Tropical Aquarium Fish

The genus is spread all over the south-east Asia, it belongs to Belontiidae. They are burly, slender, strong and flank oblate fish. They have a short mouth with marked lips. The dorsal fin is equal or bigger than the anal fin. The first ray of the pectorals fin is very prolonged, sometimes it`s even forked. The middle, superior or inferior rays of the caudal fin can also be very prolonged. The lateral line is incomplete or it is absent completely. They are very resistant fish but only the youngsters are friendly. In general, the can hardly endure the presence of other species in the same aquarium. They eat both alive food, which they prefer, and dehydrated flakes. They prefer sunny aquariums or an aquarium with lot of light. It`s better to avoid introducing them in new aquariums or in much planted aquariums.
Macropodus opercularis are long body fish, with very oblate flanks especially in the back part of the body. The males can reach 8 cm, females are a little smaller but with a big abdominal are (especially after sexual grow). The colors of the body can change because the fish are restless, especially males when they feel the presence of another male from the same specie. When they are excited, the color of the body looks like this: a blue-shining green background with transversal red lines. When they spawn, the males have the head and abdominal area colored in velvety black, the fins are from blue to red with another nuance blue lines. The male is more colored than the female and its lips are more marked.
Macropodus opercularis are spread from Korea to China, Vietnam and Taiwan where they live in stagnant or slow flowing waters. They were first introduced in European aquariums in 1869 and their first reproduction in captivity has been realized by Carbonnier. First Alfred Gunter and Boulanger thought they are artificial created fish, but Kreienberg proved they are not. He observed that the Chinese don`t keep them in aquariums and don`t even sell them like other species (selected goldfish).
A variant of Macropodus opercularis is Macropodus opercularis concolor. They are easy to breed fish; the temperatures can vary from 15 to 30° C and the minimum temperature can be 10° C.

Macropodus opercularis concolor doesn`t have the transversal lines, the only difference is that Macropodus opercularis concolor becomes almost black in the reproduction period and its fins are very prolonged. Their reproduction involves the building of a bubble nest, a particularity of the family. The water level in the reproduction aquarium doesn`t matter because the eggs are very oleos and they remain in the nest under the supervision of the male. Their reproduction is very similar to Tricogaster trichopterus and you can find more information there.

Origins of diseases
The origin of a disease can be external:
- adding in the aquarium a stressed fish during the transport from a country to another, or from a pet shop to home; a disease can occur and it can spread to other aquarium fish too
- adding a disease carrier fish or a sick fish
- adding polluted water from nature
- accidentally adding toxic substances – smoke and others
Of course, you have to be careful in order to avoid all these situations. The diseases can also have internal origins, because of the perturbation of the general equilibrium from the aquarium, which activates the diseases to carrier fish:
- the decrease of the temperature, or temperature shock, sudden variations of temperature in both senses (+ or -), induced by an injury at the heating system
- the decrease of the oxygen level
- over flow of nitrogen substances, caused by an injury to the filtration system of by the big number of fish in the aquarium
- the general quality of the aquarium water
- wounds suffered during a fight or during spawn, or caused by hitting the décor
- bad feeding or incorrect equilibrated feeding
- the presence of plants under decomposing

The prevention of diseases
It’s better to prevent a disease than to heal it, it’s an old saying valiant in aquariums too… Prevention of diseases means a daily observation on the fish and aquarium environment, some knowledge being needed. The best prevention way is maintaining the aquarium equilibrium as better as possible.

Diseases and their treatment
Globally, there are 2 kinds of aquarium fish diseases: infectious diseases and non infectious diseases. The first ones are induced by microorganisms, like bacteria, fungus or viruses carried by aquarium fish. The activation factors are well known: stress, miss alimentation, decrease of the temperature. Some pathogen organisms have a mixed life: a part in the fish body and another part in the aquarium environment.

Non infectious diseases are not induced by pathogen organisms, but by the polluted environment and lack of needed substances, you’ll have to avoid the mixture of medicine or their over administration, because they are useless and in most cases bad for the fish. You’ll have to respect the period of treatment even if the symptoms disappear. Anyway, you’ll have to focus on the fish’s health for its entire life. During the treatment of a disease, the feeding must be equilibrated and it must contain natural elements. After healing, you’ll have to administrate vitamins and minerals in order to make it stronger and improve its general condition.

Diets and food needs

By their diet, there are 3 kinds of fish:
- carnivorous fish, which eat insects, worms, shell-fish and other small fish
- herbivorous fish, which eat vegetables (plants or algae)
- omnivorous fish, which have a much diversified diet because they eat both vegetal and animal food.

It`s hard to define the diet. In nature, fish eat what they can find. That way the herbivorous fish eat sometimes small insects which can be found between the plants. The carnivorous fish especially need proteins and lipids, the herbivorous ones need especially glucose and the omnivorous fish need all 3 kinds: proteins, lipids and glucose.

These 3 diets can be found at aquarium fish too, with some exceptions. You shouldn`t forget about the vitamins and minerals which should be provided by a healthy diet. A diversified food provides the necessary elements for a good growth and breed, and also it helps preventing the diseases. In conclusion, diversified food helps the equilibrium from the aquarium.

Intake

There is a temptation of over feed the fish, resulting fat ones. This way, the risk of polluting the environment increases (a fish eating a lot will produce a proportional quantity of excrements).

An adult fish can only eat 1-2% quantity of its body weight in one day, and double if it is young. The plants are very light, they don`t present the risk of over feed, and the problem is only with the other foods. It`s recommended to program the food over the day; 2 times for adults and more times for young ones.

Fish can easily handle short periods of hunger, because of the probability that in their natural environment could be the same conditions of less food. Some aquarium fish breeder set a day in the week when they don`t feed their fish, just in case of over feed in the other days. Young offspring can suffer if they are not fed, causing them low development.

Artificial food

It`s about dry food sold out in aquaria markets/shops. They have diversified a lot in the last twenty years. Nowadays there are lots of food sets for each class of fish: fry and adults, freshwater fish and saltwater fish, etc… These foods are rich in proteins (40 to 50%) and have different forms: dehydrated foods (the most common), tablets or met feather shot. The dry food floats for a while, and then it submerges facilitating the feeding of surface and middle depth fish. Met feather shot submerge faster facilitating the feeding of middle depth and bottom fish. There are more sizes for the foods, depending on the size of the mouth. Artificial food is fragile; it degrades if it is kept in inadequate spaces. They must be kept in dry and darken spaces and it`s better to buy a medium size box if we have few fish…

Some of the tropical fish breeders feed their fish with trout food which they get from piscicultural farms. These foods, rich in lipids, favor a fast grow of the trouts which are breed for human feeding , but which is not the essential scope of aquaria. Even if these foods contain pigments which are used to color the skin of trout, the aquarium fish breeders who used them say they didn`t notice any coloration of their fish skin. Anyway, this kind of feeding is economic at industrial scale or for garden ponds.

Sometimes, the marine fish permanently or a certain period, refuse the artificial food after they are introduced in aquariums. A solution for this problem is administrating both artificial and natural food and, in time, reduce the quantity of natural food.

Frozen food

Fish can be fed with frozen shrimps, fish, worms, plankton after they are selected and cleaned. Their nutritional value is very high because the freezing doesn`t change their composition. They are kept in the refrigerator and they don`t need refreeze after defreeze. This kind of food is quite expensive in comparison with other kinds of food.

Home made food

In this last category, we have foods which can be administrated fresh or after freezing and defreeze. You have to avoid red meat and too greasy meats. Beast heart, rich in blood and lipids, will only be used for big fish. White meats are preferred: chicken, turkey, ham. From marine, we can use white fish, mollusks, shells, shrimps, which we can buy as tinned. Vegetal foods are needed for herbivorous fish because these aliments are rich in vitamins and minerals. We`ll use salad or spinach which has to be boiled for a few minutes.

Vitamins

Vitamins are very important for fish feeding as for human feeding. They have a use in skeleton developing; they help the growing and strengthen the resistance to diseases. A tropical fish which suffers of a vitamin lack will weaken, and this thing isn`t visible at the beginning. The vitamins degrade under the action of heat, oxygen and light. That`s why the main intake will be made by fresh foods, living food or frozen foods.

Dung worms

Actually, they are not worms but aquatic larva of different mosquito species. They are known as fishing bait. Contrary to their name, they don`t live in dung but in the water from areas which are rich in organic materials. You don`t have to look for them because you can find them in aquaria markets/stores. They are kept for a few days in newspaper wet paper in the fridge. They are good foods, rich in proteins, much appreciated and looked for by all aquarium fish.

Tubifex worms

These worms are taken from ooze which is rich in organic materials. Some tropical fish breeders consider that these worms represent a risk for the aquarium, because they can bring in unwanted bacteria. This risk remains limited because there haven`t been reported any severe accidents. The worms which can be found in shops are kept in fresh water for a few days at low temperatures in the fridge, but it`s very important to change the water daily in order to avoid their degradation. They are much appreciated by most of the aquarium fish.

Shrimps

In well oxygenated freshwaters there are some small shrimps with a size of 1-2 cm which swim laterally. These are the freshwater shrimps. Rarely are they sold alive, but they can be found in aquaria shops. Even you can catch them and give to the fish which appreciate them very much. There are some saltwater shrimps in the Romanian part of the Black Sea, which are appreciated especially by saltwater fish. Sometimes, they are sold at the fishing stores from the sea side. The ones who live in those are can catch them and keep them in aquariums with oxygenated saltwater. These two kinds of shrimps can be boiled and rinsed out with fresh water and after that you can mix them in order to obtain a home made food.

Small fish

For feeding marine fish, which refuse artificial foods, or big freshwater fish, we can use small fish. For doing this, some fish breeders with better experience breed prolific species, which reproduction is done easily in aquariums (Poeciliidae for examp…)

Plankton foods

Freshwater planktons or saltwater planktons contain multiple organisms which can hardly be seen (0.1-1 cm), but interesting for feeding our aquarium fish, especially the fry. In natural environment there is a big quantity, but there is a risk of bringing microorganisms that induce diseases in the aquarium. Some planktons can be found for sale in aquaria shops/markets.

Breeding baby brine shrimp (Artemia salina)

Dry eggs (called cysts) can be found in aquaria shops/markets. They must be kept in dry and dark places. In order to hatch, we`ll have to prepare saltwater with a temperature of 25° C, 3.5% salt, a density of 1023 g/l. The water can be natural, with special salt for aquaria, or you can use normal salt (easier if you don`t have marine aquariums). The water can be colder and less salty (20° C and 2% salt, density 1014), but the percentage of hatching is lower (50-60% in comparison with 80-90% if the first conditions are realized). We can use any plastic or glass tank with a small volume, though there are specialized tanks in aquaria shops. The eggs must be kept in calm water for a few minutes in order to re hydrate them. Knowing that 250.000 eggs weigh about 1 g, a small quantity is enough for breeding artemias for a generation of fry. The water is agitated with an air pomp which generates bubbles.

A big pressure will throw the eggs on the laterals making their hatching impossible. The hatching takes place in 24-36 hours at a temperature of 25° C, and 48 hours at a temperature of 20° C. At this moment you`ll have to stop the air pomp. The shells will float, the unhatched eggs will submerge and the artemias will swim at medium depth. In order to give the artemias to fish we can put all the artemias together using a pocket lantern. Artemias can live in freshwater just a few minutes. In the first day artemia doesn`t eat. You can feed your artemias with specialized food from aquaria shops and you can have adult artemias.

Paramecium

They are unicellular microscopic organisms. They represent a small quantity in the aquarium. Riccia, a floating plant, permits their developing because they can find food on the plant`s leaves. You can also get paramecium if you put some old aquarium water in a tank and introduce there salad leaf or paddy rice (unpeeled rice available in specialized shops from larger cities). The paramecium represents the perfect food for the fry.

A marvel food for fry

It`s about the yolk of egg, boiled, firm and put in a glass of water. Some micro particles form, which are get through a sifter which keeps the big particles. This soup is given to fry making sure we don`t pollute the aquarium. The yolk of egg, rich in proteins and lipids, can supply other foods. This food is very nourishing and it is indicated to all tropical fish breeders.

What can we do if a fish doesn`t eat?!

Sometimes it may happen that a fish refuses the food or can`t eat it. We have to search and cross out the cause. A new fish, recently introduced in the aquarium rarely feeds from the first day: it`s a normal fact because it feels lost in the new environment. The small species and the less active fish are dominated by big and active fish while wee feed them. In this case we have to feed them separately, better with small living food, after we distract the other fish attention with other foods.

A fish can refuse the food because it has a disease, which can be easily remarked. In this case we have to put the fish in a separate tank and feed it with lot of fresh living food.

Breeding freshwater fish in aquariums requests a minimum of knowledge about the anatomy and biology of the species you want to breed. The next few information, available for everyone, will allow you to keep healthy aquarium fish in the best conditions, will allow you to feed them right to guarantee their rising, facilitate their reproduction, with other words it will help you understand freshwater fish better.

The food must provide freshwater fish the necesary elements for biosynthesing proteins for thei body and the energy indispensable for their survival (this is the function of proteins, glucose and lipids). Feeding a freshwater fish means providing it a good develope, facilitate its reproduction and help it fight against freshwater fish diseases. The quality and quantity of food are 2 important terms; you have to avoid the supercharge and you also have to diversify the food.In the temperate zones of the globe, the reproduction of fish depends on the season, namely it depends on the temperature. There is a single season to spawn, in the time when the fish breeds. In tropical environment, where the temperature variations are less important, the breeding of fish takes place depending on other factors, mostly on rains. Aquarium fish are able to breed more times a year, sometimes at intervals shorter than a month.

You must learn to detect the symptoms of diseases and mostly to get use with the maintenance and hygiene standards, in order to prevent any disease. An exotic fish can be sick, but also a disease carrier without suffering the symptoms. The disease will activate in certain conditions and will spread to other aquarium fish.

Most of the times we first buy an aquarium and only then we think where we should place it. The disposal place of the aquarium must be carefully selected, because after you mount the aquarium, it is very hard to change its position. While moving it you can even break the aquarium. That’s why it has to be empty, with no fish and no plants and moved in another place. Choosing the place for an aquarium is very hard. For example, if we place a small aquarium close to a door or window, the temperature variations will be high regardless of the heater. Then the fish diseases may occur. If it is placed in the kitchen, or in places where you work with volatile substances - oil fumes – will produce the tuck the valve of the vibrator or may produce oil shell on the aquarium water surface.
Another element that we should consider in placing the aquarium is represented by the light. If we place the aquarium where it receives south light, this thing won’t allow the breeding of green and blue algae but the only plants that could grow are Cryptocoryne which need a low quantity of light. A placement near a window which receives north light will create an over flow of green and blue algae. Neither the west orientated windows give too much light, that’s why the recommended places are near windows that receive east light.
There are 2 ways for placing the aquarium in order to be able to use the solar light from windows:
- aquarium disposal on the opposite wall
- aquarium disposal on a wall perpendicular to the one with the window
In both cases the light is received by the front face of the aquarium, assuring a good illumination for both small and big plants. Placing the aquarium like that is in the benefit of fish too because they can receive good light and they will be more active and will show their real colors

The pH measure water`s acidity or alkalinity. 7 means neutrality; under this value this water is acid and, up from this, basic. An acid water doesn`t contain dangerous acids; in forest`s rivers it fills with organic materials and acids provided by the decomposed plants (humus); it can be recognized by it`s light yellow color. Generally, aquatic`s lift is possible only between 5 and 9. These extreme values may be obtained rarely in the aquarium, where the pH varies between 6 and 8, depending on water`s type. In aquarium`s science books is talked about an acid water when the pH varies between 6 and 6.8 and about a basic one between 7.2 and 8.
Between 6.8 and 7.2 it is consider a neutral water. These changing values of the pH are because of the biological alternations. The carbon dioxide produce by creatures when it`s night makes water to became more acid and the pH is decrease slowly. In time when it is absorbed by the plants the value is increasing again. A weak vary is considered normal but big difference show that there are problems. The pH is a good indicator of aquarium`s equilibrium, and it is a constantly measure indicator. With the help of a colored indicator we are able to compare the obtained colors on a calorimetric scale; there are electronic pH-meters too.

pH adjusting
Water doesn`t certainly have a likeable pH for the fishes. Furthermore, when an aquarium is functioning the pH can slowly but regularly increases or decrease. Some products can help pH adjusting but there are different ways which help us to do the same thing:
- if the pH is too high we can add a more acid water, limit water`s agitation, or filter the water with the help of the peat which will eliminate some acids.
- if the ph is too low we can add basic water, we care grow water`s agitation (which help the removing of carbon dioxide or we can filter the water with a calcareous material.

While the air contains 20% oxygen, the most oxygenate waters rarely contain 1% oxygen. The fish have some organs, branches, allowing them to extract the most oxygen dissolved in water. The oxygen is also used in plants respiration and other invisible creatures from the aquarium, such as bacteria. These convert the organic compost resulted from organisms (excrements, food, other); the chemical reactions for this conversions also require oxygen use.
The water oxygen results from dissolving of air oxygen, favored by water motion: wind, current, flow. The water is more oxygenate if it is tumultuous. The plants also produce oxygen by photosynthesis, but only while daylight. The maximum quantity of oxygen in water depends on the temperature; as the temperature increases the oxygen level decreases (at 25° C there is 18% less oxygen as at 15° C). The oxygen level is measured in mg/l and the dosage is quite delicate. The most oxygenate waters contain about 8-10 mg/l oxygen, and the most pauper ones 2 mg/l. In aquariums, the oxygen level is usually at maximum. The problems appear only if the general balance is not respected, (fish overpopulation and few plants) or when the materials don`t work (interruption of energy or oblivion).
The carbon dioxide results from the fish, plants and bacteria respiration. The motion of water, which increases the oxygen level, decreases the carbon dioxide level, which goes in the atmospheric air. In aquariums, you can rarely find important quantity of dioxide, which could affect the plants. In day time, he plants absorb the dioxide and use it for photosynthesis in order to produce oxygen, indispensable to aquatic life. A permanent equilibrium should be settled between oxygen, dioxide, fish and plants. This equilibrium changes during night when the plants stop providing oxygen. The carbon dioxide is one of the important factors which affect the pH.

An important water parameter for the aquatic life, influencing the quantity of oxygen but also lots of very important factors which contribute to developing life in aquariums. Otherwise the internal temperature of the mammals which is constant, the temperature of aquarium fish and other creatures varies depending on the aquarium water temperature. They can only survive at certain temperatures, some fish species being sensible to this water parameter more than others.
The tropical freshwater is characterized by lower temperature variations in comparison with the temperate water such as the ones in France; their amplitude is between 20 and 30 ° C. Local, the tropical forest shade decreases the temperature of the water, but the water temperature increases in the stagnant ones under the direct influence of the sun. An aquarium water temperature of 25° C is mostly recommended and variations of 1-2° C are insignificant. For short periods of time (less than 24 hours) aquarium fish can survive to higher variations, instead, for longer periods, their metabolism (the general performance of their body) risks to be highly perturbed, death can occur in shorter or longer periods of time. Also, in most cases, low temperatures favor disease developing.

This closed envitonment existing in an aquarium can help you understand some ecologic phenomenons and it represents a great start in this science which came into sight just a century ago. It doesn’t reflect only to the human being in its environment, but reflects all the mecanisms that regulate the relations between people and their environment. Even if lots of freshwater fish breeder, mostly beginners, remain izolated, it is verry profitable to make contact with aquarium clubs and associations. This way, the aquarium becomes a small world where we recognise the interrelations between ecologic factors at global level, relations that were able to explain the dependings between creatures. Also taking care of an aquarium, or better, mentaining the equilibrum in an aquarium, can be considered a task that a child should assume, being conscious of the responsability. Many parents buy a pet to their kid in order to develope its responsability sense, but only few pets are so suitable as aquarium fish. For example, a dog requests taking it outside and the child may be in danger without the supervision of parents, but the aquarium fish are completely harmless (at least the freshwater ones).
Without water there would be no life on our planet. But neither a too clean water is suitable for creatures developing. Life developing depends on the elements that water contains. The life and aquarium fish and plants breeding request some knowledge about water parameters, environment element mostly not known as life environment. In the aquarium the same phenomenons take place as in nature, of course at a lower level, that’s why the most important element’s cycles are present in aquariums too: carbon, nitrogen, oxigen… the quality of aquarium water being very influenced by the quantity of organic compound determined by the presence of aquarium creatures.

Aponogeton crispus
This aquarium plant is native from south-east Asia. It is a submerged plant having a round rhizome which can grow up to a 3 cm diameter. The leaves have varied dimensions between 15 and 16 cm, curly edges and they are colored in light green to ferruginous brown. This plant usually has a spherical shape. It only makes one white flower. The optimal temperature is 20-30° C. The light can be very strong but half-dark is not bad either, this fact influences the color of the leaves. The ground must be full of minerals and should be formed by sand, loam and boiled peat. When the plant stops growing, the rhizome must be replaced in a new aquarium with a temperature of 15° C. It only multiplies by seeds, which have an elliptic shape, 5-6 mm length and 2 mm diameter. The have 2 prolongations which in horizontal position get curved and stuck into the ground forming the roots. It`s better to plant the seeds in a smaller aquarium first, with a water level of maximum 30 cm.