Fish sleep at night and during the day
Fish sleep is significantly different from human sleep . The reason for this is the peculiarities of their habitat: fish cannot afford to disconnect from the surrounding reality - it is important to quickly react to approaching danger or prey.
Therefore, they never fall into a state of deep sleep - the animal’s brain works constantly. This occurs due to the alternating activity of its hemispheres, which allows the fish to remain conscious.
They do not necessarily sleep at night, it all depends on the species and the characteristics of its life activity: some fish are active during the daylight hours, others - during the dark.
Therefore, it is important to create appropriate conditions for them:
- provide a place to hide;
- choose the right neighbors so that their regimes coincide;
- Always turn off the lights at night.
In addition, fish, like people, do not like their peace of mind being disturbed.
Why you need to know your sleep schedule
Sleep is a natural physiological state of the body, during which the reaction to the outside world decreases and brain activity is reduced to a minimum.
Important! Make sure that the aquarium is not exposed to too much light, as it will irritate its inhabitants.
This is how people, mammals, birds, some insects and fish sleep. On average, a person spends a third of his life in a state of sleep. At this time, the heart rate decreases and breathing slows down, and muscles relax. Thus, we can say that at this time the body is inactive. Pisces have slightly different biological functions of the body, so they experience slightly different processes during sleep.
- During sleep, fish are not in an unconscious state; they partially continue to perceive and be aware of what surrounds them.
- During sleep, there are no significant changes in the brain activity of fish.
- Sleeping schedule is important for the inhabitants of the aquarium, as it allows them to adapt to the environment during the period of life.
Photos of what sleeping individuals look like
Sleeping fish are difficult to recognize because they do not close their eyes . This is due to the absence of eyelids, which they simply do not need - water already cleanses the surface of the eyes.
But this feature of the structure does not interfere with rest: at night it is quite dark, and during the day there is always a place where a small amount of light penetrates.
From the outside it looks like the fish are simply drifting in the water and barely noticeably shaking their fins and tails. But as soon as you make a sudden movement or turn on the light, activity in the aquarium will instantly resume.
In the photo you can see how the fish sleep:
Is there winter or summer hibernation?
Sometimes some fish breeds can fall into a state similar to hibernation - the same sleep, but longer (up to several months) and deeper.
At this time, all physical processes in their body slow down greatly, and the aquatic inhabitants themselves freeze in the water column or settle down at the bottom.
Hibernation is very important, because thanks to it, fish can endure heat, drought, dehydration and other unfavorable conditions in the summer.
For example, a species of fish was discovered in Africa that can form a mud cocoon around itself and hide in it for several months. The inhabitants of aquariums do not have such a need, but in the event of a threat to life, they are also able to fall asleep for a long time.
Hibernation is more typical for inhabitants of natural bodies of water . When cold weather sets in, fish hide in secluded places or go deeper. They then create a cocoon of mucus around themselves to protect them from germs and predators, after which they go into hibernation for the entire winter.
Catch fish swimming upside down?
If you notice a fish sleeping upside down, then this is definitely not normal behavior, whether sleeping or not.
Fish that swim on the surface or bottom of the tank, even when not sleeping, and who may also appear upside down, may be suffering from something called bladder disease.
For fish with certain types of anatomies, such as goldfish, this condition can lead to an imbalance in buoyancy, causing your fish's telltale sign to be less able to control their range of motion and alignment.
If you notice this behavior, it is important to immediately investigate the cause and immediately take any appropriate action as soon as you notice it.
Where do they do this?
The inhabitants of the aquarium sleep in different ways, but there is one common feature - their activity becomes minimal. Some fish simply “hang” in the water, others cling to leaves or branches of plants.
There are also those who make themselves more comfortable on their sides or abdomen, sinking to the bottom . There are also those who like to sleep with their belly up, frozen upside down and even buried in the sand.
This mainly depends on the presence of a swim bladder, that is, that organ that contains air and allows fish to rise to the surface of the water, stay in its thickness, or sink to the bottom. This way, the inhabitants of the aquarium have the opportunity to remain at a certain depth even during sleep.
However, not all fish have a swim bladder , which means that they need to constantly be in motion to avoid lying on the bottom. It would seem like a good option, but the gills of such individuals are designed in such a way that they can only receive oxygen by moving.
Therefore, fish are forced to move even in their sleep or find places with a bottom current that will self-wash their gills. Among aquarium fish there are few of these - loaches, ancistrus and catfish.
When setting up an aquarium, you need to take care of places for sleeping: plant algae, arrange figurines, put driftwood and stones.
“Hanging” of a fish in a strange position can be associated not only with sleep, but also with illness . Therefore, when such behavior is observed in a pet for the first time, it is better to knock on the glass near it and observe the reaction. If he returns to his normal activities, everything is fine.
Angelfish: breeding at home
Sex determination in angelfish and pair formation
Sexual dimorphism in angelfish is not pronounced, i.e. males and females are almost the same in appearance. It is impossible to determine gender before the onset of puberty, and even then it is quite difficult. Aquarists joke about this: “If it swam, it means a male, if it swam, it means a female.” However, in adult angelfish it is possible to determine the sex in most cases, although this can usually only be done by those who know the anatomy of fish well. Let's try to figure out what characteristics determine the gender of fish of this genus:
- In mature males, there is a fatty hump on the forehead;
- Males have a more convex pectoral carina;
- If you look at the fish from the front, then the lower part of its body resembles a wedge, and in the male this wedge is sharp, and in the female it is blunt;
- The diagnostic sign is the genital papilla (in females it is called the ovipositor) - a growth with an opening located between the anus and the anal fin, through which reproductive products come out. In females it is larger and thicker, while in males it is correspondingly thinner, sharper and directed backwards. These differences are especially clearly visible during spawning, as well as before and immediately after it;
- The distance from the genital papilla to the anal fin is much shorter in males than in females. In fact, in males the fin keel grows directly from the genital papilla, and since in striped angelfish the papilla is usually located at the base of the central stripe, we can say that in males the anal fin starts from the base of the central stripe, and in females - behind it;
Male angelfish differ from females in having a more elongated, long dorsal fin. In its rear part there are dark transverse stripes interspersed with gaps. The number of these stripes in females is no more than 6, and in males there are no less than 7. However, sometimes it is impossible to reliably determine the gender of fish based on these characteristics, especially in artificially bred forms with marbled, golden, albino coloring. In such cases, they try to determine the sex of the fish by their behavior when they form pairs and begin spawning in a common aquarium. But this does not always work: in some cases, in the absence of males, females play their role in mating games and spawning, and same-sex couples even lay eggs (which, naturally, remain unfertilized).
Here we can advise the following: if you want to purchase an adult breeder fish, choose an individual with characteristic features and behavior, or a fish that has already given birth to offspring. It’s even better if it’s an established couple right away. If you are going to raise breeders yourself, purchase 8-10 fry with wide and long fins, among them there will definitely be individuals of both sexes, and in the future they will split into pairs themselves, and you can decide which of them to use for further breeding.
Angelfish prefer to form pairs on their own, choosing a partner from several individuals of the opposite sex. But the aquarist may well choose a pair of an existing young specimen. When a male and female angelfish of similar age and size find themselves alone in an aquarium, as a rule, they begin to “build love.” It is not recommended to separate ready-made couples and select other partners - this is extremely stressful for fish, and they do not always form new unions. It is easy to identify a formed pair: the fish stay together, swim in single file, and the male begins to drive the female into the corners of the aquarium.
Raising spawners and preparing for spawning
Fish that are planned for further breeding must be kept in optimal conditions. For angelfish, the water temperature is of particular importance, which should not be lower than 27°C. The second most important factor is the quality of food; future producers must eat live food (bloodworms, tubifex, daphnia, etc.) or frozen food throughout their lives. Angelfish raised exclusively on dry food are usually smaller in size, their coloration is paler, and they are often incapable of reproduction.
In good conditions, angelfish can spawn every two weeks, provided the eggs are removed immediately.
Before spawning, males and females must be kept together, since the preparation of males for spawning and the maturation of their reproductive products takes place only in the presence of females.
Spawning is stimulated by increasing the water temperature by 2°C, frequent changes (3-4 times a week, 10%), while it is better to add distilled or boiled water to reduce its hardness in the aquarium. The aquarium should contain large-leaved plants; you can also place a piece of plastic or ceramic tile there on which the angelfish can spawn. Typically, fish of this genus are not placed in a separate spawning tank, allowing them to spawn in a general aquarium.
A pair ready for reproduction can be recognized by the female’s rounded abdomen and changed behavior - future parents begin to zealously guard their territory and clean the surface on which they will spawn.
Spawning
Incubator equipment and egg development
Angelfish, like other cichlids, care for their offspring, but their parental instinct is not so strong, and this care usually lasts only 2-3 days. Having spawned, the spawners begin to protect the eggs from other fish in the aquarium, fan the eggs with their pectoral and dorsal fins, pick up the eggs that have fallen from the substrate and eat the white ones. In some cases, they take care of their offspring until they begin to feed on their own. I must say that this care is very useful for the fry. But, unfortunately, such exemplary behavior is rather an exception to the rule, and usually producers simply eat the eggs a few hours after spawning or after dark. Therefore, if you do not want to risk finding out how caring parents your angelfish are, it is better to transfer the eggs to a separate aquarium 2-3 hours after spawning.
An incubator for caviar is prepared as follows: a small aquarium with a capacity of 5–10 liters is half filled with water from the aquarium where the breeders are kept. The second half is added with distilled water. A heater set to a temperature of 30°C and an air sprayer are placed in the incubator, and after an hour, the substrate with eggs is lowered into it so that the eggs are washed by the current from the sprayer, but air bubbles do not fall on it.
To prevent fungal infection of eggs, add methylene blue to the water until it turns intensely blue or Sera mycopur at the rate of 1 drop per liter. It is useful to place small plants in the incubator, such as duckweed or riccia, they will act as a biofilter, preventing the level of nitrogen compounds in the aquarium from jumping when the fry begin to grow quickly. In addition, ciliates and rotifers will multiply in the thickets, which will then become food for the fry. Lighting should be around the clock. Even if there are no plants in the incubator, you should leave the night light on at night.
The next day, the whitened eggs are removed.
Development of fry and care for them
After two days, the shells of the eggs rupture and turn into sticky ropes on which the larvae hang, moving with the help of a tail similar to a flagellum. On about the fourth day, the larvae can distinguish their heads and yolk sacs, from the reserves of which they feed. The larva constantly moves, trying to free itself from the cord that attaches it.
After 7–12 days, the cords break off and the fry begin to swim. By this time, the yolk sac is almost empty, and it is time to start feeding the fry. It is impossible to fully feed them with egg yolk and dry food, so live food is prepared in advance: ciliates and daphnia are bred, and on the 5th day after spawning, they begin to incubate artemia. The fry are fed 5–6 times a day. Now you need to place a small filter in the aquarium, and to prevent the fry from being drawn in, the lower part of it is covered, for example, with a nylon stocking. If there are a lot of fry, some will need to be removed from the aquarium; their density should now be no more than two per liter of water, otherwise the level of ammonia and nitrites may rise sharply. Water changes are carried out once a day by a third, before feeding, after removing the remaining food from the bottom with a siphon.
In about a month or a month and a half, the fry will acquire the shape characteristic of an angelfish, after which they will again need to be seated in a container at the rate of 4–5 liters of water per fry. At this age, they are fed with chopped tubifex, small bloodworms, they can begin gradually accustoming them to live food, and after a short time they can be placed in a common “adult” aquarium.
As you can see, breeding angelfish is a troublesome, painstaking, but very interesting task. Even if you don’t get everything right the first time, you will have a chance to try again, because a couple of healthy fish in good conditions spawn often. And sooner or later, the persistent aquarist will be able to boast of a flock of bright young angelfish, which he raised from eggs. Now all that remains is to find them a new home, thereby increasing the number of lovers of these amazing fish.
Read about keeping angelfish in the following article, and now a short video about the spawning of these fish:
Impact on compatibility of different species
After studying the behavior of aquarium fish, scientists divided them into 2 categories:
- crepuscular - those who see well in the dark, so they hunt at night and rest during the day;
- light-loving - those who are active during the day.
Representatives of the first category are predominantly predators. When selecting fish for an aquarium, it is important to know what type they belong to, because representatives of groups should not be allowed to be close together.
This is due to:
- incompatibility of characters - predators will simply start eating ornamental fish;
- the fact that twilight fish are uncomfortable in bright lighting, which is necessary for light-loving fish;
- a discrepancy between sleep and rest patterns, which will provoke illness - the inhabitants of the aquarium will constantly interfere with each other.
An aquarium with dusky fish needs a large amount of thick algae where they can hide and rest.
Interesting Facts
Some interesting facts about fish, fish and sleep:
Parrotfish have “night pajamas” - before going to bed, they create a cocoon of mucus around themselves.
It is believed that such a bubble is designed to protect them from predators: it masks the smell, and in the event of an attack, it gives the victim time to wake up and react.- Sharks do not have an air bladder, so they adapt differently to be able to sleep.
This is how the Katran shark sleeps while moving - its spinal cord is responsible for movement. Other sharks constantly open and close their mouths when resting, allowing water to move around their gills. - If the fish does not manage to sleep, then it tries to make up for rest at the first opportunity.
- When fish are stressed, they may suffer from insomnia.
