Today we do not come to talk about a fish itself, but we will talk about a highly valued and well-known species. It's about the Caridina japonicaIt is a species of freshwater shrimp that is in high demand and famous for both its ornamental value and its usefulness in controlling pests. filamentous algae. It belongs to the Atyidae family and is of Japanese origin.
Would you like to know all the characteristics, way of life and reasons why it is so in demand? You just have to keep reading
Key features
This species of freshwater shrimp can be found in shallow waters of ponds and lagoons. They can live in freshwater environments, but also tolerate higher salinity. Its natural habitat is in the Yamato region, although some populations can be found in the locations of Cora and Taiwan.
Due to its widespread popularity at the Takashi Amano water park for its landscaping properties, its use in aquariums has become widespread. It is commonly known as the Amano shrimp.
Speaking of its morphology, we can say that its body it is similar to the rest of prawns both marine and freshwater. It has a cephalothorax with a white stripe that ends on the tail. This is perhaps the most distinctive part of the prawn. In the part of the head we find all the organs that are vital for the survival of the animal. In this area we find four pairs of legs to use to move.
The skeleton receives the exoskeleton name And beneath it, we find the abdomen and its muscles. Here, it has a kind of skirt that it uses for swimming. Its tail has several distinguishable black and white spots and is made up of pleopods. These elements are used to abruptly change direction when swimming and being pursued by a predator.
La Caridina japonica it has the majority of its transparent body. Its coloration is capable of varying as a consequence of its type of diet. The difference between males and females lies in the spots that decorate it. While the females have their spots longitudinally, the males have them spread out in no apparent order.
An important nomenclature fact: in aquaristics it is still very well known as Caridina japonica, but its valid scientific name is Caridina multidentataYou'll find both names in stores and literature, referring to the same invertebrate.
Needs and your environment
If we talk about its size, we can say that it reaches a size of about 6 centimeters in females and only 3 cm in males. This makes it stand out from other Caridina species. For example, in the species caridina cantonensis, specimens reach sizes of up to 9 cm. These animals originate from China and their common spots are smaller.
One of the factors to take into account to keep the Caridina japonica it is their feeding phase in the aquarium. He should not be given a lot of food at once, rather, it should be done slowly. In addition, it is vitally important to feed them with the light off to reduce stress in these animals.
They aren't usually aggressive animals, so they can be kept in small groups. This way, we'll help them gradually lose their natural shyness. If we stress them too much and don't let them overcome their shyness, we'll barely be able to see them. They work at night, although if the light isn't too strong, they'll also be active during the day.
As a guide to the type of aquarium, they adapt well to landscapes with rocks, logs, and plants. In aquariums with logs, tannins and cellulose can cause them to take on a more brownish tone, which is normal and aesthetically pleasing. It is advisable to have java moss and refuge areas so they feel safe, especially during moulting.
Recommended water parameters based on the experience of top keepers:
- Temperature: 18-28 ºC, with an approximate optimal range of 22-26 ºC.
- pH: 6,5-7,5 (neutral to slightly alkaline).
- GH: 5-15; KH: 2-8.
- TDS: wide tolerated range, provided that the stability be the priority.
- Oxygenation: high; avoid detectable ammonia and nitrites.
They are sensitive to copper and heavy metals, and medications containing them. Avoid medications and products not specifically designed for invertebrates. If in doubt, perform a water change and use conditioners that neutralize chlorine and metals.
Meals
A vegetable supplement plays a leading role in your diet. It is a filamentous algae and not the typical black or brush algae. It is generally tolerant of other plants if it does not have food. They have also been found feeding on Riccia. If they are hungry they can eat anything they find. It has even been seen eating dead animals and larvae. de peces.
In aquariums, their feeding must be subject to their effectiveness as a filamentous algae controller.
One of the most important aspects to take into account if we decide on this species is the importance of choosing good aquarium mates. These shrimp are not good companions de peces Large, aggressive creatures. If placed with them, they won't hesitate to eat them as food.
As an algae eater, excels at hair algae (short, medium, and long filamentous algae), but does not consume red algae such as brush, staghorn, or hydras. If the filamentous green algae are already very long and dense, they may lose interest; a trick is prune them so they will eat the tender shoots again. Supplement with specific shrimp diets (pellets, spirulina, catappa leaves) and cooked vegetables such as zucchini or spinach in small portions, removing what is not consumed within a few hours.
Reproduction of the Caridina japonica
As for its reproduction, it is perfectly viable in captivity. We must take extreme caution to keep the female in another aquarium before the eggs hatch. Otherwise, the rest of the fish in the tank will have a food rich in protein. They reach sexual maturity after 5 months of life. It is possible to detect that the female is pregnant if her belly turns dark. This is the signal that tells us that the eggs are beginning to form.
Depending on the water temperature, the hatching of Eggs take an average of 4 to 6 weeks. Adult shrimp can live perfectly in freshwater. However, the larvae need sea water Initially, this is necessary for their development. The ideal salt ratio is 30 grams per liter of water. When they reach a size greater than five millimeters, they must be prepared for transfer to freshwater. To do this, add water little by little to reduce the amount of salt. Larvae should never be transferred suddenly from saltwater to freshwater.
The feeding of the Caridina japonica hatchlings is based on live or commercial plankton. They can also be fed brine shrimp or cypclop eeze nauplii. Once they have grown above 1,5 centimeters they can be incorporated into the general aquarium with their companions. If it is important that the other fish are not large or they will end up eating them.
Their life expectancy is close to 3 years, although it does not usually exceed two in captivity.
Bring realism to the hobbyist: although there is an effective breeding protocol (brackish water for larvae and gradual return to fresh water), It is not a simple projectMany aquarists fail to achieve high survival rates without equipment and strict discipline in salinity, nutrition and gradual changesIf you are attracted to breeding, prepare two urns (fresh and brackish), plan the drip acclimatization at each transition and maintain gentle lighting and flow to prevent larvae from being sucked into the filter.
Compatibility, recommended number and behavior
Its peaceful and can live with small and calm species: small tetras, guppies, dwarf corydoras, otocinclus and snails. Avoid large cichlids, territorial bettas, or other fish that might see them as food. In communities, the denser and more planted the tank, the better the chances of fry thriving.
It is recommended to introduce them when the aquarium is already stable. Many aquascapers add them from the day 15 of assembly to tackle cycling algae, as long as the nitrites are decliningAs a reference for population density, they work well. 5-6 specimens per 30 liters, about 10 for 60 liters and 30 to 50 for large aquariums of 180-240 liters, gradually increasing according to biological load and biofilm availability.
In a group they feel safer and they graze together on surfaces with biofilm. They are active feeders and will take advantage of any organic debris, contributing to the balance of the ecosystem.
Aquarium preparation and good practices
Before introducing them, make sure the aquarium is cycled and with stable parameters. In its installation, it prioritizes filters with high biological capacity and avoid sucking up young by adding sponges or fine mesh to the entrance. Oxygenation and gentle surface movement are key to their well-being.
La drip acclimatization This is the safest method to reduce stress from parameter changes: use a thin tube and drip 2-3 drops per second for several hours until TDS and temperature equalize. Avoid sudden water changes; few and regular (15-30%), always equalizing temperature and, if you remineralize, the TDS.
If you use CO2 in plantations, make sure it does not cause strong pH fluctuations. And remember that medications or treatments with copper They are dangerous for invertebrates. Wash plants and hardscape before introducing them to avoid contaminants.
Takashi Amano and the role of the Amano shrimp
The popularization of this species in planted aquariums is due to the approach of Takashi Amano, who integrated the Caridina japonica , the natural algae control tool and a functional piece within balanced ecosystems. Its transparency and brown dots do not distract from the composition; on the contrary, add life and dynamism while cleaning surfaces and leaves.
Beyond algae control, their presence stimulates ecological balance: by consuming detritus and organic matter, they reduce waste accumulation and promote aquarium stability.
Common mistakes to avoid
- Overcharging: generates spikes in ammonium and ammonia. Feed small portions and remove excess.
- Abrupt changes: in temperature, pH, or TDS cause stress and declines. Opt for moderate, stable changes.
- Use of copper: Many anti-parasitic products contain it; avoid any product not suitable for invertebrates.
- Lack of oxygen: High temperatures reduce dissolved O2; aeration increases in summer.
An additional tip: if the filamentous plants are out of control, combine their work with manual maintenance, nutrient control, and adjusted photoperiod. Shrimp are a magnificent help, but they require an environment that isn't unbalanced from the start.
quick questions
- When to introduce them? With the aquarium cycled; some add them mid-cycle if the nitrites are already dropping.
- How many per liter? As a reference, 5-6 per 30L and scale from there.
- Do they eat all algae? No; they excel at filamentous plants. They don't consume paintbrush (red/black), staghorn, or hydras.
- Do they breed in sweet? The larvae require salt water. It's possible with the right technique and resources, but it requires experience.
As you can see, the Caridina japonica is a shrimp that is in high demand by all those who love aquaristics. Not only for its function in controlling filamentous algae, but because it adds a distinct beauty to the aquarium it's in. Have you ever thought about owning one of these?
Choose the Caridina japonica is to opt for a resistant, useful and aesthetically discreet invertebrate that enhances any planting. Keeping it in groups, with good biofilm, stable parameters and oxygenationYou'll see how it tirelessly herds and keeps filamentous insects at bay. In the hands of hobbyists and aquascapers, it remains one of the best allies for achieving clean, healthy aquariums with engaging, natural activity.
