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OPEN COURSE AQ5 D01 ORNAMENTAL CULTURE

GENERAL INTRODUCTION

An is a marvelous piece of nature in an enclosed space, gathering the attraction of every human being. It is an amazing window to the fascinating underwater world. The term ‘aquarium’is a derivative of two words in Latin, i.e aqua denoting ‘water’ and arium or orium indicating ‘compartment’. , an English naturalist, was the first person to actually use the word "aquarium", in 1854 in his book The Aquarium: An Unveiling of the Wonders of the Deep Sea. In this book, Gosse primarily discussed saltwater aquaria.

Aquarium or ornamental fish keeping has grown from the status of a mere hobby to a global industry capable of generating international exchequer at considerable levels. History shows that Romans have kept aquaria (plural for ‘aquarium’) since 2500 B.C and Chinese in 1278-960 B.C. But they used aquaria primarily for rearing and fattening of food . Chinese developed the art of selective breeding in and , probably the best known for an aquarium. Ancient Egyptians were probably the first to keep the fish for ornamental purpose. World’s first public aquarium was established in Regents Park in London in 1853.

Earlier only coldwater fishes were kept as pets as there was no practical system of heating which is required for tropical freshwater fish. The invention of electricity opened a vast scope of development in aquarium keeping. The ease of quick transportation and facilities for carting in temperature controlled packaging has broadened the horizon for this hobby. Today, a person in cold water region can enjoy the beauty of tropical as well as the exotic marine . The modern facilities for ornamental fish breeding and culture and the easy availability of wide variety of aquarium equipments and fish feeds have greatly increased the number of aquarium hobbyists all over the world.

Choosing a spot for an aquarium First, you will need to think about how much free space you have for your aquarium, whether that free space is open to , and which shape that is best suited for that free space. Never place an aquarium in direct sunlight and keep the aquarium away from heating or cooling surfaces. Sunlight and heating or cooling surfaces will cause sudden and drastic changes in the temperature within the aquarium, and sunlight will also promote the growth of in the water.

Keep your aquarium away from machines that give out a lot of sound or cause vibration, like the washing machine, since this will stress the fish. Water accessibility and easy disposal of dirty water and waste are some other important factors to consider while selecting a good spot for your aquarium as you don’t want to run around with buckets of water in your entire house. One needs to clean and change water at least monthly and better once a week. So, choose a place where one can work easily and without any interference. In a family with children, special care has to be taken to keep the aquarium away from areas of frequent activity.

- 1 - You should also consider that an aquarium is very heavy so the chosen spot has to be able to support the weight of the aquarium. Any aquarium over 10 gallons/ 40 L will weigh at least a hundred and fifty pounds / 70 Kg when filled and decorated. The weight comes chiefly from the glass and the water, and decoration such as gravel will further add to this weight. Heavy aquaria will need to be kept on a sturdy stand rather than a shelf or a desk.

Choosing an aquarium come in many shapes and sizes. For a beginner, the convenient size will be 60cm X 30cm X 30cm because too small an aquarium may not worth watching. It is advisable to choose an aquarium that is at least 10 gallons/ 40 L, (1 gallon is approximately equal to 4.5 litres) since small aquariums are much more difficult to maintain. The waste build up in small aquariums is quick and quite large in comparison with a larger aquarium. A small aquarium will therefore require very frequent water changes. Changes in temperature or water chemistry will also take place more quickly in small aquariums. Rapid changes in the temperature or water chemistry are harmful for fish.

Fish aquariums come in many shapes ranging from rectangular to hexagonal or even cylindrical or spherical. While making your purchase, it is not only the beauty of the piece that counts. Ordinary matters like how easy it will be to clean out the aquarium regularly, and how to keep all the nooks and crannies hygienic are important considerations. The height of the aquarium is also a very important aspect. An aquarium that is very deep is complicated to keep for the beginner . Increased height means greater difficulty when cleaning and your aquarium might therefore always carry some amounts of waste even after a thorough clean up. Poor light penetration is another problem with a deep aquarium. Plants will not thrive in water that has poor light penetration and special is therefore needed in deep planted aquariums. Moreover, human eyes are designed to view rectangular things rather than materials of varied shape. It is always better to use larger or at least moderately sized tanks since it is easier to keep a larger tank in good condition. And rectangular tanks have more surface area exposed to air, increasing the scope for more oxygen dissolving in water; a factor which can increase the number of fishes that could be accommodated in the tank.

Principal considerations for selecting fishes for aquarium are colour range, compatibility for co existence, cost, adaptability to environmental conditions, feed preferences and disease resistance.

Common Tank Sizes and their Capacities:

Maximum Tank Length Width Depth Surface Volume fish weight (cm) (cm) (cm) are (cm2) (cm) capacity (kg) (no.) 30 15 15 450 8 8 15 45 25 25 1,125 35 35 38 60 30 30 1,800 67 67 60 90 30 30 2,700 101 101 90 120 30 30 3,600 135 135 120

- 2 - IMPORTANT FRESHWATER ORNAMENTAL FISHES

1. Gold fish:- More than 20 varieties of goldfish are available, with variegated colours and shapes. Given proper care their life span is up to 25 years.

2. : Their longevity is 3-4 years. Excessive feeding decreases their lifespan. Males show a spectrum of colours. It gives birth to young ones (live-bearing). can survive in poorly oxygenated water.

3. Kissing :- It has accessory respiratory organs and therefore can live in low oxygen levels. Due to its pleasing colour and behavioral peculiarities, this is a widely welcomed ornamental.

4. :- Though beautiful, it has a tendency to attack other fishes and therefore usually not suggested for keeping with other fishes in a tank.

5. Platy:- It has maximum colour range among freshwater ornamental fishes. They are live beares.

6. Sword tail:- They are noted for their beauty and peculiarities of breeding. They also give birth to young ones.

7. Zebra fish:- It has spectacularly coloured lines on the body and hence the name. They are carnivores.

8. Angel:- Although silent in posture and movement, the fish frequently attacks small sized fishes. Many varieties are available.

9. Mollies:- More than ten varieties are present and are live bearers.

10. Fighter:- Males are more colourful than females. Two males are never kept in a tank along with females because they fight each other for mating with female.

11. Orange chromide (‘pallathi’):-A near relative of pearl spot (‘karimeen’); the fish has numerous orange spots on the body. They can be bred and reared in aquaria.

12. Sucker:- Brilliant colours are not available in suckers. But they are considered in aquarium due to their cute shape and behaviour. They clean the aquarium by feeding on algae.

WORLD AQUARIUM FISH TRADE AND PRESENT STATUS

During the last four decades, there has been considerable growth and diversification in the international trade in ornamental fishes which is valued at about US $ 5 billion. The major players in this market include USA, Europe, Japan, Australia, Singapore, Indonesia, Philippines and Sri Lanka. In recent years much interest has been shown by the home hobbyists and public aquaria to keep marine ornamentals. The proportion of marine fish in the total global trade has increased from less than 15% to about 40%. The market for ornamental fishes consists of 99% home-hobbyists and 1%

- 3 - public aquaria and research institutes. The market is mostly located in areas with high density population, industrial areas and cool climate. The industrial chain which determines the price is explained as: Fisherman/Breeder Exporter Airline Importer/Wholesaler Retailer

Hobbyist

The importer/wholesaler plays a very important role as the link between producer and consumer. Only perfect, good and healthy fish have good market value. The extra cost of quality control in a fish house (at both export and import level) with good management and trained staff thus adds to the value of the fish. According to statistics, 50% of the suppliers are located in Asian countries. Singapore. Thailand, Hong Kong, Japan and Malaysia are the major suppliers of freshwater fish, while Indonesia, Philippines and Sri Lanka are the major suppliers of wild-caught marine fish. Philippines is known for the direct export of marine exotic varieties. Singapore exports relatively few salt water fish. Originating from its own resources but depends mainly on re-export of Indonesia-caught fish and , while Sri Lanka exports her reef fishes and fishes coming from Maldives. Those fishes originating from the Maldives are either usually available in lesser numbers in Sri Lankan waters or are only seasonal. The largest import markets for are USA, European countries and Japan. Approximately 14 percent of British homes and 8 percent of USA homes keep ornamental fish. 150 million ornamental fish are sold on a worldwide basis each year. Current opinions suggest that about 90% of the freshwater ornamentals traded are captive-bred, while 99% of the marine ornamentals exported are caught from the wild.

Indian Scenario: India, despite its vast expanse of sea coast and flow of perennial rivers and consequent abundant resources of freshwater and marine ornamentals is still way behind other developing countries in the matter of development of this trade. In fact, the natural resources of India are more varied as compared to those of Sri Lanka, , Singapore, Indonesia and Malaysia. Several freshwater varieties of Indian fishes are well known in the international market. The lagoons and coral reefs of Lakshadweep islands, Andaman & Nicobar Islands, Okha-Pintan-Gulf of Kutch complex, coast of Kerala around Kanyakumari, Gulf of Mannar and Palk Bay abound with highly attractive and varied of ornamental fishes. We could certainly make a good deal of money and enjoy a considerable share in the world trade by supplying marine ornamental fishes and live rocks originating from the vast resources which are the basic materials essential in keeping the aquarium environment healthy. Live rocks afford organisms living in it a much longer life span. Poor knowledge on the part of our people about aquariculture and live fish trade could be the principal reason for our backwardness in this field. USA is the single largest market for ornamental fish from India.

India's contribution to global aquarium trade is worth a mere 10 crore rupees while we have a great potential to increase the level of exports to about US$ 30 million every year. There are at least 150 varieties for commercial exploitation,' including clown fishes, damsels, marine angels, , surgeon fishes, tangs, butterfly fishes, etc. Calcutta, Mumbai and Chennai are major breeding centres for freshwater ornamentals. There are about 150 full time and 1500 part time ornamental fish breeders in the country.

- 4 - FILTRATION AND FILTERS

Choosing the correct filtration system for an aquarium is an important decision that will impact not only the type and quantity of livestock that you wish to keep, but also the amount of maintenance that the system will require. The filtration system is responsible for keeping the water clear and free of particulate matter (tiny fragments of plant material, leftover food, feces, waste products from the fish, etc.) and toxic compounds that are dangerous to the inhabitants.

The three categories of filtration

There are three types of filtration that are necessary for the health of any aquarium:

 Mechanical  Chemical  Biological

Before choosing a filtration system, it is important to understand all three, and how they will benefit your aquarium.

Mechanical

Mechanical filtration is the process in which particulate matter is removed from the water. To accomplish this, the aquarium water is forced through a medium (material) that is designed to catch and hold these tiny particles. This media is available in many forms including different types of foam, filter floss, pads, micron paper pleats, and diatomaceous earth. To function properly, it is important that this media is cleaned regularly to remove the particulate matter it has trapped, prior to the material decaying and adding to the waste products in the aquarium.

All mechanical filters over time will become clogged with particulate matter. When this occurs, it will cause the water flow to either decrease, or flow around the material instead of through it. At that point, the hobbyist should recognize the need to clean the filter. By oversizing the mechanical filter, it may be months before the filter loses its efficiency, which means that it will be months between cleanings. Even though the aquarium may look clean and free of particulate matter, the filter will be holding large amounts of (tiny pieces of decomposing plant or animal material) and other debris that is slowly decaying and contaminating the water with toxic breakdown products such as , nitrites, and ultimately nitrates. These waste products, therefore, actually reduce the number of aquarium inhabitants that can be housed safely.

Chemical

Chemical filtration removes toxic or unwanted chemicals as the water passes through a chemical media or ion exchange resin. There have been a number of advancements in the past years, giving us new products that are targeted at removing specific chemicals or excess nutrients from the water. If used correctly, these media can be incorporated into the filtration to both improve water quality, and reduce the amount of maintenance and water changes needed to sustain a healthy aquarium. Chemical media work by any one of the following mechanisms: (a) adsorbing chemical wastes in gaseous

- 5 - form like hydrogen sulphide (b) neutralizing the toxic chemical by forming inert compounds (c) binding the harmful waste chemical to form complexes so that the former is not available in water to cause toxicity. E.g activated carbon, zeolite, clinoptiolite.

Biological

In biological filtration, different types of convert the toxic chemical byproducts produced by the aquarium inhabitants into less toxic nutrients. This breakdown process by the bacteria is called the Cycle or ‘cycling’.

In the , the waste products of the fish, plants, and invertebrates, along with any dead organisms or uneaten food, are broken down by bacteria and fungi into ammonia. Ammonia is extremely toxic to all of the aquarium inhabitants, and is broken down into nitrites by oxygen-loving bacteria known as Nitrosomonas. Although nitrites are not as toxic as ammonia, even at low concentrations in the aquarium, they can still be harmful to fish and invertebrates. Again, another bacteria called Nitrobacter, which also utilizes oxygen, acts in a similar way as Nitrosomonas, and essentially changes nitrites into relatively harmless nitrates. Nitrates, at low to moderate levels, will not harm most fish or invertebrates, but can be the source of some unsightly algae problems if not controlled by both the chemical filtration and water changes.

For the Nitrogen Cycle to work properly, there must be an area for a sufficient number of these bacteria to grow, and their need for oxygen must be met. Biological filtration occurs to some degree in all filters and in areas of the aquarium where these bacteria are present such as the water, , and decorations. The capacity of a biological filter is determined by the available surface area for bacterial growth and the oxygen content of the water passing over them. Not all filters have the same capacity when it comes to biological filtration. Filters in which the biological media is exposed to the air are going to have the greatest capacity.

- 6 - Types of filters

There are many types of filters currently on the market that range in size, price, and their ability to perform the three essential types of filtration. These filters include:

 Internal  Under Gravel  Power  Canister  Wet/dry

It is important to know what type of livestock you plan to keep before choosing a filter for your system. Some aquariums, such as a live planted freshwater aquarium, do not require a filter that is efficient biologically, but do require a filter that is efficient in both chemical and mechanical filtration. On the other hand, an unplanted, heavily- stocked African aquarium is going to require a filter, or combination of filters, that is efficient in all three types of filtration.

Internal Filters

Internal filters come in many different styles, and are simply placed in the aquarium either on the substrate, or mounted to one of the sides with suction cups. They include corner box filters and models. For most internal filters, an airline needs to be attached to the inlet of the filter, and is driven by an air pump located outside the aquarium. Air is pumped into the bottom of the filter, moves through the filter, and is then released through the top of the filter where it dissipates to the surface of the water. The action of the air bubbles creates water movement through the filter which enables it to perform the filtration.

Corner Box Filters: The corner box filter is typically shaped to fit into the corner of the aquarium. It is simply a box with slots in the top and bottom which allow water to flow through it. Placed on the gravel, the air is pumped into the bottom of the filter from a remote air pump. The air draws the water through the filter from the bottom and leaves the filter at the top.

The corner box filter is designed to perform all three types of filtration, but the efficiency of all types are limited due to the low oxygen content and the low level of water flow. Layers of floss for mechanical filtration and activated carbon for chemical filtration are the typical media used in this type of filter, although it can be customized with any type of mechanical or chemical materials. Bacteria growing on the filter media provide the biological filtration.

This filter should be cleaned/changed regularly depending on the aquarium load, and care should be taken not to destroy the beneficial bacteria located in the mechanical filtration media. This can be accomplished by rinsing the media in the aquarium water that is removed during a routine water change, rather than in tap water. Only replacing half of that media at a time will preserve the bacteria needed for the biological filtration.

- 7 - Sponge Models: The sponge filter features a design in which a u-shaped tube is used to pull water through a sponge-like material that features a very large surface area. A separate air pump is needed to provide the air flow.

The sponge material is capable of both mechanical and biological filtration. That is mechanical filtration occurs as the sponge traps particulate matter suspended in the water that is passing through it. Biological filtration is provided by the beneficial bacteria living on the sponge. Its mechanical and biological effectiveness is limited, due to the low amount of oxygen and volume of water drawn through the filter.

This type of filtration is very inexpensive and is easy to maintain. To remove the organic matter before it begins to deteriorate, every week the sponge filter should be rinsed in water removed from the aquarium. Using aquarium water is important when cleaning these filters so you do not risk killing the beneficial bacteria that are responsible for the biological filtration.

Both types of internal filters have limited use, only being effective in small aquariums with a small number of inhabitants. Typical uses for these filters are in breeding and hospital tanks. Because there are no moving parts in the aquarium when using this style of filter, small newly hatched or reared fry cannot be drawn into the filter, which results in lower mortality rates. For the hospital tank, the sponge or floss material can be set into the main aquarium for a few days to become colonized with beneficial bacteria prior to being put to use in the hospital tank. At that time, the sick fish can be acclimated into the hospital tank for treatment without having to cycle the aquarium, avoiding additional stress on the ill fish. Again, these filters are very inexpensive and are easy to maintain, but have limited applications.

Under Gravel Filters

An under gravel filter employs a slotted plate that is installed underneath the substrate (e.g.; gravel) and has multiple tubes, called uplift tubes, that extend upward toward the surface of the water. Either an air stone is installed inside the uplift tubes, or a power head is placed on top of the tube, to draw water through the substrate and up through the tubes.

The mechanical filtration is achieved as the water flows through the substrate, which traps any particulate matter. It is very important that a gravel cleaner is used on this type of set-up weekly to remove the particulate matter before it starts to decay and becomes a part of the biological load.

The biological filtration is accomplished by the bacteria living on the large surface area of the substrate that the water is passing through. The biological filtration, however, is limited due to the low oxygen content of the water passing through the substrate. Another downfall to the biological filtration with this type of filter is that the water does not flow evenly through the substrate due to different substrate depths and decorations placed on the substrate. This creates dead spots within the filter bed. Detritus builds up in these dead spots and can cause pockets of dangerous levels of hydrogen sulfide. Again, it is important to regularly agitate and clean the substrate when using this type of filtration. Some models of under gravel filters have carbon cartridges to provide chemical filtration.

- 8 - Aquaria utilizing under gravel filters tend to run higher nitrate and phosphate levels due to the inefficiency of both the mechanical and biological filtration. Again, weekly gravel cleanings along with water changes are needed to maintain a healthy system when using these filters. These filters are typically in the low to medium price range depending on whether air stones or power heads are employed. They can be used on various aquarium set-ups, but the amount of livestock that can be maintained will be limited. The under gravel filters are not recommended for freshwater planted aquaria due to the water flow through the gravel, which is unnatural to the plants and affects their abilities to absorb nutrients.

Power Filters

"Power filters" is the term used to describe the vast array of filters available on the market that are designed to hang on the back of the aquarium. Most of these filters employ all three types of filtration and are very easy to maintain. These units also include the pump necessary to draw the water into the filter and are completely self-contained. The aquarium water is pulled into the filter using a u-tube and flows through a cartridge or other type of filter media. Most models require filter cartridges, usually containing activated carbon, which are designed for the specific model of filter.

The mechanical filtration of the power filter is accomplished as the aquarium water passes through a floss or foam material, and is moderately efficient. A weakness in the mechanical filtration of most power filters is that the cartridges tend to clog relatively quickly causing the water to pass over the cartridge instead of passing through it. It is important to remove the media regularly and rinse the debris from the material. The frequency of cleaning and replacing the cartridges is going to depend on the biological load of the system.

The chemical filtration is typically integrated into the filter cartridge that usually contains activated carbon. Some models include chambers in which more specialized chemical medias and resins can be added. The efficiency of the chemical filtration is similar to the efficiency of the mechanical filtration and is going to depend on the percent of the water passing through the cartridge. Again, the bio load of the system is going to dictate how often the cartridge and media need to be replaced.

Biological filtration also occurs within the filter cartridge. The mechanical and chemical sections of the filter harbor large numbers of beneficial bacteria that aid in the nitrogen cycle. The efficiency of the biological filtration within the cartridge is limited due to the moderate amount of oxygen present in the water passing through the media. The downside to these cartridges is that when they need to be replaced, you lose the entire bacterial bed when changing the seasoned cartridge with a new one. Before replacing the old cartridge, it is a good idea to place the new cartridge in a spot either in the aquarium or the filter to allow the beneficial bacteria to grow prior to removing the old one.

Many power filters also come with biowheels. Biowheel is a part of power filter that incorporate a wheel with pleats for surface area, that spins as the water passes over it. A biowheel is an excellent biological filter due to the amount of air contact the water receives as the wheel spins. These wheels require very little maintenance, and they

- 9 - should only be rinsed periodically in water taken from the aquarium to remove any buildup.

Power filters are not suited for either freshwater planted or saltwater aquariums. Ideally, the water surface of a freshwater planted aquarium should remain undisturbed so the concentrations of in the water can be maintained.

Canister Filters

Canister filters are pressurized units that are typically placed beneath the aquarium and perform all three types of filtration. They are available either in a complete unit which includes its own pump, or in a modular form that requires an additional pump. The modular units are useful when plumbed in-line with other types of filtration, such as a wet/dry filter. The complete units use a u-tube as the water intake and typically a spray bar for the water return. Once the system is installed on the aquarium, a siphon is started allowing the water to flow from the aquarium down to the canister filter. The water entering the filter will first pass through a mechanical media such as floss or pads and will then be forced through the chemical media. After the chemical filtration is complete, the water then enters the last chamber containing the biological mediium where the nitrogen cycle is completed prior to the water returning to the aquarium.

The mechanical filtration of canister filters is far superior to any other type of filter. This is due to the fact that the canister filter is pressurized and the water can be forced through a finer material that can trap smaller particulate matter. These materials, or cartridges in some cases, have a rating that indicates the size of particles that the filter will trap. This rating is measured in microns. The lower the micron value, the smaller the particle of matter that can be removed by the filter.

The chemical filtration of canister filters is going to be the most efficient compared to other filters available. Again, this is because the water is pressurized and is forced through the media. Another advantage of the canister filters is the flexibility of the types of chemical filtration media that can be added. Activated carbon is the suggested mediium to use in general maintenance, but there are more specialized media and resins that can be incorporated when needed.

The biological filtration of canister filters is limited due to the amount of oxygen present in the water passing through the filter. Because they are pressurized filters, there is no water to air contact within the biological media. This means that this area of filtration will not be as efficient as other types of filters available.

Wet/Dry Filters

Wet/dry filters are typically located beneath the aquarium and use an overflow device to regulate the amount of water supplied to the filter. The overflow device works automatically with an oxidation reduction potential (ORP) sensor. The overflow device incorporates two boxes, one inside, and one outside the aquarium, usually in the back. A U-tube is used to move the water, via a siphon, from the box inside the aquarium to the one on the back of the aquarium. The overflow box that is located inside the aquarium can be raised or lowered, which will alter the water level in the aquarium. After flowing into the box on the back of the aquarium, the water flows through a pre-filter material

- 10 - (usually a sponge), which traps any large particulate matter prior to entering the main filter housed below the aquarium. As the water drops to the filter, it is agitated causing the water to mix with air. The aquarium water is then dispersed over the biological media chamber via a drip plate or spray bar. The water level in the main part of the filter is maintained at 1/3 to 1/2 full, allowing a large part of the biological media to be exposed to air. After the water passes through the biological media, it flows through the bottom of that chamber into the other part of the filter, which is often referred to as the . In this open area of the filter, a , chemical medias, denitrator, or reactor can be incorporated. The water pump responsible for returning the water into the aquarium is also located in the sump. The water pump is installed using either a bulkhead for in-line operation, or a submersible pump can be located directly in the sump.

The mechanical filtration of the wet/dry filter is accomplished by both the pre- filter material, and the sponge that is located between the biological filter and the sump section. Because of the design of wet/dry filters, the water flow can not be restricted, so the are large-pored allowing water to pass through easily. This means that the mechanical filtration is limited to removing only the larger particulate matter, and is not very efficient.

The chemical filtration is accomplished by placing a chemical media in the filter, typically in either a tray below the biological media, or against the sponge that separates the sump and biological section of the filter. Because the water merely flows through, and is not forced through the media, the chemical filtration of these filters is not very efficient.

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Ozonisers, Protein Skimmers, Aquarium Vacuum Cleaners and Aeration devices

PROTEIN SKIMMER: A Protein Skimmer or foam fractionator is a device used in marine aquaria to remove organic compounds such as food and waste particles from water. This technique exploits the affinity of organic waste to adsorb to air bubbles. In basic terms, organic-waste-laden aquarium water is reacted in a column of air bubbles, the waste sticks in the foam, and the foam collected.

Dissolved Organic Compounds (DOCs) are the waste molecules skimmers are designed to remove; these are produced as byproducts from the breakdown of biological materials. As an air bubble moves through the column of organic-laden water, the electrically charged protein molecules (which contain electrically polar and electrically non-polar regions) are attracted to the air/water interface of the bubble. The polar regions of the molecule (made up of nitrogen, oxygen, etc.) are attracted to the air/water interface and these polar "tails" stick out away from the air bubble into the water column. The non- polar regions stick out into the air bubble because it does not "like" to be in contact with the polar solvent (i.e. water). As the protein-laden bubble reaches the top of the protein skimmer, the proteins begin to accumulate which creates a stable foam bubble. These

- 11 - stable foam bubbles take a long time to burst. Thus, the proteins slowly are concentrated at the top of the skimmer where they are slowly pushed through the "throat" of the protein skimmer and into the collection cup. The longer that the DOCs are in contact with the bubbles, the more of them will attach to the bubbles, the more of them will be removed. Longer contact times allow for less adherent molecules to be attracted and "stuck" to an air bubble. Other compounds besides DOCs can be removed as well. These may be VOCs (volatile organic compounds), POC (particulate organic compounds), uneaten fish food, trace elements, secondary metabolites from soft , bacteria, macro- and micro-, coral eggs and and other similar compounds.

A skimmer has three essential parts:

1. The skimmer body, where most of the contact between the DOCs and water takes place. 2. The foam separation area, or riser tube, where the organic laden foam is separated from the water. 3. A collection cup, where the foam spills over the riser tube and is drained away.(image below).

- 12 - OZONISER: Ozonisers are electrical equipments used to purify aquarium water by diffusing ozone into it. Ozonizers can be utilized in setups as well as freshwater systems with a pH above 7.5.

Certain organic wastes are unable to be removed by conventional mechanical or biological filtration. Ozone oxidizes the water, breaking down these waste products. This makes the wastes easier to be processed by the filtration, resulting in clear water. Ozone also provides additional oxygen to the aquarium as well as killing bacteria and parasites by eating away at their cell membranes.

Ozonisers work by creating electrical discharges that combine oxygen molecules to form ozone molecules. The generated ozone is then added to an ozone reactor or protein skimmer in regulated amounts to diffuse into the aquarium water. Caution needs to be taken in adjusting the amount of ozone added to the water, as too much ozone can be hazardous to the fish as well as anyone nearby.

ORP, or Oxidation Reduction Potential, is a measurement used to determine the oxidizing potential in water. In aquarium water, chemical reactions create a transfer of electrons that can be measured by a sensitive voltmeter to determine the ORP level. As ozone is introduced to the water, the ORP level gradually increases as the water gets sterilized. This ORP reading is used to further control the regulation of an ozonizer unit with a Redox controller, similar to how a thermostat controls the operation of a heater. When operating an ozone system, the ORP level should be 300-350 mV, which indicates an oxygen-rich environment with low waste levels. An ORP level higher than 350mV should be avoided, as it will create levels of ozone sterilization that could be hazardous to the aquarium inhabitants.

Deciding on the amount of ozone to add to your aquarium will depend on the volume of water, water and air flow, existing equipment, and the biological load in your

- 13 - system. In most cases, ozone production should be 5-15 mg/hour for every 25 gallons of water. Systems with fewer fish can be maintained with less than 5mg/hour per 25 gallons, while heavier bio loads with few invertebrates should be towards the 15mg/hour per 25 gallons. It is possible to dose in greater quantities of ozone for very heavy fish-only populations, however extreme caution will need to be taken. Due to the potential dangers of this, dosing above 15mg/hour per 25 gallons is normally not suggested.

The first step in adding ozone involves an air pump to force air into the ozonizer. An air drier is also used to reduce humidity and ensure ozone is generated in an efficient manner. After the ozone is produced, it should never be directly diffused into the water. To help diffuse it in a safe, regulated manner, the ozone is run through a pressurized unit such as a protein skimmer or ozone reactor. Not only does this properly diffuse the ozone into the water, but the pressurized housing of the skimmer or reactor helps prevent excess ozone from escaping. Since escaped ozone can be dangerous, it is necessary to install a carbon filter on your protein skimmer or ozone reactor at the areas where ozonized air escapes (I.E., the top of certain reactors or under the lid of the skimmer collection cup). It is also advisable to place an activated carbon filter at the outlet where the ozonized water enters back into the sump or aquarium. The ozone in the water then breaks down organics in the aquarium water and takes care of parasites and bacteria.

AIR PUMP (AERATOR): Air pumps are an older type of technology, still in use today. Most air pumps run on a vibration principle, where a flexible arm (shaft) is connected to a diaphragm. The arm is moved rapidly back and forth by electric energy, which in turn moves the diaphragm backwards and forwards. Air is sucked in on the backward movement and pushed down the airline on the forward movement. The air is usually released into the seawater through an air stone, though an air curtain can be used. The air curtain is simply a length of rigid airline with holes spaced equally along its length and blocked at one end. Different parts of air pump are shown in the following diagrams.

Air space

Air outlet

Shaft

Diaphragm Motor

- 14 -

Other aeration devices for aquaria include air blowers and air compressors. Air blowers provide high volume low pressure air and can be connected to individual aquaria of an aquarium complex by sharing through a mail air supply pipe. Air compressors are suggested for short duration air supply such as in public aquarium shows as they supply low volume high pressure air which may be contaminated with minute quantities of fuel oils.

Significance of aeration: Aeration makes the aquarium water rich in oxygen which is required for the respiration of fishes, invertebrates and plants. Oxygen in air can oxidize some of the waste materials in water. Moreover, nitrogen cycling bacteria could not survive without oxygen. All types of filters, ozonisers and protein skimmers require air for their working.

VACUUM CLEANERS: These are known otherwise as gravel cleaners. It is simple equipment with a wide-mouthed open end provided with a mesh, a long siphoning tube and an air sucking bulb. It is used to clean aquarium substrate and inside of tank walls. The open mouth can be inserted into the aquarium and gently disturb the gravel bed so that the accumulated waste can be sucked up by pressing the bulb. The waste water along with particulate matter can be siphoned off using this accessory.

Mouth

Siphoning tube

Sucking Bulb - 15 -

AQUARIUM: Water Quality Parameters

As with any aquarium (small home aquarium or large public aquarium) or pond (indoor or outdoor), a number of water quality parameters must be addressed. Each system in the public aquarium or facility with multiple ponds or glass aquarium complex must be evaluated as a separate system independent of the others. Each of the exhibits or ponds would either have its own filtration system or share one with a few of the others that have the same requirements. Water quality maintenance involves the following parameters:

Temperature Maintenance of fish in their optimum temperature range is important in keeping them healthy.Tropical species typically require water temperatures that range from 75 to 85o F. The cold-waterspecies require temperatures below 50 o F. Therefore, to maintain the desired temperature for each system, either a chiller or heater of sufficient size is needed. Extremes in temperature should be avoided (a rate change greater than 2o C increase or 1o C decrease in a 24 hour period could affect the health of tropical fish). When building a new large public aquarium exhibit that requires cold water, chiller units must be designed into the filtration component. Sometimes the capacity of chillers does not meet the demands of the aquarium. Fish exposed to temperatures slightly out of their optimum temperature range may suffer from diseases (typically infectious diseases) associated with immunosuppression. Water hardness Water hardness refers to the concentration of mineral ions in water predominated by calcium and . It is expressed in terms of (CaCO3). One degree of hardness equals 17ppm CaCO3. Soft water refers to water with 0-75ppm CaCO3 and has the lowest buffering capacity. Moderately hard water has 75-150ppm CaCO3. Hard water has 150-300ppm CaCO3 and very hard water had a concentration of CaCO3 greater than 300ppm, which has the highest buffering capacity. pH The pH of a freshwater aquarium system should range between 6.8 and 7.8, whereas, a marineaquarium should range between 7.8 and 8.3. It should be noted that an alkaline pH favors ammonia toxicity in a system having issues with increased ammonia levels. Also, an acid pH decreases oxidation of NH3 by bacteria and a pH of 4 and 5 will damage gills. New aquariums and ponds may demonstrate challenges in the adjustment of the pH because of chemicals leaching out of the new construction. Typically, the new public aquariums and ponds that are made out of concrete tend to be more alkaline requiring the addition of acid to keep the pH within normal range for the fish. and buffering capacity Alkalinity refers to the concentration of basic substances, i.e. bicarbonate, carbonate and hydroxide ion in solution. It is expressed as ppm equivalents of carbonate; therefore, in general,total hardness measurements will be close to measurements of total alkalinity because Ca and Mgare generally associated with carbonate. Water with a high alkalinity is more strongly buffered than water with a low alkalinity. In a closed aquatic system, the pH decreases because of increasehydrogen ions from respiratory processes and a pH "crash" (pH <4) occurs in soft water when all the buffering capacity is utilized. If a pH

- 16 - crash occurs, then a portion of the water should be changed and a commercially available buffer, such as dolomitic limestone, coral gravel, or oyster shell, should be added.

Chlorine Chlorine is used in municipal water supplies (usually 0.2-0.7 ppm total chlorine) to destroy pathogenic . Chlorine, hypochlorous acid, and hypochlorite ion damage fish gills. They also combine with nitrogenous organic compounds to form chloramines, which are also toxic to fish. Total chlorine values refer to the free chlorine and chloramines concentrations in water. Chlorine can be removed from water by aeration or the addition of 1% sodium thiosulfate (usually 1 drop per gallon of water). Sodium thiosulfate neutralizes chloramines; however, it releases ammonia, which is toxic to fish. Ammonia is oxidized quickly by nitrifying bacteria in established aquariums or ammonia absorbing clays (zeolites) can also be used. A lower pH (6-7) will also help to reduce toxic ammonia levels. Marine systems having a pH of 7.8-8.3 will potentially have higher toxic levels of ammonia when chloramine is treatment with sodium thiosulfate releasing ammonia. The ammonia-absorbing clays are ineffective in salt water; therefore the chlorine and ammonia should be removed from the freshwater used to make up the marine water prior to mixing marine salts. Salinity refers to the total concentration of all ions in water determined by electrical conductivity,chlorinity, chlorosity, or density of a water sample. The normal salinity for seawater is 35 ppt. Marine fish are hypoosmoregulatory, unlike freshwater fish, and osmoregulate by constantly drinking water. Chloride cells in the gills and mucus cells in the skin excrete the excess salt. Marine fish excrete concentrated urine in small volumes. Freshwater fish are hyperosmoregulatory, do not drink water, and excrete dilute urine in large volumes. Dissolved oxygen (DO) Dissolved oxygen is measured using electronic meters. A DO of 5 ppm is adequate for tropical fish. Marine systems should have DO of 5.5 to saturation (6.8 is approaching saturation for salt water). The DO decreases as temperature and salinity increase. Ammonia, Nitrite, and Nitrate or the Nitrogen cycle and nitrification: 1. Excess food, feces, plant debris, and expired NH4 from the gills produce ammonia. 2. Ammonia is converted to nitrite by bacterial (Nitrosomonas) decomposition. 3. Nitrite is converted to nitrate by bacterial (Nitrobacter) decomposition. 4. Bacteria, algae, and higher plants utilize nitrate as a nutrient 5. Ammonia and nitrite are toxic to fish. The new tank syndrome," "run-in period," or "conditioning period" refers to the period without the initial seeding of a new aquarium with nitrifying bacteria. In a closed aquatic system where fish have been added there is a period where ammonia and nitrites are elevated until nitrifying bacteria become established to remove these toxins. As a result, fish will begin to die of ammonia and nitrite toxicity (nitrites form methemoglobin from hemoglobin resulting in hypoxia) in a few days (i.e. 4-7 days) following the establishment of the new aquarium. This can be avoided by conditioning the tank with nitrifying bacteria (i.e. add 20% or greater gravel from an established aquarium or organic soil) and feeding the system with ammonia salts or urea (10ppm). Frequent 50% or greater water changes (twice weekly) may be required until the ammonia and nitrites are below toxic levels. One should avoid overstocking and feeding. Begin stocking with a few for the first two months, and then add fish slowly over time until the capacity of the system has been reached. Treatment of an aquatic system for ammonia toxicity (>0.05ppm) involves:

- 17 - 1. Water changes and addition of conditioned gravel or foam filter from an established system 2. Decreasing the pH to near 7, if the pH is above 7 to convert ammonia to nontoxic ammonium. 3. Ammonia absorbers (zeolites) can be used; however they do not remove nitrites and do not work in marine systems. Treatment of an aquatic system for nitrite toxicity (>0.1ppm) involves: 1. Water changes or removal of the fish to a healthier system will provide immediate treatment for nitrite toxicity. 2. Addition of gravel or foam filter from an established aquarium. 3. Increasing the salinity to 100 ppm (7 teaspoons table salt to 10 gallons) will prevent nitrite uptake in freshwater fish because chloride ion competes with nitrites for uptake.

Quarantine (the process of isolation of infected / infested fish from a group of healthy fishes for observation and treatment so that the disease is not transmitted to normal ones) is essential in the prevention of disease outbreaks in closed aquatic systems. It is rarely performed in home aquariums, but highly advisable. Fish should be housed in a separate quarantine tank with its own water supply, filtration, nets, etc. for a minimum of 14 days for disease surveillance. During this period, fish may be treated for pathogens (i.e. parasites) as a precaution.

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AQUARIUM LIGHTING

Significance of : Light is an essential requirement for all aquarium inhabitants including fishes, plants (including algae), invertebrates and some of the bacteria. Controlled lighting is necessary in maintaining the ecological balance of an aquarium set-up. It is very essential for aquarium plants (primary producers) for photosynthesis and they release oxygen so that it will dissolve in water. All organisms have their respective light period (time for which light is available during the 24 hr period) which makes them healthy. Reproduction of many fishes and ornamental invertebrates is sensitive to presence or absence and intensity variations in light. Moreover lighting adds to the beauty of the aquarium. Suitable lighting can greatly enhance the attractiveness of aquarium inhabitants. Proper lighting arrangements are necessary to suitably highlight the decorations in a professionally-set aquarium.

A commonly asked question is: how long should the aquarium lights are to be switched on each day? Since most of the inhabitants and plants for aquaria come from the tropical regions of the world, it is best to mimic the day-length of this region. Length of daylight varies little seasonally in tropical areas. Generally, the light period is 12 hours with an intense period of 9 to 10 hours. Keeping lights on for over 10 to 12 hours per day is of no practical benefit and can cause algae blooms. It is best to buy an inexpensive timer and automate the light system.

Another common question is how long will the lamps last? Usually lamps should be changed before they actually stop emitting light. The reason is that the color spectrum of a lamp changes as the lamp ages. While the lamp may still light, it does not emit light of the original wavelength. A common problem is for the hobbyist to use a lamp until it

- 18 - no longer radiates light. Lamps should be changed at least once a year, but preferably every 6 to 8 months. If nutrient levels in the tank are in safe limit, algal growth can be attributed to change in spectral quality of lighting. If it was over 6 to 8 months, consider that the lamp's spectrum may have shifted and the lamp needs changing.

Fish-only tanks can have a very simple light system. The purpose is to show off the fish and tank setup. The final decision depends upon the individual taste of the hobbyist. For 20 gallon tanks and under, one is adequate. From 30 to 55 gallons, two lamps, minimum, should be used. Add an additional lamp for each 20-25 gallons of water capacity. A lamp with a 5,000 ¡K to 6,000 ¡K is recommended, but many hobbyists prefer lamps which emit more red color as they can show the fish colors better. This is fine, but these types of lamps will not promote the growth of plants.

Plant tanks require the correct lighting to be successful. The number one reason for lack of success in growing plants in an aquarium has to be the use of the wrong lamp. Plants have two types of chlorophyll, a and b. Chlorophyll a absorbs light at 405 and 640 nm. Chlorophyll b has peak absorption at 440 and 620 nm. Plant lamps are designed to emit light at the red wavelengths to duplicate the job of the sun. But too much red color can cause aquatic plants to grow tall and thin. For best results, use a daylight (5,000 ¡K) lamp with an actinic white or actinic day lamp. The actinic day or white lamp is a mixture of 50% actinic (blue light) and 50% daylight. In large or deep aquaria consider using HO (high output) or VHO (very high output) lamps.

To have a successful reef aquarium, adequate light is absolutely required. Reef tanks contain soft and hard corals which harbor zooxanthellae. The zooxanthellae (symbiotic algae) must thrive in order for the coral to live. To do this they need the correct amount of light (intensity) at the right wavelength (peak absorption).

- 19 - LAMP TYPES:

I. METAL HALIDE LAMPS: Metal halide aquarium lighting is the lighting of choice for many reef . Metal halides produce more lumens per watt than any other aquarium lighting source. They emit excessive heat making a chiller necessary in most cases. The basic components used for all metal halide aquarium lighting systems include: Metal halide lamp, Ballast, Lamp socket and mounting bracket and Reflector.

II. FLUORESCENT LIGHTING There are four main types of fluorescent aquarium lighting: 1.Compact Fluorescent lamps (CFL): Compact fluorescents, sometimes called power compacts, are brighter and more energy efficient than normal output fluorescent bulbs. 2.Normal Output (NO): Normal Output bulbs are standard wattage bulbs that usually come with many stock aquarium hoods. Normal Output bulbs come in varying lengths, including but not limited to, 18", 24", 36", 48", and 72". 3.Very High Output (VHO): Very High Output bulbs allow you to fit fewer bulbs over your tank and provide considerably more lumens as compared to NO bulbs. All VHO bulbs are 1.5" in diameter (T12). VHO's, like all linear fluorescents, distribute the light evenly across the water surface, unlike Metal Halides which is a single point of light. Another advantage to using VHO lighting is that they generate less heat as compared to Metal Halides. VHO bulbs generally will need to be replaced about every six months, or as according to the manufacturers’ recommendation. VHO bulbs require a 1500ma VHO ballast to operate. 4. T5HO High Output: All T5 bulbs must be run on electronic ballast. T5's have a higher lumen output than a VHO, generate less heat, and are more energy efficient. It has also been reported that T5's last considerably longer, between 2-3 years, with less degrade in lumen output. At only 5/8" in diameter, more bulbs can fit under the tank’s roof. With all linear fluorescent lamps, the wattage always increases as the lamp length increases. The main factor to consider when selecting aquarium lighting is the photosynthetic requirements of the aquarium inhabitants and aesthetics, while color spectrum and lumen output will have the most significant impact. Normal output, also known as standard fluorescent lights, is generally suitable for fish only aquariums and will not provide enough photosynthetically active radiation to support robust and vigorous growth. For plants and that use photosynthesis as their source of energy you will want to consider using compact fluorescent, very high output T12, high output T5, or metal halide lamps. Aquarium fluorescent lamps are labeled according to the diameter, for

- 20 - example T5, T8, or T12. The number following the T refers to the diameter in one-eighth inch increments.

III. LED LIGHTING LED is an acronym that stands for Light-EmittingDiode. LED lighting is low voltage, energy efficient, long lasting, and produces relatively little heat and consists of small diodes attached to a circuit board. Commercial LED fixtures are available in a wide variety of options including single pendants, light rails and tubes, complete fixtures, and flood lights design to fit a standard screw- in socket. LED diodes are available in a wide range of colors enabling endless color combinations to create almost any spectrum desired. LED aquarium lighting can be broken down into two categories: the first is moonlight simulation and the second is daylight spectrum used as either primary or supplemental lighting. Moonlight simulation can be accomplished with a small number of blue LED's. Usually only one or two LED's per square foot is all that is necessary to achieve the night time affect. LED moonlights can be placed on a timer turn nightly during the dark period. Some aquarists get more sophisticated by using a programmable timer that allows for a 28 day moon cycle and having the LED moonlights turn on for only one week of the month to simulate a full moon.

IV: INCANDESCENT LIGHTS: Incandescent lamps with a wattage of 7-25 only should be used in aquaria as they emit a lot of heat. They should be changed every 2-4 months to keep the spectral quality of the lighting. They are of narrow spectrum and low light intensity. Brilliantly colored species may look more attractive under this type of lighting arrangements. They are suitable for a beginner hobbyist.

REFUGIUM LIGHTING: Most commonly used with saltwater aquariums, a is a separate enclosed space that shares the same water supply as the main tank.A refugium serves as a place of refuge for microfauna such as , amphipods, mysis shrimp, and isopods that is free from and invertebrates.

ACTINIC LIGHTING Actinic lighting peaks in the 420 nanometer range and emits a fluorescent blue light and is usually used as supplemental lighting. Not only is actinic lighting beneficial to photosynthetic invertebrates, it is also aesthetically pleasing to the eye when used to supplement daylight lighting.

- 21 - Food and Feeding of Aquarium Fishes

Like all living species, fish too need nutritious food. Different fish species require different food types. The feeding of fish and their nutrition is one of the most important factors in keeping them healthy. Since fish are very diverse in their habits, there is a large diversity in their eating patterns also. Obviously, a single type of food will not be enough to meet the requirements of the fish. That is why many of the exotic varieties of fish shouldn’t be maintained in an aquarium by anyone but an experienced aquarist. Most of thefish that have adapted to aquarium life can be trained and habituated to eat different kinds of food. The first step is that the fish has to be able to recognize food. Even the most nutritious of food goes to waste if the fish does not understand that it is to be eaten. Both instinct as well as training affects this recognition. Hunger is not the only thing that leads a fish to food. Security as well as good health is also necessary.

Upon introduction into its new home, a fish may not take to its food right away. If an aquarium does not resemble its natural habitat or is completely devoid of friendly objects like plants, the fish may feel insecure. Sometimes, the temperature in the aquarium is just not right, or the intensity of the glare coming from lights can be too harsh. Dimming lights a bit until the fish get used to the lights will rectify the problem. Various visual and chemical clues point out the food to the fish. Once the fish has located the food, it may taste it before it accepts the feed. Some fish may take in the food, and regurgitate it if they feel that it is not acceptable. Predatory fish have a different kind of feeding pattern. Generalizations about the sensory characteristics of diverse kinds of fish will therefore not be accurate or appropriate, but here are some general traits in food that can attract fish.

Flavor and taste This characteristic of food is especially important in case of bottom feeders. Smell can be detected by the specific anatomical receptors in fish, but flavor has to be dissolved in water for the fish to locate it. Some fish have receptors in their mouths, or on the head or lips. Some even have taste receptors on their skin. These receptors carry messages to the brain and tell the fish to swim towards the food. Some kinds of food can strongly stimulate fish to feed by their flavor, but these stimuli need not be the same as in humans. Therefore, it will be better not to give the fish sweet and fatty food. Sound Through water, sound travels about four times faster than it does through air. So, a fish can actually "hear" sound through the vibrations that take place in water. By picking up these vibrations in water, the fish become aware of the feeding frenzies that cause many fish to conglomerate when the feeding begins. Also, there are fish that are so used to a routine in their feeding that they start grouping when they hear sounds that normally precede feeding. Smell The sense of smell is highly developed in fish. In nature, fish needs to be able to identify their food and also their mates through the sense of smell. So, many fish species have nostrils that help them to identify the various things they come across. These sensors thus help the fish to zero-in on their food.

- 22 - Color and Buoyancy of food Some fish that are used to feeding on floating food may not take to food that has sunk to the bottom. Similarly, bottom feeders rarely come to the top of the aquarium to eat food. A majority of the fish species in the tropical variety are however not very picky when it comes to the buoyancy of food.

Understanding feeding and digestion in fish

Feeding the fish with the right kind of food at the right time and in the right amounts is crucial to their growth and development. In a closed system, the fish have no choice but to eat what they are provided with. If you want fish that are full of energy, you have to feed them according to their particular needs. Every type of fish has a specific feeding requirement. Herbivorous fish require lots of fiber in their diet, while carnivores require food that is rich in protein. Some predatory fish eat food only after chasing the live food.

When compared to humans, the digestive system in fish is relatively simple. Carnivorous fishes have well-developed stomach that secrete abundance of protein and fat digesting enzymes. Herbivorous individuals possess elongated intestine and are adapted for efficient protein and carbohydrate digestion.

Fish also gain unhealthy fat from over eating. Some fish like the will eat just about any amount of food. They become too big and lose health. One should remember that fish in an aquarium do not expend energy looking for and chasing food. They only move about within the confines of your tiny little aquarium. So, feed the fishes only according to their nutritional needs.

Overfeeding introduces a lot of unwanted toxins into an aquarium. Mostly, fish are able to take in the food they need within 5-10 minutes of their feed. Food left in the aquarium after the first 10 minutes of feeding is not needed by the fish, and will collect in the aquarium as waste; decaying and releasing toxins.Give fishes a variety of food. Feeding fish the same kind of food day after day tends to dry up their appetite. Besides, they also need a variety of nutrients, which can be provided only by rotating the feed.

Live feed should be introduced into an aquarium with utmost care. Many fish species love worms, insect larvae etc. and will stay much healthier when provided with live food. Care must however be taken to ensure that these food varieties do not carry infections, such as germs or other parasites, in them. This is very difficult to ascertain, unless a hobbyist culture his own live food.

Food for the fish has to encompass a large number of nutrients. All these together make fish healthy and able to adapt to changing conditions in the aquarium. The essential nutrient components required in aquarium fish feeds are the following:-

1. Protein Protein is the single most important nutrient that the fish needs to grow. On a dry- weight basis, this makes up the maximum weight in their body structure. Amino acids are derived from proteins and the fish uses them to make new body tissues as well as enzymes. Fish are very adept at converting food to body tissues. That is why fish need

- 23 - lesser amounts of food than do most other animals. Carbohydrates are almost nonexistent in the food intake for many fish species, since energy is also derived from proteins. The quantity of protein required for the fish to be healthy depends on a number of variables like the species of fish, amount of natural food available, growth rate etc. Fry and larvae require a more protein rich diet to maximize their adaptability and chances of survival. As the fish grow larger, their dependency on protein reduces. The temperature of the water also affects protein requirements.

2. Fatty acids Fatty acids are a storehouse of energy for most fish. They provide stamina. Carbohydrates can also do this job. It is also seen that some of the predatory fish species require some source of fish oil in their diet too. Fish that live within the confines of an aquarium are naturally prone to obesity. They do not use up their excess energy in swimming long distances or looking for food. In most cases, excess fat can be damaging to the general health of the fish. Some fish lose their reproductive capabilities if there is too much body fat.

3. Fat-soluble carotenoids Fat-soluble carotenoid is responsible for the bright hues in some fish. and brine fish are some of the foods that are rich in pigments.

4. Carbohydrates Carbohydrates make up 20-30% of the common commercial foods. While they are alternate sources of energy, they are not very necessary for fish growth. Though most fish will handle some amount of carbohydrates, they develop signs of ill health if there is a high concentration of carbohydrates in their diet. For instance, if young fish ingest too much of carbohydrates, other nutrients will not be absorbed appropriately by their bodies. That is why cereal grains, which have very high levels of raw starch, are not ingested fully by fish. 5. Vitamins and minerals Vitamins are vital to fish health. These are organic substances that act as catalysts for many of the biochemical reactions within the fish. Almost all vitamin deficiency will increase the fish's susceptibility to diseases and stress. The best way to get a rich supply of vitamins to your fish is to buy small quantities of diverse food for them. Storing excess food in the freezer also prolongs the life of the vitamins. Providing frozen or fresh vegetables and live food can also supply the much-required vitamins to your fish. Minerals are also necessary for you fish. Bones, teeth and scale tissues require lots of minerals. The minerals also carry out many supportive functions. Your tropical fish will most likely suffer from a lack of Calcium and Phosphorous, if any. If they are kept in hard water, fish are able to extract some amount of calcium from it, but soft water has absolutely no supplies of calcium. Though mineral supplements will help to compensate this deficiency, excess of some minerals can be poisonous. Therefore, mineral supplements should not be used indiscriminately.

Feeding Habits There are three basic eating groups among fish: carnivores, , and omnivores. A fourth but minor category called detritivores is there which feeds on decaying organic matter like organic mud settling at the bottom. Each group of fish needs to be fed in a particular way.

- 24 -

Carnivores are meat-eating fish. Whilst they will never damage plants in an aquarium, they may eat upon small fishes. Carnivores need at least 45% of protein in their food, without which they become severely malnourished. Although many of the prepared foods are spiked with extra protein to help such fish, carnivores are happiest when they are fed live food like worms. An added benefit is that chasing their prey seems to stimulate their appetite even further. Recommended food for the carnivores would be: Earthworms, Red worms, Tubifex worms and , larvae of mosquitoes or fruit flies, Oysters, shrimps, clams and other fish. If these are kept frozen, they need to be thawed and then sliced into slice. Chicken can be given to bigger fish, but these should be cooked, but never fried.

Herbivorous fish are those that will eat only plants. These fish need to graze very often, and whether they are fed regularly or not, they will nip at plants. It is a good idea to feed these fish with fresh veggies or plant the aquarium with moderate number of live plants.. Planting leafy vegetables like spinach into the substrate is a good trick. The fish will keep nipping at these. Vegetable flakes come in a variety of flavors. Algal flakes will also be a favorite among this kind of fish.

Omnivore fish will eat pretty much anything, and that makes them dangerous to plants as well as to other smaller creatures in your aquarium. They are also voracious eaters and aquarists can sometimes mistake their eating frenzy for hunger. It is a common tendency to overfeed these species, and they do tend to pile on the fat very quickly if overfed.

Detritivores are constantly eating, and can be given pellets and algae based foods.

Types of food Most commonly, fish food can be divided into 3 main categories:

1. Manufactured (prepared) food: This includes floating and sinking pellet, granular and flake food.

2. Live foods: Brine Shrimp (Artemia), Maggots, fresh insect larvae, live worms, and - all come under this category.

3. Frozen foods: A mix of vegetable matter, meat, small animals as a whole etc.

1. Manufactured (prepared) food: Flake food refers to a kind of food that is most commonly eaten by both marine as well as tropical freshwater fish. This is ideally suited for top dwellers and mid-water fish. Once the flake food has settled down, it can be eaten by the bottom dwellers too. If an aquarium consists of bottom dwellers mainly, it would be a good idea to pre-soak the flake food so that it will sink to the bottom as soon as it is introduced into the water. Flake foods have evolved over the years and come much closer to providing all essential nutrients for fishes. They are an excellent source of various minerals too. They are easy to keep and have fairly long shelf lives. They come in various flavors. One can even get different kinds of flakes in one can. This is a great way to feed wholesome food to the fish. Drop a pinch or two of the flake into the water and observe the rate at which this is eaten. Then decide how much needs to be put in the next feeding. For vegetarian fish,

- 25 - there are vegetarian flakes available, such as algae flakes. One serving of algae per day is enjoyed by almost all fish except for predatory fish. For the bottom feeders, the aquarist should go in for algae wafers and discs. If a disc has not been eaten within 24 hours, it has to be removed otherwise it will start putrefying in the aquarium, and releasing toxins. An unfortunate truth about flake food is that the nutrients in the flake food get deteriorated quite quickly. So it should not be stocked in large quantities. Always buy more than one variety and rotate your feed. The fish too get bored of eating the same stuff everyday. A good flake food is one that meets the needs of most of the fish in a . If you have larger fish in your aquarium, they will prefer to eat something larger than a tiny flake. After all, they have larger mouths, and naturally, they'd prefer to eat something bigger. Sinking or floating pellets are therefore a better choice for larger fish. Pellets come in various sizes and shapes, suited for fish of different sizes. Granular feed needs to be used only if your bottom feeders are not getting enough sunken flakes or seem hungry. Bottom dwellers often need to be fed separately, so granular food is ideal for this kind of fish.

Besides flakes and pellets, there are also freeze dried foods like Tubifex, krill and river shrimp. 2. Live feeds Despite the variety, flavor and popularity of the various prepared food available in the market, there is still a need to feed aquarium fish some varieties of live feeds. Live feeds add a lot of nutrients that may be lacking in prepared foods. Live food needs to be handled with a bit of caution. They should not be decayed or infected. Maintaining a live feeds culture at home ensures its purity, quality and lack of chemicals and contaminants.

Planktons are minute floating aquatic plants and animals. They are a good source of nutrition for fish. can be trapped or netted from ponds for feeding. Tubifex worms are a hot favorite among a large number of fish. They are unfortunately also known to carry diseases and are very fatty which means that Tubifex only should be used occasionally. Rinsing out live food thoroughly before introducing it into water will greatly help reduce the chances of carrying the disease into the aquarium, but this method is naturally only effective for the germs outside the body.

Microworms are one of the simplest fish foods to culture. These are primarily used to feed fish fry. Fish that are too small to feed on brine shrimp will find these an excellent choice.

Brine shrimp, on the other hand, are minute shrimps collected from saltwater ponds. Even after they are dried, they remain dormant inside cysts. These cysts can be hatched as and when needed even after storing them for months and even years. Each cyst will contain one single animal.

Earthworms and redworms are other popular sources of food for tropical fish. These are easy to rear, but are also high in fat content. They are very popular among some fish varieties like the .

Cultivation of some common live feeds: Earthworms are some of the most complete sources of food in nature. These worms are full of vitamins, roughage and calcium. They have rich supplies of proteins too. Fish that are fed on earthworms grow at a very fast rate. Large fish like the Cichlids

- 26 - will eat the adult earthworm in whole, while medium size fish will eat worms that are an inch or less in length. The very small fish species will need the worms chopped or shredded. Earthworms are blind, but light sensitive. They will burrow into the soil to avoid light. They are also temperature sensitive, and will drown if their home is flooded. Earthworms prefer a rich, clay free soil. You can feed them with decaying vegetables and eggshells. The simplest way to culture a small quantity of worms is to gather some very heavy sacking on the ground. This should be in a shady spot. The area should be kept moist. Some scraps of vegetables should be placed in between the sack and the ground to encourage the growth of the worms. When you need the worms, just lift up the sack and remove the worms that cling to the sack.

Microworms are fairly easy to cultivate too once you get a fresh starter. Transfer the starter culture to a large container. Maintain a temperature between 65-75 Farenheit. Prick small holes into the lid for air exchange. Any cereal-based media, including cornmeal or oatmeal or even baby food, can be used for the microworms. Mix about one spoon of brewers yeast to the culture. The yeast should be mixed in slightly warm water. In 3-5 days, we can see that the worms have filled the surface of the medium and will start climbing over. These can then be collected using an ice cream stick. Rinse the worms, and then feed the worms to the fish using a baby eyedropper. One excellent side benefit of culturing microworms is that we can add liquid vitamins to the culture. Whatever we feed the worms will go directly to the fish too.

The larvae and adult specimens of fruit flies are another hot favorite among fish. Cultivation of maggots is best suited for the summer months. Make a few holes in a plastic container. These holes should be big enough for the flies to enter. Make some smaller holes at the bottom of the container, and place a small piece of fish or meat within the container. Place this in a large container and put it in a shady part of a garden. Within a few hors, flies will start visiting the container and would have laid their eggs on the bait. After a few days the larvae will start coming out of the inner container. These can then be collected and fed to the fish.

Water fleas or daphnia are an excellent supplementary food. They can be given once every week to the fish. They are a rich source of fiber. A starter culture of Daphnia can be store-bought or captured from the wild. Take a shallow container, clean it thoroughly and fill it with alkaline water. The container should receive plenty of sunlight, but not left exposed to the sun all day. Now, add the fleas. Various substances like rotting lettuce, green water or yeast can be used as food. Do not add too much of food, since the water will foul up and the fleas will die due to a lack of oxygen. Gram flour is one of the best substances for food. Mix the flour well with half a liter of water. Add this mixture to the culture. The culture will look cloudy now, but the bottom of the container will still be seen. Within a week, the container will be filled with fleas that can be netted and fed to the fish. Daphnia are sensitive to the presence of other life forms in their water, and even algae should therefore be kept out of the medium while culturing Daphnia.

Brine shrimp is another excellent food for fish. They are available in 3 forms: live, frozen or freeze-dried. The eggs of the brine shrimp are easily available for home cultivation. The shrimp that come out of them are excellent food for fry, while adult Brine shrimp can be fed to adult fish (and to very large fry). The exoskeletons of the Brine shrimp are excellent sources of fiber.

- 27 - Cyclops is another tiny animal that can be cultivated at home and that is a good food for large fry and small fish. Cyclops cannot be used as food for small fry as they attack the fry.

Insect larvae of Bloodworms, White and Black Mosquitoes, and Meal Worms are also good fish food. The larvae of black mosquitoes are especially good as they are full of vitamins. In some fish species, these seem to trigger the spawning process. Mosquitoes can easily be bred in standing water, and their larvae can be caught and fed to the fish. Flies, Crickets, Back swimmers and Beetles can also be caught easily and fed to your larger fish. Several types of mollusks, including , can be used as food for larger fish like the Puffer fish. Goldfish and guppies are widely used as feeder fish. Larger species relish these, but feeder fish can be carriers of diseases or infection. Proper care should be taken before using them as food.

3. Frozen foods: Any type of feeds including a variety of live feeds described above and plant matter or a mix of both can be frozen by keeping in refrigerator or deep freezer. At the time of feeding they can be taken out and thawed (de-freezed) and supplied to fishes.

Feeding Fry Newly hatched and just into the aquarium, fry are indeed very small and helpless. They need to be maintained with much care in order to see them safely into adulthood. They need excellent water quality and extra security, as the fry are often delicious food for the other carnivores in your aquarium. It is often a good idea to enclose the fry separately, but some fry require their parents to care for them. Usually, small sources of food suffice for fry. Live foods almost always give the best results because growth rate in fish is noticed to be at least three times faster when they eat live food.

Prepared mixes may also be used to feed fry. These mixtures are usually flake- based food that has been ground to a very fine powder. The obvious problem with this is that it quickly pollutes the water. Fry are often too small to be in an aquarium with vigorous filtration, and without filtration the water quality goes downhill very soon. Liquid mixtures tend to settle at the bottom of the aquarium, and fry are normally surface feeders, so a lot of the food does not get to them.

Infusoria are a good choice for feeding the fry of aquarium fishes. refers to the various microorganisms that are present in small quantities in the water. This can be cultured and introduced in small quantities to feed fry. Just like many other types of food, Infusorians is potentially dangerous to the fry as infusorians can foul up the water and make it toxic.

Newly hatched Brine shrimp is an excellent source of food for fry. You will be able to purchase Brine shrimp eggs from your local pet store. Take a plastic bottle; add water and one tablespoon of coarse salt to two teaspoons of brine shrimp eggs. The temperature should be around 80 Degrees F. Sufficient aeration is important. The eggs will start hatching in 24-36 hours. It is advisable to stop the aeration at this point. The Brine shrimp will settle at the bottom while the eggshells will rise to the top. Siphon out the young shrimps into a fine net, rinse thoroughly and feed the fry.

- 28 - Green water or suspended algae (e.g. Chlorella, Spirulina etc.) can easily be cultured at home. Take some aged tap water and leave it in a sunny place. Remember to add some algae from your aquarium as well as a few drops of plant fertilizer to this. The algae will develop in 2-3 days. Use an eyedropper to feed this to the fry.

Egg yolk prepared at home can also be used to feed fry. After you hard-boil an egg, take a small piece of the yolk and put it in a cloth, roughly 10cm by 10 cm in dimensions. Fold this into a bag, and screw the bag so that a bit of the yolk protrudes out from the bag. Dip this bag into the aquarium to feed fry. The yolk needs to be replaced in 2-3 days, otherwise it will spoil.

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