their own kind and in many cases breed successfully. This is in marked contrast to the conditions enjoyed by larger animals like cats and dogs, Portsmouth Tropical Fish which are often kept alone and neutered, Portsmouth Tropical Fish and thus unable to experience anything like a natural lifestyle. However, Portsmouth Tropical Fish in many cases fish are maintained in the wrong conditions and therefore live short lives and never breed. Inexperienced aquarists often attempt to keep too many fish in their tanks, Portsmouth Tropical Fish or introduce too many fish into an immature aquarium, Portsmouth Tropical Fish with the result that large numbers of fish sicken and die. This has given the hobby a bad reputation among some animal welfare groups, Portsmouth Tropical Fish such as PETA, Portsmouth Tropical Fish for treating aquarium fish as nothing more than cheap toys that are simply replaced when they die.9

 

Goldfish and bettas in particular have often been kept in cramped bowls or aquaria that are really far too small for their needs.10 In some cases fish have been installed in all sorts of inappropriate objects such as the AquaBabies Micro Aquaria, Portsmouth Tropical Fish Bubble Gear Bubble Bag and Betta in a Vase, Portsmouth Tropical Fish all of which contain live fish housed in unfiltered and entirely too small quantities of water.1112 The Betta in a Vase is sometimes marketed as a complete ecosystem if a plant is included in the neck of the vase, Portsmouth Tropical Fish some sellers claiming the fish will eat the roots of the plant. However, Portsmouth Tropical Fish bettas are carnivorous and need to be fed live food or pellet foods as they cannot survive on plant roots. Another problem is that the plant sometimes blocks the betta's passage to the water surface; they are labyrinth fishes, Portsmouth Tropical Fish and need to be able to take breaths at the surface of the water or else they will die from suffocation.

 

These types of products are not really aimed at aquarists but rather at people looking for a novelty gift, Portsmouth Tropical Fish and in fact most aquarists abhor them. Similarly, Portsmouth Tropical Fish the awarding of goldfish as prizes at funfairs is traditional in many parts of the world, Portsmouth Tropical Fish but has been criticised by aquarists and animal welfare charities alike as cruel and irresponsible, Portsmouth Tropical Fish and giving away live-animal prizes such as goldfish was made illegal in the UK in 2004.13

 

The use of live prey to feed carnivorous fish such as piranhas also brings criticism.14

 

 Fish modification

 

Modifying fish to make them more attractive as pets is an increasingly divisive issue. Historically, Portsmouth Tropical Fish artificially dyeing fish was fairly common, Portsmouth Tropical Fish with glassfish in particular often being injected with fluorescent dyes to increase their attractiveness to aquarists.15 The major British fishkeeping magazine, Portsmouth Tropical Fish Practical Fishkeeping, Portsmouth Tropical Fish has been effective in its campaign to remove these fish from the market by educating retailers and aquarists to the cruelty and health risks involved.16

 

In 2006, Portsmouth Tropical Fish Practical Fishkeeping published an article exposing the techniques for performing cosmetic surgery on aquarium fish, Portsmouth Tropical Fish without anaesthesia, Portsmouth Tropical Fish as described by Singaporean fishkeeping magazine Fish Love Magazine. The tail is cut off and dye is injected into the body to make the fish more valuable.17 The piece also included the first documented evidence to demonstrate that parrot cichlids are dyed through injections of coloured dye. Practical Fishkeeping reported that suppliers in Hong Kong were offering a service in which fish could be tattooed with company logos or messages using a dye laser; such fishes have been sold in the UK under the name of Kaleidoscope gourami and Striped parrot cichlid.18 Some people give their fish body piercings.14

 

Hybrid fish such as flowerhorn cichlids and parrot cichlids are highly controversial. Parrot cichlids in particular have a very unnatural shape that prevents them from swimming properly and makes it difficult for them to engage in their normal feeding and social behaviours. The biggest concern with hybrids is that they may be bred back with true species, Portsmouth Tropical Fish making it difficult for hobbyists to identify and breed particular species. This is especially important where hobbyists are conserving species that are rare or extinct in the wild.19 Even within a single species, Portsmouth Tropical Fish extreme mutations have been selected for by some breeders; some of the fancy goldfish varieties in particular have been criticised for having features that prevent the fish from swimming, Portsmouth Tropical Fish seeing, Portsmouth Tropical Fish or feeding properly.

 

Genetically modified fish like the glofish are likely to become increasingly available as well, Portsmouth Tropical Fish particularly in the United States and Asia. Although glofish are said to be unharmed by their genetic modifications, Portsmouth Tropical Fish they remain illegal in many places, Portsmouth Tropical Fish including the European Union, Portsmouth Tropical Fish though at least some have been smuggled into the EU from Asia, Portsmouth Tropical Fish most likely Taiwan, Portsmouth Tropical Fish via the Czech Republic.

 

 Conservation

 

There are two main sources of fish, Portsmouth Tropical Fish either from the wild or by captively breeding them. Studies by the United Nations have shown that while more than 90% of the freshwater aquarium fish traded are captive bred, Portsmouth Tropical Fish virtually all marine aquarium fish and invertebrates are caught from the wild. The few marine species bred in captivity supplement but rarely replace the trade in wild-caught specimens. 1 Fish and invertebrates that are collected from the wild can provide a valuable source of income for people in regions where other high-value exports are lacking 3. Marine fish in particular tend to be less resilient during transportation than freshwater fish, Portsmouth Tropical Fish and relatively large numbers of them die before they are finally sold to the aquarist. Although the trade in marine fish and corals for aquaria probably represents a minor threat to coral reefs when compared with habitat destruction, Portsmouth Tropical Fish fishing for food, Portsmouth Tropical Fish and climate change, Portsmouth Tropical Fish it is a booming trade and may be a serious problem in specific locations such as the Philippines and Indonesia where most of the collecting is done Catching fish in the wild can potentially reduce their population sizes, Portsmouth Tropical Fish placing them in danger of extinction in the areas where the fish are collected, Portsmouth Tropical Fish as has been observed with the dragonet Synchiropus splendidus.

 

 Fish capture

 

In theory, Portsmouth Tropical Fish wild fish should be a good example of a renewable resource that places value on maintaining the integrity and diversity of the natural habitat: more and better fish can be exported from clean, Portsmouth Tropical Fish pristine aquatic habitat than one that has been polluted or otherwise degraded. However, Portsmouth Tropical Fish this has not been the case with industries such as fur trapping, Portsmouth Tropical Fish logging, Portsmouth Tropical Fish or fishing where a similar situation existed. Historically, Portsmouth Tropical Fish wild resources have tended to be over-exploited rather than managed (see Tragedy of the Commons). Moreover, Portsmouth Tropical Fish in places where collecting for aquaria is very intensive, Portsmouth Tropical Fish there is good evidence that collecting can result in a decline in fish populations. A particular notorious example is to be found on the Philippines, Portsmouth Tropical Fish where overfishing and the widespread use of cyanide to stun the fish has caused a drastic decline in the diversity of the coral reef fish considered most desirable by aquarists 7.

 

There are several methods used to catch fish. Fish are caught by net, Portsmouth Tropical Fish trap, Portsmouth Tropical Fish or cyanide. The most damaging of these techniques is cyanide. It is a poison used to stun reef fish to make them easier to collect. However, Portsmouth Tropical Fish it can not only damage fish irreversibly, Portsmouth Tropical Fish but even kill them; even if fish or coral are not collected they may remain in contact with cyanide long enough to be killed. It has become in the interest of wholesalers and hobbyists to not purchase fish caught by this method. Because of this, Portsmouth Tropical Fish some UK-based wholesalers proudly advertise their lack of cyanide-caught animals. Now, Portsmouth Tropical Fish the Philippines have started a movement away from cyanide and towards nets.

 

The practice of collection in the wild for eventual display in aquaria has several disadvantages. Collecting expeditions can be lengthy and costly, Portsmouth Tropical Fish and are not always successful. The shipping process is very hazardous for the fish involved; mortality rates are high. Many others are weakened by stress and become diseased upon arrival. Fish can also be injured during the collection process itself, Portsmouth Tropical Fish most notably during the process of using cyanide. This poisoning substance if often used for collecting freshwater species as well, Portsmouth Tropical Fish specially in muddy water bodies with lots of vegetation in it, Portsmouth Tropical Fish which would make catching small and fast moving fish very difficult.

 

More recently, Portsmouth Tropical Fish the potentially detrimental environmental impact of fish and plant collecting has come to the attention of aquarists worldwide. These include the poisoning of coral reefs and non-target species, Portsmouth Tropical Fish the depletion of rare species from their natural habitat, Portsmouth Tropical Fish and the degradation of ecosystems from large scale removal of key species. Additionally, Portsmouth Tropical Fish the destructive fishing techniques used have become a growing concern to environmentalists and hobbyists alike. Therefore, Portsmouth Tropical Fish there has been a concerted movement by many concerned aquarists to reduce the trade's dependence on wild-collected specimens through captive breeding programs and certification programs for wild-caught fish. Among American keepers of marine aquaria surveyed in 1997, Portsmouth Tropical Fish two thirds said that they prefer to purchase farm raised coral instead of wild-collected coral, Portsmouth Tropical Fish and over 80% think that only sustainably caught or captive bred fish should be allowed for trade.

 

 Captive breeding and aquaculture

 

Since the Siamese Fighting Fish (Betta splendens) was first successfully bred citation needed in France in 1893, Portsmouth Tropical Fish captive spawning techniques have been slowly discovered. Captive breeding for the aquarium trade is now concentrated in southern Florida, Portsmouth Tropical Fish Singapore, Portsmouth Tropical Fish Hong Kong, Portsmouth Tropical Fish and Bangkok, Portsmouth Tropical Fish with smaller industries in Hawaii and Sri Lanka.citation needed Captive breeding programs of marine organisms for the aquarium trade have been urgently in development since the mid-1990s. Breeding programs for freshwater species are comparatively more advanced than for saltwater species. Currently, Portsmouth Tropical Fish only a handful of captive-bred marine species are in the trade, Portsmouth Tropical Fish including clownfish, Portsmouth Tropical Fish damselfish, Portsmouth Tropical Fish and dwarf angelfish.22

 

Breeding programs by aquarists have helped to preserve species that have become rare or extinct in the wild, Portsmouth Tropical Fish most notably among the Lake Victoria cichlids. Some species of aquarium fish have also become important as laboratory animals, Portsmouth Tropical Fish with cichlids and poecilids being especially important for studies on learning, Portsmouth Tropical Fish mating, Portsmouth Tropical Fish and social behaviour. Aquarists also observe a large number of fishes not otherwise studied, Portsmouth Tropical Fish and thereby provide valuable data on the ecology and behaviour of many species.

 

Captive fish breeding has reduced the final price of many species in the fish trade, Portsmouth Tropical Fish allowing a large amount of formerly budget restricted fish be kept by home aquarists. Also, Portsmouth Tropical Fish selective breeding has led to several variations among a single species, Portsmouth Tropical Fish creating a wider stock of fish in the trade. At this point, Portsmouth Tropical Fish however, Portsmouth Tropical Fish captive bred marine fish tend to be more expensive than their wild counterparts.22

 

Aquaculture is the cultivation of aquatic organisms in a controlled environment. Supporters of aquaculture programs for supply to the aquarium trade claim that well-planned programs can bring benefits to the environment as well as the society around it. Aquaculture can help in lessening the impacts on wild stocks, Portsmouth Tropical Fish either by using raised cultivated organisms directly for sale or by releasing them to replenish wild stock, Portsmouth Tropical Fish although such a practice is associated with several environmental risks.

 

 Invasive species

 

Serious problems can occur when fish originally kept in ponds or aquaria are released into the wild. While tropical species of fish will not live for long in temperate zone climates, Portsmouth Tropical Fish fish released into places with similar climatic conditions to those that they originally came from can survive and potentially form viable populations. Species that have established themselves in places that they are not native to are called exotic species. Examples of exotic fishes that have become established outside their normal range are the various species of cichlids in Florida, Portsmouth Tropical Fish goldfish in temperate waters, Portsmouth Tropical Fish and South American suckermouth catfishes in warm waters around the world.2324 Some of these exotic species can become extremely disruptive preying on, Portsmouth Tropical Fish or competing with, Portsmouth Tropical Fish the native fish (see invasive species). Many marine fish have also been introduced into non-native waters.

 

A pond is typically a man made body of water smaller than a lake. However the difference between a pond and an artificial lake is subjective. They are both formed by ponding water. Ponds can be made by excavating a hollow in which water may lie, Portsmouth Tropical Fish filling an existing depression with groundwater or water diverted from a stream, Portsmouth Tropical Fish or by forming a dam to impound the water in a valley.

 

The techniques may be combined to form a reservoir in flat country by enclosing an area with an embankment. Such a pond, Portsmouth Tropical Fish unless very small, Portsmouth Tropical Fish is usually called a reservoir. In some cultures, Portsmouth Tropical Fish the meaning has been extended to include small bodies of water impounded naturally. (Oxford English Dictionary)

 

Scientifically, Portsmouth Tropical Fish a pond is any man made body of water where light is found in the entire pond body of water. A lake is any body of water that has a profundal zone; there is as limit of effective light penetration for organisms.

Contents

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    * 1 Nomenclature

    * 2 Characteristics

    * 3 Examples

    * 4 See also

    * 5 Gallery

 

 Nomenclature

 

In origin, Portsmouth Tropical Fish pond is a variant form of the word pound, Portsmouth Tropical Fish meaning a confining enclosure. As straying cattle are enclosed in a pound so water is enclosed in a pond. In earlier times, Portsmouth Tropical Fish ponds were man-made and utilitarian; as stew ponds, Portsmouth Tropical Fish mill ponds and so on. The significance of this feature seems in some cases, Portsmouth Tropical Fish to have been lost when the word was carried abroad with emigrants so that in places like the United States, Portsmouth Tropical Fish natural pools are often called ponds.

An Australian rock pond. Heathcote National Park

An Australian rock pond. Heathcote National Park

 

A pond is sometimes characterized as being a small body of water that is shallow enough for sunlight to reach the bottom, Portsmouth Tropical Fish permitting the growth of rooted plants at its deepest point.

 

Pond usually describes small bodies of water, Portsmouth Tropical Fish generally smaller than one would require a boat to cross. Another definition is that a pond is a body of water where even its deepest areas are reached by sunlight or where a human can walk across the entire body of water without being submerged. In some dialects of English, Portsmouth Tropical Fish pond normally refers to small artificially created bodies of water.

 

Though not generally accepted, Portsmouth Tropical Fish some regions of the United States define a pond as a body of water with a surface area of less than 10 acres (40,000 m²).

 

Regional differences include the use of the word pond in New England, Portsmouth Tropical Fish and Maine in particular, Portsmouth Tropical Fish for relatively large waterbodies. For example, Portsmouth Tropical Fish Great Pond, Portsmouth Tropical Fish Maine, Portsmouth Tropical Fish is over 10 square miles (26 km²) in area.

 

In areas which were covered by glaciers in the past, Portsmouth Tropical Fish some ponds were created when the glaciers retreated. These ponds are knowns as kettle ponds . Walden Pond in Concord, Portsmouth Tropical Fish Massachusetts is a well known example. Kettle ponds are usually quite deep and clean because they are fed by underground aquifers rather than surface streams.

 

The term is also used for temporary accumulation of water from surface runoff (ponded water).

 

There are various regional names for naturally occurring ponds. In Scotland, Portsmouth Tropical Fish one of the terms is lochan, Portsmouth Tropical Fish which may also apply to a large body of water such as a lake.

 

The word "pond" is sometimes also used to refer to the Atlantic Ocean in the expression "across the pond" (a deliberate idiomatic understatement).

 

 Characteristics

 

Typically, Portsmouth Tropical Fish a pond has no surface outflow draining off water and ponds are often spring-fed. Hence, Portsmouth Tropical Fish because of the closed environment of ponds, Portsmouth Tropical Fish such small bodies of water normally develop self contained eco-systems. Ponds in heavily vegetated areas also display the formation of "scum", Portsmouth Tropical Fish which is a common term for dead and decaying vegetation condensing on top of the water. A contributor to this is the presence of algae, Portsmouth Tropical Fish which multiply quickly in a nutrient-rich eutrophic pond exposed to strong daylight. Decaying flora provide significant amounts of such nutrients.

 

In Indian subcontinent, Portsmouth Tropical Fish Hindu temples usually have a pond nearby so that pilgrimages can take bath. These ponds are considered sacred. In medieval times in Europe, Portsmouth Tropical Fish it was typical for many monasteries and castles (small, Portsmouth Tropical Fish partly self-sufficient communities) to have fish ponds. These are still common in Europe and in East Asia (notably Japan), Portsmouth Tropical Fish where koi may be kept.

 

 Examples

 

Thousands of examples worldwide are available to illustrate the pond; a few of these are:

 

    * Antonelli Pond, Portsmouth Tropical Fish California, Portsmouth Tropical Fish USA

    * Big Pond, Portsmouth Tropical Fish Nova Scotia

    * Christian Pond, Portsmouth Tropical Fish Wyoming, Portsmouth Tropical Fish USA

    * Hampstead Ponds, Portsmouth Tropical Fish England

    * Oguni-numa Pond, Portsmouth Tropical Fish Japan

    * Pete's Pond, Portsmouth Tropical Fish Botswana

    * Ro˛mberk Pond, Portsmouth Tropical Fish Czech Republic

 

 See also

 

    * Chemical pond

    * Duck pond

    * Cooling pond

    * Solar pond

    * Fountain

    * Pond Aeration

    * Pond Ecology

    * Tarn

    * Treatment pond

    * Tide pool

    * Water garden

    * Aquascape, Portsmouth Tropical Fish Inc.

 

 Gallery

 

A picture of the pond located at "University Hills Park", Portsmouth Tropical Fish College Park, Portsmouth Tropical Fish Maryland USA

 

 

           

 

A pond in Peterhof formal garden. In a baroque garden such as this, Portsmouth Tropical Fish it would normally have been called a basin, Portsmouth Tropical Fish following French practice.

 

 

           

 

Garden pond.

 

 

           

 

Close-up of pond in the forests of Samothraki island. The colors of the rocks are due to deposition of minerals.

 

 

Garden pond.

 

 

           

 

a typical Kerala pond. Every major Hindu temples will have a sacred pond near to it. It is used by the pilgrimages to take holy bath.