Dogs, people and fish breathe for the same reason. Everyone needs oxygen. Oxygen is a gas that bodies use to produce energy.
Living beings experience two feelings of hunger - gastric and oxygen. Unlike the breaks between meals, the breaks between breaths are much shorter. People take about 12 breaths per minute.
It may seem like they only breathe oxygen, but there are many other gases in the air. When we inhale, the lungs fill with these gases. The lungs separate oxygen from the air and release other gases that the body does not use.
Everyone exhales carbon dioxide, which their bodies produce when they produce energy. Just as the body sweats when we exercise, the body also releases carbon dioxide when we breathe.
Fish also need oxygen to move their bodies, but the oxygen they use is already in the water. Their bodies are not like humans. People and dogs have lungs, fish have gills.
Mathematicians explain how shrimp swim
Antarctic krill swim using wave-like movements of their legs (photo Uwe Kils/Wikipedia Commons).
Some crustaceans, such as shrimp and lobsters, swim using the rhythmic movements of four or five pairs of pleopod limbs, similar to small oars.
Each leg first pushes the water back with force, and then bends to reduce resistance and moves to its original position. The frequency of such movements can reach ten shocks per second. In this case, the limbs do not row simultaneously, but in strict sequence. First, the pair of legs located closer to the tail pushes, then, with a delay of a quarter cycle, the next one, and so on. From the outside it resembles waves going from the tail to the head.
A group of American scientists, consisting of four mathematicians and one biologist, decided to figure out why, during natural selection, crustaceans chose such a complex swimming style. Using a computer model that takes into account the dynamics of fluid flows, the researchers compared three rowing methods: synchronized movement of all legs at the same time, wave-like movements from the tail to the head and in the opposite direction.
“When I first started thinking about this type of swimming, I thought that a head-to-tail movement would provide a greater mechanical advantage, but simulations showed that this was not the case,” says co-author Timothy Lewis of the University of California, Davis. .
Calculations have shown that the movements of shrimp and lobsters are 30% more effective than synchronized strokes and more than three times more effective than movements directed from head to tail.
Having discovered that the crustaceans chose the most rational method of swimming, scientists decided to carefully study the neural circuits that control this process.
“Each paddle is controlled by a pair of nerve cells that take turns inhibiting each other,” explains biologist Brian Mulloney. — One neuron controls the push, the other controls the reverse move. The result is a rhythmic pulse similar to a metronome.”
In turn, each pair of such metronomes is connected in a certain asymmetric way to the neurons of the next “oar”. Mathematical analysis has shown that such asynchronous communication is ideal to provide the quarter cycle delay required for the most efficient rowing.
Thus, using mathematical methods, scientists have demonstrated how, through natural selection at the level of neural circuits, organisms acquire complex behavior that allows them to use energy most efficiently.
More details about the results of the work can be found in the article published in the PNAS publication.
Kinds
These herbivorous cichlids feed on algal fouling, stripping it from stones. They have a mouth structure that is convenient for such a process. At a younger age, fish eat zooplankton, but later they simply need to eat plants. If you give them live food too often, they will quickly become obese and lose their ability to reproduce. All Malawian cichlids are divided into 2 large groups: “mbuna” and “utaka”. Mbuna cichlids, which means “rock attackers,” are distinguished primarily by their diet, which includes plant foods. The main representatives of mbuna fish are labidochromis, melanochromis, and pseudotropheus. The color of the fish is very bright, they reach up to 15 cm in size.
The “utaka” group includes cyrtocara, aulonocara, and haplochromis. On the contrary, fish eat live food and can eat their relatives. They are distinguished by their larger sizes, reaching up to 20 cm; the color of their females is much more modest.
Some of the most beautiful Malawian cichlids are considered to be the blue dolphin, various types of aulonocara, yellow and cornflower blue labidochromis.
Well posed
What are the diseases of Malawian cichlids?
All living things are susceptible to pathogens or other parasites. Our cichlids are no exception. If you see that the fish is swimming on its side or upside down, this may indicate inflammation of the swim bladder. This disease is caused by careless handling during transportation, fights between males, and various infections. Any fish that looks suspicious or is already sick should be quarantined. Here you need to keep all the newly purchased copies for some time. We list the common diseases of cichlids:
- ichthyophthyriosis;
- Malawi disease;
- argulosis;
- hexamitosis;
- lernea;
- oodiniosis;
- fin rot;
- bulging eyes;
- various intestinal parasites.
Aquarium three hundred
The text below does not carry any semantic meaning. You can just look at the pictures.
I am writing here because today is January 3rd and my liver is aching. I can't drink anymore. There is no work. Nothing to do.
In general, I want to share my new hobby.
At the end of September, a childhood dream came true - I bought an aquarium (a little later I also bought a cube, but more about that next time).
The path of this dream was long and thorny. First the parents, then the first wife, then the second. they were all against the aquarium. But three months ago I quit smoking, and in order to somehow take my mind off the bad habit, I silently went and bought a 300-liter jar. My wife fell silent for a week. And this was very useful, because... I spent this week reading articles and watching videos on launching and decorating an aquarium.
As a result, I bought a substrate, primer, driftwood and an external filter.
There were no issues with the choice of design. Soberly assessing my knowledge of aquariums, which is close to zero, I came to the conclusion that it’s not worth even thinking about any kind of scape, but that it’s worth trying to recreate the semblance of an ordinary river bottom (as I see it). Moreover, initially, it was planned to launch fish from local reservoirs: rudd, gudgeon, and topsmelting fish.
All of the above fish were quarantined in their home pond for six months.
Further, the process of creating the underwater world was suspended, because... the question became about plants. Or rather, where to get them. A quick survey of friends did not reveal any aquarists. But I simply didn’t know about the existence of such a place as “the bird.” But the well-known free classifieds board came to the rescue. This is how crypts, echoes and nymphs were acquired.
The aquarium was successfully launched in early October.
Over the next week, the previously designated fish were introduced.
There are no photos of rudd, everyone already knows them. And they sat in the bank for a couple of days, because... were caught in the act of eating aqua grass, as a result of which they were immediately deported back to the courtyard pond.
I really liked the minnows; they didn’t spoil the grass, but they also had their drawbacks. They were persistent speed limit violators. As a result, the manado flew throughout the aquarium. And all attempts to plant something ground cover ended with the same plants floating near the surface.
Aquarium 30 liters: description, care, maintenance, photo, video.
When purchasing an aquarium, think about what kind of fish you want to keep. If there is not enough free space in the room, a 30-liter aquarium is optimal. The volume allows you to accommodate a variety of aquarium inhabitants. For beginners this is the best option.
What lighting can be considered optimal?
A lamp for a 30 liter aquarium must have a reliable mount and create an optimal light flux. For this, incandescent lamps (ordinary household electric lamps), fluorescent or LED lamps can be used.
The power of incandescent lamps is determined at the rate of 1.2-1.5 watts per liter of volume. This lighting option is simple, but has a number of disadvantages: its luminous flux is clearly directed to one point, the water around this place gets very hot, and energy consumption is unreasonably high. The water in such an aquarium may begin to bloom, the walls become covered with a yellow (if there is a lack of light) or green (if there is an excess) coating. In aquariums equipped with electric lamps, blue-green algae and “blackbeard” are a frequent guest.
It is advantageous to equip an aquarium with a size of 30 liters with fluorescent lighting options (15-20 W will be sufficient power). Lamps can be daylight or have a certain yellowness. Their operating mechanism provides good light output, efficiency and the absence of a heating effect. The disadvantage is the mercury vapor included in the device. In the event of the smallest crack or split, they will enter the air of the room and create certain problems for human health.
The optimal and modern option for nanoaquariums is LED lamps. They are certainly more expensive, but they are economical, safe and effective.
In addition to the options described, today designers use low-power lamps that have colored shades. Thanks to them, fish scales shimmer, the greenery of plants becomes expressive, and corals and other design elements acquire a mysterious appearance.
For greater effect, place them on the bottom, along the line of intersection of the edges, behind the back wall.
Vegetation placement
Plants are not only a decoration for the aquarium, but also an integral part of the microflora of the underwater world. They allow you to saturate the water with oxygen and also serve as shelter for many species of fish. For beginners, it is better to choose unpretentious plant species. In a relatively small house, not exceeding 30 liters, you can “settle” the following types of greenery: Heteranthera; Congo fern; Javanese, Key or Weeping moss; Pogostemon Helfera; Hornwort; Anubias Barthera dwarf; Hemianthus dwarf Cuban. The amount of greenery is planted in accordance with the volume of the aquarium; the plants should not be too dense. Otherwise, guppies, catfish or barbs will feel uncomfortable.
Filter
Constant water purification is an undoubted benefit. Modern filters purify water not from everything, but from pathogenic bacteria, dirt, rot from plants and food. Fish quickly get used to the fact that water flows are constantly moving, and do not experience the same stress as from constantly dragging a filter, which we can encounter in a ten-liter aquarium and in a twenty-liter aquarium. There are a great variety of filter models, and it is not difficult to choose the best option.
The filter operates under the pressure of the water mass. Therefore, it makes no difference what size the filter is: the main thing is that it supports the required power. For small aquarium devices, this power is optimal from 25 W to 40 W, although a device that is too powerful may work poorly and drive too strong flows of water.
The safety rules for the filter, regardless of its power, are the same:
- The filter should not be left turned off in the aquarium for a long time. If this does happen, or your lights have been turned off for a long time, you need to remove the filter from the aquarium and clean it properly.
- Do not put your hands into the aquarium while the filter is running. However, this applies to any electrical equipment that is directly related to the aquarium. In this way, you can get a discharge by carelessly jerking against the device, not particularly strong, but quite noticeable.
- The filter must not be allowed to remain exposed to air: it must be completely immersed in water, otherwise this will affect its performance.
- A filter that has been removed from the aquarium for a long time cannot be immediately put back: you need to first wash it or completely replace the filtration material in it.
- A newly purchased filter must be thoroughly washed so that the factory smell and accidentally introduced bacteria do not harm the fish.
You need to place the filter no closer than three to four centimeters from the bottom, and make sure that this gap remains constant, since water from the aquarium tends to evaporate, especially under intense lighting.
But at the same time, you need to follow the golden mean, and not leave the working parts of the filter in the air: the device must be completely covered with water. A non-functional or faulty filter must be immediately removed from the aquarium.
Compressor
A compressor in a thirty-liter aquarium is absolutely necessary. Saturating the water with additional oxygen will be very important for large and small inhabitants of the aquarium, so you need to take care of the right source. The compressor, in fact, is not mounted inside the aquarium, but mainly on the side or rear wall of the aquarium from the outside. A hose comes off the compressor, which we actually lower into the water. There is a sprayer on the hose, which supplies oxygen to the water. The hose also contains a check valve: it prevents water from entering the hose and does not allow it to pass into the compressor. The most important condition that must be observed is to ensure that the hose with the sprayer does not scratch the bottom. The sprayer becomes clogged with microparticles of soil, and because of this it stops working normally. The location of the hose itself, of course, depends on where you mount the compressor. Usually the compressor is mounted on the back wall of the aquarium, or on the side wall - the one that is located further from the passage near the aquarium. Thus, the hose ends up inside the aquarium from the side or behind, and is successfully masked both from the view from the outside and from the inhabitants by any plants or decorations.
The power of the compressor in an aquarium depends on its displacement. According to the common formula, for every liter of water in an aquarium, a liter of air is required per hour. Thus, for a thirty-liter can, we need a compressor capable of maintaining a power of 30 l/hour. An excess of oxygen will affect the inhabitants of the aquarium no better than a lack of it - do not forget that if you have greenery growing in abundance in your aquarium, then oxygen is produced one way or another: in this underwater plants are no different from any others.
So, we installed the compressor in a convenient place, now we create a supply of oxygen to the water:
- We attach a sprayer to one side of the hose and lower it into the water.
- We put a check valve on the second side of the hose: fasten it as best as possible to avoid even accidental water getting into the electrical appliance.
- We connect the end of the hose with the valve to the compressor, and turn on our design. If everything is in order, you will see characteristic bubbles running through the water.
For many years, one of the disadvantages of compressors was their annoying buzzing. Indeed, even a small device that distills oxygen constantly vibrates and buzzes. Therefore, many aquarists, especially those who installed an aquarium near their bed, turn off the compressor at night, which is not particularly beneficial for the inhabitants of the jar.
However, in recent years, a large selection of silent compressors has appeared, and the noise problem is gradually ceasing to exist. Of course, a lot still depends on the power, and a compressor operating on a huge thousand-liter aquarium cannot be absolutely silent, but in our case, if we are going to buy a 30-liter aquarium, the compressor will most likely be quiet.
It is best to check the operation of the compressor without first planting plants or starting fish, observe its performance, check for possible problems and, of course, the strength of the check valve. It can be installed in the aquarium as the very first device, and while all other nuances are being prepared, observe whether everything is in order with the oxygen supply.
In general, there is no need to rush to start an aquarium. This process is calm, measured and peaceful, so the main thing that can be advised to a novice aquarist is to be patient and act carefully and step by step so that plants, fish, snails and any other inhabitants of the aquarium take root. After reviewing the equipment, we will return to the issue of the launch algorithm.
Aquarium inhabitants
Now it’s time to decide which fish should live in a 30-liter aquarium. This issue should be taken very seriously, because relocation in an aquarium can lead to disastrous consequences. It is advisable to start with fewer fish at first to avoid unnecessary troubles. In an aquarium of this size, it is worth choosing several small schooling fish or a couple of medium-sized ones, for example, honey gouramis or macropods, apistograms or pelvicachromis. In addition to fish, you can place various shrimp, crabs and shellfish. Only small fish should live in a 30-liter aquarium, since large fish will be uncomfortable living in such modest volumes.
Accommodation options
To populate the aquarium, you can choose one of the proposed options: • 3 cockerels, • from 9 to 12 cardinals, • about 15 neons, • 15 Norman blue-eyes, • about 20 guppies, • 20 Endler guppy fish, • a little more than 30 microrasbor fish Now let's look Brief information about each type of fish: Bettas Bettas are a very common type of fish. Males have beautiful fan-shaped fins. Females do not have them, but they have bright colors.
The required water temperature is 26 degrees. The size of an adult is 5–6 cm. Cardinal A very interesting and active fish. She likes to have an abundance of plants. Unpretentious to food. The required water temperature is 18-21 degrees. The size of an adult is 2 cm. Neons Quite interesting fish that live in schools. Taking care of them is completely easy. Neons, like cardinals, prefer to have a lot of plants in the aquarium. They need soft water. The required water temperature is 22-25 degrees. The size of an adult is 4 cm. Norman's Blue Eye: A beautiful schooling fish that has bright neon eyes, which gives the aquarium a special look. The fish is mobile and active. The required water temperature is 20-25 degrees. The size of an adult is 3-4 cm Guppy A completely unpretentious species of fish. Males have a brightly colored body and a beautiful tail, females are gray and inconspicuous. They have a high degree of fertility: after only a month of acquiring a female, 20 fry can be seen. They are not picky about water temperature. The size of an adult individual - male - 3-4 cm, female - 6 cm. Endler's guppies Endler's guppies are a type of guppies that have not yet been influenced by selection. These fish are slightly smaller than simple guppies: males grow up to 2-3 cm. Microrasbora A very small fish that is perfect for very small aquariums. This type of fish is unpretentious to water. The required water temperature is 22-28 degrees. The adult size is 2 cm.
Decorative elements
To create an original design for a 30-liter aquarium, you need to take care of decorative elements. Thanks to decorations, you can decorate an artificial pond in a different style. For these purposes, the following elements are used: various “wallpapers” for the back wall of the aquarium; driftwood; shells; locks; ship models and more. After recreating the atmosphere of the underwater kingdom, it’s time to think about what kind of fish to put in an artificial pond and how many snails should be in the aquarium.
Heater and thermometer
So, when we already know everything about filters and compressors, it’s time to talk about temperature - in our case, this is the temperature of the water in the aquarium.
Your task in regulating the temperature comes down to increasing it: you cannot cool the water by any means. Perhaps, if there is room in the aquarium, you can very carefully add a little cooler water. However, we will now talk about heaters. In the middle zone, winter is sometimes very aggressive, and even with normal heating in the house, sometimes the room temperature, at best, is +20 degrees Celsius. The aquatic environment tends to maintain the temperature of the environment surrounding the aquarium, so we just need to get a heater and, of course, a thermometer.
So, let's choose a heater. Inexperienced aquarists imagine a heater as a kind of boiler that they stick into an aquarium and wait for the water to warm up to the desired temperature. In reality, the process is somewhat more complicated.
There are two types of aquarium heaters that differ in their design: mechanical and electronic. A mechanical heater is usually less accurate and will not be suitable if you have pets that are particularly sensitive to temperature changes. It usually has an error of two to three degrees. Its only significant advantage is its low cost. An electronic heater is much more precise, so it can be used to regulate the temperature as accurately as possible.
Such heaters, the classic flask shape, are the most common. However, there is another version of the bottom heater, which runs along the bottom under the ground in the form of a cable, which gives a certain head start in aesthetics, but at the same time, such a heater cannot be quickly removed or positioned without damaging the exposure and without digging in the ground.
In addition, there is also the option of heating mats, but replacing them is even more difficult - you have to completely raise the aquarium, and they waste most of the heat generated. True, there is no particular danger of overheating.
Most modern heaters have a thermostat, with which you can set the temperature that needs to be maintained. Devices without adjustment heat water and, in fact, follow the principle of a boiler, constantly supplying heat. Therefore, if you decide to just buy a heater, then you need to calculate the power of the device based on the displacement of the can. When purchasing, it is best to consult with the seller or an experienced fish owner so as not to miscalculate the parameters you need. It is worth very, very carefully to ensure that the heater is working properly.
Therefore, be sure to attach a thermometer. Temperature meters are also not the same: there are versions of external and internal thermometers. The outer ones are glued to the front or side wall of the can with Velcro, and determine the temperature through the glass, which, in principle, is not particularly accurate. Internal options cling to a suction cup inside the aquarium, and the only thing that can threaten such a thermometer is being thrown into the ground by a particularly active inhabitant of the aquarium.
As you know, there are only two possible ways for a heater to malfunction: the heater does not turn on and does not turn off. In the first case, everything is not so scary - the fish will not have much fun, but will survive a temporary drop in temperature. In the second case, when the heater does not turn off, we have every chance of getting a rich fish soup from exotic fish if you were not near the aquarium at the time the device broke down. Therefore, you should take a very responsible approach to choosing a heater so as not to cause irreparable harm to the population of the aquarium.
The temperature for spawning fish should in some cases be slightly higher than the temperature for aquariums with adult fish, but in any case the optimal temperature ranges from +25 to +27 degrees Celsius: this is the standard at which almost all types of freshwater ornamental fish can live relatively normally fish, frogs and shrimp. Each pet, of course, has its own specific maintenance rules, and when choosing an aquarium population, you should carefully read them.
So, we install the heater we have chosen in the aquarium. It is best to also check before introducing fish, so that if the optimal temperature cannot be created, try other equipment options. If everything goes well, then you can start planning the lighting.
An aquarium that has not been used.
Pinned: I will share Helena and cherries in St. Petersburg, of course, free of charge, that is, for nothing, in short, the one who took it doesn’t owe me anything :)))
We lived outside the city for almost 8 months, and there were only two water changes in our freshwater tank (which was a ton of sea water).
So everything grew during this time, the moss, by the way, was just a twig that fell into the jar along with the cherries. The best filter feeders, they have grown up, although due to the current they are all “in a fur coat” of beards or flip-flops. at least one Gabonese out of three is alive, they are cowardly, so they filter in the corners as usual.
But they look happy and well-fed and sit on the central snag.
An incredible number of cherries have grown, but their quality leaves much to be desired, we will add new blood.
Last night I saw a fry of Corydoras Pygmies, they seem normal, but they hide during the day.
It sucks for rasboram espei, there are some sick ones, at least a couple, while I’m thinking about how to catch them.
Numbered catfish sometimes come out, but in such thickets they are not easy to see
Helenas multiplied, there were 5 of them, now it’s difficult to say how many.
All this time, CO2 was supplied to the aquas and the light worked on a timer.
During replacements, only the drakh was removed from the drain and that’s it, by the way, you can see how much riccia had grown on it.
Features of Lake Malawi
The territory of Lake Malawi is the only park in this state; it contains over 500 species of cichlids, most of which are endemic. The history of the discovery of Lake Malawi is associated with the name of the Scottish explorer of the African continent, David Livingstone, who discovered this freshwater lake in 1859. Initially, the reservoir was called “Nyasa,” but after the state gained independence, the lake was given the name “Malawi,” which translated means “shining light above the lake.” The lake lies along the borders of three countries: Tanzania, Mozambique and Malawi. It is part of one of the largest lakes on the planet; several of its islands are declared nature reserves.
Breeding rules
Malawian cichlids are not monogamous; a male is able to spawn with several females at the same time. Although there are individuals who choose a mate for life. Females lay eggs on a flat stone or in a pre-prepared nest. They hatch eggs and fry in their mouths. It is easy to determine whether fish are ready to reproduce in an aquarium - the anal fin of the male becomes sharp, and in the female it becomes cone-shaped.
The amount of eggs varies between species, depending on age and water conditions. Usually the larvae of the fry appear after 2-4 days. Producers care for the offspring, sometimes the female and the male fight for primacy over the offspring, organizing disputes and fights. In this case, the male or female is removed from the spawning tank. Also, during the spawning period in a general aquarium, hybridization of species is possible. Hybrid offspring do not have such bright colors.
Compatibility
There are many compatibility tables for aquarium fish. But you need to understand that the behavior of these beautiful creatures is influenced by many factors - the size of the tank, its design, the type of food, even the water temperature. Cichlids can get along with other fish, especially if they are not too different from them in size. But the “Malawians” prefer to control the territory, and fights between the inhabitants of your aquarium are almost inevitable. How can you reduce aggression? It is best to introduce all your cichlids into a new aquarium at once. If you do this in stages, then the old-timers can attack the newbies. Also in this matter, various shelters play an important role - driftwood, stones, shells. Each inhabitant will find shelter if desired and wait out the dangerous period.
Special among the special
The same shrimp or mantis crayfish is distinguished by complete fearlessness and frantic temperament at 10 centimeters in length. Not only does it behave as it wants, attacking everything around, hitting with its claws at a speed of about 80 km/h and with a force 2.5 thousand times greater than the weight of the mollusk itself, it also creates a shock wave of high temperature. Simply, it blows up those who get in its way.
Mantis shrimp are able to raise offspring in pairs or separate children and go their separate ways.
They are incredibly beautiful - they have a bright, multi-colored, sometimes luminous color.
Very dangerous. Nicknamed “finger blasters” and “killer shrimp.” To get to know them and watch how shrimp swim, it is better not to go underwater - it is much safer to appreciate this spectacle when watching a video.
Behavioral characteristics of the family Cichlidae
The behavior of these representatives of the underwater fauna is peculiar and attractive. Sociable and active by nature, cichlids are in constant motion, using the entire space of the aquarium.
Their activity increases in proportion to the increase in hunger. In pursuit of a portion of food, they organize real races and can instantly absorb everything that is offered to them, although such greed does not bring them any benefit.
Certain types of fish have highly developed hunting skills:
- livinqstonii, buried in the sand, pretends to be inanimate, thereby luring prey;
- compresessips, having a narrow and strongly flattened body, is hardly noticeable to other inhabitants of the reservoir, which allows it to approach prey unnoticed;
- copadichromis, having a tube-shaped mouth, is able to easily suck in plankton like a vacuum pump.
The intelligence of cichlids is attractive to aquarists. They are able to recognize their owner and demonstrate unique social behavior.
Thus, almost all varieties of this family have developed parental care for their offspring. Cichlid aquarium fish carefully guard their clutches and care for the larvae and fry. Specifically, the Malawian species of fish hatch eggs in their mouths, and the hatched fry find refuge in the throat sac of their parents in a moment of danger. Therefore, with a relatively small number of eggs in these fish, their survival rate is quite high.
