Phylum: Arthropoda — Arthropods.
Subphylum Crustacea — Crustaceans.
Class Malacostraca — Malacostracans.
Order Decapoda — Decapods.
Infraorder Caridea — Caridean shrimp, true shrimp.
Superfamily — Alpheoidea, Atyoidea, Palaemonoidea.
Shrimp belong to the order of decapods (Decapoda), which also includes crayfish and crabs inhabiting fresh and marine waters. Many shrimp are found in the seas, while freshwater ones are a great rarity. Shrimp of many species are algae eaters and can “guard” the aquarium from algae for a long time. The specific names of freshwater shrimp popular among our aquarists need clarification. The fact is that shrimp have been repeatedly imported from natural water bodies of the Far East, China, India, and it was often difficult to identify them. Moreover, depending on the habitat conditions (in rivers or stagnant water bodies), some of them differ from each other even while belonging to the same species. Reddish-brown, fairly large shrimp (body length up to 12 centimeters) from Cuba have been imported into our country more than once. And in Europe, their own native shrimp was suddenly discovered — Atyaephyra desmaresti.
The family Atyidae includes: genus Atya (Leach, 1816), genus Atyaephyra (de Brito Capello, 1867), genus Atyoida (Randall, 1840), genus Atyopsis (Chace, 1983), genus Caridina (H. Milne-Edwards, 1837), genus Micratya (Bouvier, 1913), genus Neocaridina (Kubo, 1938), genus Paracaridina (Liang, ZL Guo & Tang, 1999). From the family Alpheidae, shrimp from the genera Alpheus and Potalmapheops are sometimes kept. From the family Desmocarididae, shrimp from the genus Desmocaris are kept. From the family Euryrhynchidae, shrimp from the genus Euryrhynchus are kept. From the family Palaemonidae, shrimp from the genera Palaemonidae, Macrobrachium, Palaemon are kept.
Freshwater shrimp are represented by several species. These are representatives of the genera Atya, Atyopida, Atyopsis, Caridina, Leander, Macrobrachium, Neocaridina, Palaemon, Palaemonetes. Most freshwater shrimp kept in aquariums originate from Asia. Their length, as a rule, does not exceed 6-8 cm. These fragile creatures remotely resemble a crayfish.
Shrimp are among the most intricate creatures that can be placed in a home aquarium. But unlike other, more clumsy inhabitants of aquariums from the subclass Malacostraca (which also includes crayfish and crabs), shrimp are distinguished by greater mobility and harmlessness to fish, and especially to aquatic plants and other landscape elements. Furthermore, the relative transparency of the carapace in some species wonderfully emphasizes grace and makes these cute creatures even more amusing and especially interesting to observe.
There are large species (some of them more closely resemble crayfish and only taxonomically belong to shrimp) which, growing in a small home aquarium, vigorously modify the underwater landscape, constantly dig up the substrate, and uproot decorative aquatic plants. Another problem is the exceptional voracity of large specimens. The large amount of food they require leads to an excessive accumulation of organics in the aquarium, which severely disrupts the ecological balance and leads to water clouding, algal blooms, and ultimately fish diseases.
When kept underfed, even predominantly predatory arthropod species are forced to supplement their diet with plants — while soft plants will disappear very quickly, the destruction of slow-growing Cryptocoryne and Anubias is just a matter of weeks. Secondly, despite the assurances of sellers (occasionally imported Asian and domestic Far Eastern freshwater shrimp are found on the market) that “they are peaceful and unpretentious.”
Special mention should be made of Macrobrachium. These “long-armed” predators require protein, and their victims become either shrimp, small fish, or sometimes, depending on the species, even snails. Therefore, a separate species aquarium or keeping them with large fish is recommended. Representatives of many even small species are quite aggressive and from early childhood constantly try to attack even larger fish. First of all, this applies to Leander from Lake Khanka. As for the giant river prawn (Macrobrachium rosenbergii), if an unwary fish suddenly ends up within reach of their claws, the inattentive fish has no chances. Rosenbergs have enough strength and determination to easily cope with a fish half their size. And considering that these animals reach their natural size of 40 cm in just a year even in a 100-liter aquarium, it becomes clear that introducing a Rosenberg to fish under 15-20 cm effectively signs a death warrant for the latter.
Fortunately, it is quite easy to distinguish a Rosenberg on the market (and recently they have been appearing more often and cheaper): despite significant similarities, Rosenbergs are given away by a prominent red “nose” (rostrum) with small serrations. Palaemon, if hungry, can also attack fish fry. Most often this happens when keeping conditions change. Thus, most of the large freshwater shrimp species offered to us on the market have limited suitability in large “office” aquariums with coarse lifeless substrate, gypsum-plastic decorations, and large (10-30 cm) fish such as cichlids.
Small shrimp of the genera Neocaridina or Caridina can be the salvation of an inquisitive aquarist. Usually, these shrimp are colored, and some species even quite intensely. Small freshwater shrimp are very peaceful inhabitants of decorative aquariums. Most of the time they leisurely scurry along the substrate and decorative elements of the water body in search of food.
When buying shrimp, the shape and color should be typical of the variety, and the coloration should be bright. Transparent shrimp should have some white or gray pigmentation inside the body, and they should not have milky pigmentation. Red, bloody spots may be a symptom of a dangerous disease. White, striped streaks on the carapace indicate symptoms of a viral disease. You should not buy adult shrimp. Their lifespan is very short, and when buying adult shrimp, it will be difficult for you to guess their real age. Prepare for the purchase by studying the literature and photographs of the desired shrimp species, otherwise a seller might sell you a beautiful, small shrimp that will grow up to 20 cm and destroy vegetation and fish.
When transporting, two or three blades of grass, a sponge, or a piece of net should be thrown into the container with shrimp — shrimp are very delicate, they do not tolerate rocking at all, and they definitely need something to hold onto. The amount of air in the container should be at least twice the amount of water. It is important that the container has a curved bottom without corners. Varieties of the genus Macrobrachium are generally more resistant to transport if oxygen is present in the water and their number is not too large. Also, do not transport too many males in one container. Caridina/Neocaridina and filter-feeding shrimp are much more sensitive.
Try not to buy females with eggs, because it is very possible that they will survive the trip but die after being placed in the tank. The water temperature should not change rapidly during transport, with overheating being much more dangerous than a drop in temperature. If we know that the transport will be long, then we need to prepare a container lined with expanded polystyrene.
When placing shrimp into the aquarium, they must be allowed to acclimatize by placing the bag with them for 30-60 minutes in the aquarium water and gradually adding water from the same aquarium into it. If we place shrimp in water with a high pH, their bodies may turn white. If there are fish in the aquarium, they may mistake them for food, so turn off the light for 2-3 hours or release them at night when the fish are sleeping. At this time, their color may change due to stress, but it will recover in a few hours.
Usually, neutral water of medium hardness is quite suitable for most shrimp species. However, some species prefer slightly acidic or moderately alkaline water. In most cases, acceptable initial conditions are pH ranging from 6.5 to 7.5 and hardness around 10° dH. Nevertheless, regarding specific species, it is recommended to check the most suitable water parameters for them. When changing water, it is important to try to match the fresh and previous water in terms of hardness and temperature values. For shrimp, this is even more critical than for fish.
A big problem when keeping shrimp is copper. Medications containing copper should not be used in an aquarium with them. Some manufacturers warn about this in the instructions, advising to reduce the concentration, but without experience, it can sometimes be difficult to measure the correct dose, and as a result of exceeding the MPC of copper, the shrimp die. Moreover, this may not happen immediately, but within 1-2 weeks.
The bottom area is even more important than the actual volume of the aquarium, since shrimp can be successfully kept in small containers. But we must not forget that in large aquariums it is easier to maintain the stability of water parameters. Therefore, using containers with a volume of less than 25 liters is not recommended. It is necessary to provide shelters at the bottom in the form of leaves, stones, or driftwood. For a shrimp aquarium, simple aquatic plants that do not require special care for active growth are probably best. On them, shrimp find enough algae and biological films for their nutrition. It is much more difficult to successfully keep shrimp together with more demanding plants, the cultivation of which requires fertilization and algae removal, as a result of which the natural food sources of shrimp suffer. Moderate lighting is recommended for keeping shrimp, as well as the absence of water enrichment with carbon dioxide and refraining from adding fertilizers to the water (using nutrient substrate is permitted).
Any large fish frighten shrimp, regardless of whether they are predators or not. In principle, any fish with a mouth size proportional to the shrimp is very likely to eventually swallow one of them. And when shrimp begin to be associated with food by fish, they will quickly catch all the shrimp. If you are going to breed shrimp, it is better to keep them separate from fish, because the juveniles are so small that they eventually fall victim to even the most peaceful ones. There are cases of dwarf crayfish attacking dwarf shrimp. And, needless to say, small shrimp invariably become victims of Macrobrachium.
In dwarf shrimp, males and females can often be distinguished by body shape. Females have expanded abdominal segments, making it easier to carry eggs. They are larger and brighter than males. Males usually have longer antennae. This is especially pronounced regarding the second pair of shorter antennae. However, in some species, this approach is not enough to determine sex, and for reliability, one has to look at the genital openings. In females, they are located in the lower part of the sixth body segment, and in males — between the sixth and eighth segments. However, in shrimp 2-3 centimeters in size, it is difficult to see and localize the genital openings.
In Macrobrachium, males and females are usually easiest to distinguish by the first pair of clawed limbs, which are larger in males. As a rule, sexually mature individuals also differ significantly in overall body size. Male fan shrimp have a larger first pair of walking legs, and females have an expansion of the carapace in the abdominal region, facilitating egg incubation.
In some shrimp species, miniature copies of adults hatch from eggs. In others, free-swimming planktonic larvae emerge from the eggs. This planktonic stage in the reproductive cycle requires an increase in water salinity and the presence of fine suspended particles to feed the larvae until they reach the juvenile stage.
Gradation of Crystal Red, Crystal Black shrimp by classes.
