Water fleas in the aquarium
Content
Fans of solving skanvordov know that water fleas are called daphnia. These small crustaceans look very similar to blood-sucking parasites and make sharp original shocks in the water. However, on this similarity of water creatures with true fleas is ending. Daphnia do not drink blood, do not parasitize animals, fish, and most often themselves are food for waterfowl.
How do water fleas look and where do they live?
Daphnia belong to the genus of plankton crustaceans. Branched antennae are located on the head, which is why taxonomists rank them as a super-branch branched. They live everywhere, including Antarctica. You can meet their populations in any body of water, be it a puddle, a pond, a lake, or a river. The cold season water flea spends in the bottom layer. With the onset of heat is activated and under favorable conditions begins to multiply rapidly.
There are more than 150 species of Daphnia, which may have different color, body length. In the CIS, common species such as galeata, cristate, pullex, magna. Daphnia sizes vary in the range of 0.5-6 mm. The body is covered with a transparent shell, fastened on the back. Antenna antennae covered with bristles help the water flea to move and make vertical movements in the water column.
In addition to the antennas on the head there is one mobile eye, consisting of several small ocelli, cranberry outgrowth - rostrum. Due to the transparency of the body, you can use a microscope or a photo to examine in detail the internal structure. Daphnia's heart is located on the dorsal part, the kidneys in the upper part of the calf,and the brain is located near the esophagus.
Interesting!
The frequency of heartbeats in Daphnia Magna reaches 180 beats per second. Weak heartbeats indicate the disease state of the crustacean.
Water fleas in the photo, even if they belong to the same species, can vary in color. The color of daphnia depends on how much water is saturated with oxygen. With its excess, they are light yellowish or gray in color. If there is a shortage of oxygen in the pond, the body becomes dark brown.
What eat water fleas
In their natural environment, crustaceans feed on the simplest organisms: ciliates, bacteria, fungal spores, and free-floating algae. In summer, they can be found in the flowering water, replete with phytoplankton. In winter, detritus is a power source for water fleas.
With the help of the legs, crustaceans make rhythmic movements and create water flow. The bristles located on the chest legs filter the food. Then it enters the groove, and then redirected to the esophagus. Due to their dietary habits, daphnia culture is often placed in an aquarium to purify algae water.
Interesting!
During the day, one individual is able to filter from 1 to 10 ml of feed in water and consume the amount of food that is 6 times higher than its own weight.
Breeding water fleas
In the presence of an egg food base, females develop without male intervention. Embryos develop in a special chamber located under the sink. You can examine them in the body of the female even without a magnifying glass. The number of juveniles varies from 5 to 10. For all her life, the female is able to give life to 100 crustaceans. During the period in the chamber, the embryos moult.
Interesting!
The generation of females during partherogenesis always has the same sex. In summertime, young individuals of the female sex flood the reservoirs, and in the autumn period, males develop predominantly.
It takes 3-4 days for a newborn female to be able to replenish the reservoir with its offspring, and given that only females appear in the hot period, the population is growing rapidly.
The process of bisexual reproduction is possible with a decrease in temperature and an insufficient amount of food. Embryos are in the chamber and protected by a dense chitinous cover.During the molt, the female drops the capsule with the eggs, and she either sinks to the bottom or swims in the upper layer of water. The dense shell maintains the viability of embryos during freezing, high temperatures, in poisonous solutions.
The benefits and harm of water fleas
Contrary to the erroneous opinion, daphnia are not able to bite a person, their mouth apparatus is absolutely not adapted for this. Water fleas are used as feed for aquarium fish. Depending on the species, nutritional conditions, crustaceans contain from 50 to 70% protein. Fish are given them fresh, frozen or dried.
You can catch a “live feed” in any reservoir by means of a net or set up production at home. Water fleas in the aquarium will serve not only as food, but also purify the water.
The harm of crustaceans lies in their allergenicity. During the flowering of plants, pollen is carried by the wind and into the water. Daphnia in the process of filtering pass it through itself, as a result of which the allergen accumulates in them. In the process of drying, pollen remains and provokes strong allergic reactions, which are mistaken for bites.
Signs of Daphnia Allergy:
- the appearance of a rash on the body, similar in nature to the urticaria;
- severe itching;
- sneezing, nasal congestion;
- labored breathing;
- lacrimation, inflammation of the eyes.
To conduct an accurate diagnosis can only be a doctor on the basis of skin tests. Depending on the severity of symptoms, antihistamines and inhalers are prescribed.
Growing water fleas
In order to provide the inhabitants of aquariums with ecologically clean food, daphnids are grown at home:
- First of all, it is necessary to prepare a tank in which crustaceans will breed. It can be any plastic container suitable for food, plastic bottles from drinking water are often used.
- Crustaceans are not particularly demanding on the composition of water. The main thing is that it does not contain impurities of salts, metal compounds.
- Yeast and green algae are used as feed. The latter are actively developing in the sunlight. It is enough to put a bottle filled with water with the culture of microalgae in a warm place, as in 10-14 days it will be possible to feed water fleas “personally” with the grown feed.
- In order for the crustaceans to actively multiply, it is necessary to create favorable conditions for them: a temperature of 23-25 ° C and a 24-hour light day.
- Periodically daphnia culture and water update.
The highest nutritional value of fresh water fleas. In the frozen state, they lose some of the enzymes and amino acids.