The Amano shrimp (Caridina multidentata) is a standout choice for freshwater tanks, known for its exceptional algae-cleaning abilities. This shrimp is a valuable addition to any aquarium, especially planted tanks and aquascapes, where it helps maintain a clean and beautiful environment by consuming hair algae. Amano shrimp are not only effective cleaners but also add an intriguing dynamic to the tank with their active, peaceful behavior. Their presence enhances both the functionality and visual appeal of your aquatic setup.
Contents
Habitat in the wild
In 2006, scientific studies revealed that two previously classified species, Caridina japonica (described in 1892) and Caridina multidentata (described in 1860), are actually the same. Consequently, the official name was updated to Caridina multidentata.
The Amano shrimp, named after renowned aquascapist Takashi Amano, gained popularity in the aquarium world due to its algae-eating prowess. In the 1980s, Takashi Amano highlighted this shrimp’s exceptional ability to clean planted tanks, leading to a surge in its use. He famously ordered thousands of these shrimp from local suppliers to address algae problems in his aquascapes, which is why they are commonly known as “Amano shrimp.”
In the wild, shrimp are found in clean freshwater rivers and streams in southern Central Japan, South China, and, more recently, Taiwan. Their life cycle is fascinating and complex: while adults live in freshwater, their larvae hatch in the sea, where they feed on plankton before returning to freshwater as they mature. This unique life cycle poses challenges for breeding Amano shrimp in captivity.
In their natural habitats, shrimp face threats from various predators, including fish, birds, and larger invertebrates. Their translucent bodies and coloration help them blend into their surroundings, offering some defense against these predators.
Description
Amano shrimp are notably larger than cherry shrimp. Males typically grow to about 1.5 inches (3-4 cm), while females reach up to 2 inches (5-6 cm). Their bodies are mostly transparent with tiny red-cinnamon spots, which can change color depending on their diet. For instance, if shrimp primarily consume algae and detritus, they may develop a greenish tint. Conversely, a diet of only fish food tends to give them a reddish hue.
These shrimp have an elongated, cylindrical body with a distinctive curved rostrum (or nose). Their translucent bodies often show a mix of brown and greenish hues, allowing internal organs to be partially visible. The intricate patterns of stripes, spots, and speckles on their bodies add to their captivating appearance.
Amano shrimp are masters of camouflage. When they choose to hide, it can be quite challenging to spot them. There have been instances where owners, believing their shrimp had perished, found them safe and sound after draining the tank. A helpful tip to locate hidden shrimp is to shine a flashlight on the tank bottom at night; the shrimp’s eyes will reflect the light and shine brightly.
Their long, slender antennae aid in navigating their environment and sensing changes. Additionally, shrimp have delicate, branching appendages called pleopods, which assist in swimming and carrying eggs for females.
How Fast Do Amano Shrimp Grow?
Amano shrimp grow relatively slowly compared to some other freshwater shrimp species. On average, it takes them about 6 to 12 months to reach their full size of approximately 2 inches (5 centimeters). Individual growth rates can vary based on genetics, diet, water conditions, and overall care.
During their growth, shrimp molt, shedding their old exoskeletons to accommodate their increasing size. After molting, they may appear softer and more vulnerable until their new exoskeleton hardens. Growth is often most noticeable during these molting periods.
| Characteristic | Description |
|---|---|
| Scientific Name | Caridina multidentata, Caridina japonica |
| Common Name | Amano shrimp, japonica shrimp, yamato shrimp |
| Origin | Japan and Taiwan |
| Size | Approximately 2 inches (5 centimeters) in length |
| Coloration | Translucent body with brown or greenish markings |
| Behavior | Peaceful and social, often found in groups or colonies |
| Lifespan | Around 2 to 3 years in captivity |
| Diet | Algae, detritus, decaying plant matter, and small invertebrates |
| Molting | Shed their exoskeleton to grow a new one |
| Breeding | Challenging in home aquariums due to complex larval stages requiring brackish water |
| Compatibility | Generally compatible with a wide range of tank mates |
| Aquascaping | Suitable for planted tanks and aquascapes |
| Water Parameters | Neutral to slightly alkaline pH, moderate hardness |
| Temperature Range | 70°F to 80°F (21°C to 27°C) |
| Lighting | Moderate to low lighting preferred |
| Tank Size | Can be kept in aquariums as small as 5 gallons |
| Predation | Vulnerable to predation by fish, birds, and larger invertebrates |
| Environmental Role | Controls algae growth, recycles nutrients, and serves as a food source |
Algae eating shrimp
Caridina multidentata have gained popularity among aquarists due to their remarkable algae-eating abilities. Takashi Amano, a renowned aquascaper, initially introduced these shrimp to his tanks to tackle algae issues that were hindering his perfect aquascapes. Amano shrimp are highly effective at consuming hair algae, which can be a persistent problem in aquariums.
These shrimp excel at cleaning green hair algae from tank plants, moss, and decorations. Green hair algae can quickly spread in the same conditions that favor decorative plants, creating thin filaments that can overtake the tank. Removing algae by hand is laborious and often ineffective, as it regrows quickly. This is where Amano shrimp become invaluable.
Using their small, specialized chelae (claws), shrimp pick at the algae piece by piece, significantly reducing the need for manual cleaning. They are especially adept at handling filamentous algae, making them an excellent addition to any tank where this type of algae is a concern.
For optimal effectiveness, it is recommended to have at least 4 Amano shrimp per 20 liters (5 gallons) of water.
However, it is important to note that shrimp do not consume all types of algae. They do not feed on black beard algae or brown algae. While they may nibble on black beard algae occasionally, they will not eliminate it entirely.
To manage black beard algae and brown algae, additional algae-eaters should be included in the tank. Species such as Siamese algae eaters (SAEs) are effective against black beard algae, while bristlenose plecos, Chinese algae eaters, and nerite snails can help control brown algae.
In summary, Amano shrimp are highly effective for managing green hair algae but should be complemented by other algae-eaters to address a wider range of algae problems in your aquarium.
Difficulties in keeping
Amano shrimp are an excellent choice for aquarium enthusiasts. They are easy to care for, non-threatening to other fish, and will consume a variety of foods. For a thriving group of shrimp, it’s best to keep at least 10 of them together, as they enjoy the company of their own kind.
One key aspect of keeping Amano shrimp is maintaining stable water conditions. They are sensitive to changes in water parameters, and sudden shifts, such as those caused by water changes, can be harmful.
When starting a new aquarium, it’s important to wait until the tank has fully matured before adding Amano shrimp. This usually means waiting at least two weeks after setting up the tank. During this time, ensure that the biological balance, pH levels, and CO2 supply are stable and that the biological filtration is properly functioning. This will help create a suitable environment for your shrimp to thrive.
Care and keeping in a tank
Lifespan
On average, Amano shrimp live for about 2 to 3 years in captivity. However, under optimal conditions, they can reach up to 5 years.
It’s important to note that shrimp sometimes die shortly after being purchased or after a water change. This is usually due to the stress of acclimating to new tank conditions or sudden changes in their environment. Proper care and stable conditions can help maximize their lifespan.
Tank size
The tank volume for Amano shrimp should be chosen based on their number, with a recommended minimum of 5 liters per shrimp. Ensure the tank is covered and all large openings are sealed to prevent the shrimp from escaping.
For a 25-gallon tank that is densely planted and has a fine-grained substrate, you can comfortably keep around 20 shrimps. These shrimp thrive in the company of their own kind, so maintaining a group of at least 10 will allow you to observe their fascinating social interactions.
Water parameters
Amano shrimp are relatively easy to care for and adaptable to various tank conditions, but they thrive best when water parameters are stable.
Water Parameters:
- Temperature: The optimal temperature range is between 73-82 °F (23-27 °C). They can tolerate temperatures as high as 86 °F and as low as 60 °F (14-16 °C). However, higher temperatures can speed up their metabolism, leading to faster aging.
- pH Level: prefer a pH range of 5.8 to 7.0. If the pH exceeds 7.5 and oxygen levels are low, the shrimp may become stressed and try to escape the tank.
- Ammonia Tolerance: Unlike some other shrimp species, they are not highly sensitive to ammonia, but maintaining low ammonia levels is still important for their health.
Water Changes: Regular water changes are crucial for the health of shrimp. Aim to change 20-30% of the tank water weekly. Adding slightly cooler water, 2-3 °C colder than the tank water, can stimulate the shrimp to become more active and potentially encourage breeding.
Brackish Water: It’s important to note that Amano shrimp are strictly freshwater creatures. They only encounter brackish water during their breeding phase before returning to freshwater environments.
Tank setup: decorations and plants
Shrimps, especially females, will be very glad to find some shelters in the tank – snags, small branches, tank plants with large leaves will do perfectly well. Female with eggs is very attractive for active male shrimps, and they haunt them rather aggressively. Therefore, you should provide the female shrimps with the ability to hide somewhere from their obstinate admirers.
Tank plants with small leaves will look nice and appealing as well. Java moss, christmas moss, flame moss, dwarf hairgrass, blyxa japonica, egeria densa, marimo moss balls, vallisneria are good choices for a shrimp tank. These plants are an ideal place for small tank dwellers to hide, and they accumulate food for them as well. Lots of suspended particles, mud, food leftovers settle there and then become home for algae.
Amano shrimps, especially young ones, love eating all the food mentioned above. Java moss creates perfect conditions for microorganisms to live (those that feed on bacteria). Water sprite will be another good choice for such a tank as well. This plant isn’t demanding as for the tank lighting, and its root system is very similar to that of the moss.
You must be careful when cutting the plants and removing them from the tank. Since together with them you can throw away a shrimp sitting on it.
The same situation may occur when weeding fluctuant on the tank water surface (amazon frogbit, water lettuce). Amano shrimps often sit on the leaves bottom.
Filtration
For keeping and breeding Amano shrimp, a tank equipped with a canister filter is an excellent choice. Here’s why:
Canister Filter Benefits:
- Efficient Filtration: Canister filters provide thorough filtration, ensuring that water remains clean and clear.
- Biological Filtration: Over time, waste accumulates in the canister filter, creating a rich environment for beneficial bacteria. These bacteria help to break down waste, improving water quality and stabilizing the tank’s ecosystem.
Alternative for Smaller Tanks:
Internal Filter: If you have a smaller tank, an internal filter can be a suitable alternative. While it may not offer the same level of filtration as a canister filter, it still provides essential water movement and filtration.
Why did my Amano shrimp die?
Transporting: Improper transport can cause stress and shock to your shrimps. To ensure their safety during long journeys, include some moss or pieces of foam in their transport container. This provides them with something to hold onto and helps minimize stress.
Avoiding Copper Toxicity: Do not use medications containing copper sulfate (CuSO4) or overdosing liquid fertilizers in your tank. Copper can be harmful or even fatal to shrimp. Always check the ingredients of any treatments or fertilizers before adding them to your tank.
Acclimation Process: When introducing shrimp to a new tank, gradual acclimation is crucial. To prevent shock, slowly adapt the shrimp to the new water conditions by adding small amounts of tank water to their transport container over a period of 2-3 hours. Sudden changes can cause serious stress and potentially lead to death.
Maintaining Stable Water Parameters:
- pH and Ammonia: Rapid changes in water parameters, especially pH and ammonia levels, can be harmful. After cleaning your filter, only wash one-third of the filter material at a time to avoid spikes in ammonia.
- Carbon Dioxide (CO2): Excess CO2 can negatively impact shrimp health. Monitor their behavior closely if you are using CO2 in your planted tank. If shrimp become lethargic or stop eating, check CO2 levels.
Calcium and Oxygen Levels:
- Calcium: A lack of calcium, particularly noticeable after molting, can be detrimental. If using osmosis water, mix it with tap water in a 4:1 ratio or add calcium supplements to increase water hardness.
- Oxygen: Ensure that your tank has adequate oxygen levels. Insufficient oxygen can lead to shrimp mortality.
Preventing Chlorine Poisoning: Chlorine and chloramine in tap water can be harmful to shrimp. Use a water conditioner that contains sodium thiosulfate to neutralize these chemicals and ensure the safety of your shrimp.
Feeding
The whole day shrimps go around the tank looking for food, touching each stone and leaf, and when they find algae, they cut them with their small chelae.
The best food is specialized food for shrimps, vegetables like cucumber or squash, flakes, pellets, live and frozen food. In general, the shrimps aren’t demanding as for the food, although you should buy food with high content of dietary fiber. They can feed on dead fish, snails. The shrimp likes spending its time on bulbs of moss or sponges of internal water filters. In this case, they feed on fish, food leftovers, and detritus. They don’t eat moss.
Besides, shrimp rather efficiently eats fish food leftovers, especially if you keep some gluttonous fish in the tank. Don’t forget to give the shrimp some additional food, especially if there isn’t much algae and detritus in the tank. Amano shrimp is a rather large one, and it should have a proper diet.
When shrimps are full, they become less active. Usually, they sit on some high spots and expose their body to the water flow rich in oxygen created by the filter. They demonstrate the same behavior after shedding.
Tank mates
Amano shrimp is peaceful. The shrimp feels comfortable in a common tank. However, they may become prey for some large fishes. Therefore, you shouldn’t keep shrimp with large cichlids (like jaguar cichlid or Texas cichlid, as well as with angelfish, especially if shrimps are little), with large catfish (redtail catfish, striped raphael catfish, sun catfish, upside-down catfish) and goldfishes.
| Fish Species | Size | Temperament | Tank Size (Minimum) | Additional Notes |
|---|---|---|---|---|
| Betta (Siamese Fighting Fish) | Small to medium | Aggressive | 5 gallons | Known to be aggressive towards shrimp and may hunt them |
| Angelfish (Pterophyllum spp.) | Medium to large | Semi-aggressive | 30 gallons | Can see shrimp as food and may prey on them |
| Dwarf Gourami (Trichogaster spp.) | Small to medium | Semi-aggressive | 15 gallons | Can be territorial and may harass or nip at shrimp |
| Goldfish (Carassius auratus) | Medium to large | Semi-aggressive | 20 gallons (per fish) | Highly likely to eat shrimp due to their large size and appetite |
| Rainbowfish (Melanotaenia spp.) | Small to medium | Semi-aggressive | 20 gallons | Can be nippy and may harass shrimp |
| Tiger Barb (Puntigrus tetrazona) | Small to medium | Semi-aggressive | 20 gallons | Known to nip at shrimp and may stress or injure them |
| Red-tailed Shark (Epalzeorhynchos bicolor) | Medium to large | Semi-aggressive | 30 gallons | Can be territorial and may harm or stress shrimp |
| Jack Dempsey (Rocio octofasciata) | Large | Aggressive | 55 gallons | Highly aggressive and will prey on shrimp |
| Oscar (Astronotus ocellatus) | Large | Aggressive | 75 gallons | Very large and predatory fish, will eat shrimp |
Amano shrimp gets on well with any small-sized peaceful fishes since they are peaceful themselves, too. However, when feeding, they may steal food from each other and other fishes, which looks rather funny. Nevertheless, you should still keep an eye on them and make sure that every shrimp gets enough food.
| Fish Species | Size | Temperament | Tank Size (Minimum) | Additional Notes |
|---|---|---|---|---|
| Neon Tetra (Paracheirodon innesi) | Small (1.5 inches) | Peaceful | 10 gallons | Active and colorful, should be kept in groups |
| Ember Tetra (Hyphessobrycon amandae) | Small (1 inch) | Peaceful | 10 gallons | Vibrant red coloration, should be kept in groups |
| Green Neon Tetra (Paracheirodon simulans) | Small (1 inch) | Peaceful | 10 gallons | Similar to Neon Tetras, but with a greenish-blue stripe |
| Harlequin Rasbora (Trigonostigma heteromorpha) | Small (2 inches) | Peaceful | 10 gallons | Active and colorful, should be kept in groups |
| Phoenix Rasbora (Boraras brigittae) | Very small (0.8 inch) | Peaceful | 5 gallons | Beautiful red coloration, should be kept in groups |
| Endler’s Livebearer (Poecilia wingei) | Small (up to 1.5 inches) | Peaceful | 10 gallons | Colorful and active, males have striking patterns |
| Celestial Pearl Danio (Danio margaritatus) | Very small (0.75 inch) | Peaceful | 10 gallons | Delicate and colorful, requires well-established tank |
| Otocinclus Catfish (Otocinclus spp.) | Small (1.5 to 2 inches) | Peaceful | 10 gallons | Algae eaters, gentle and non-aggressive towards shrimp |
| Corydoras Catfish (Corydoras spp.) | Small to medium | Peaceful | 20 gallons | Bottom dwellers, gentle and non-aggressive towards shrimp |
Amano shrimp and cherry shrimp
Despite conflicting information online, I’ve successfully kept Amano shrimp and cherry shrimp in the same tank. In my experience, they do not eat adult cherry shrimp. The only scenario where this might occur is if the Amano shrimp are starving, but this is unlikely as their chelae are designed for cutting algae, not for attacking other shrimp.
Compatibility:
- Behavior: Amano shrimp are generally peaceful and don’t pose a threat to cherry shrimp. They are more focused on algae cleanup rather than preying on other shrimp.
- Care Requirements: While Amano and cherry shrimp can coexist, they have different care needs. It’s crucial to ensure that the tank conditions meet the requirements of both species for them to thrive.
| Characteristic | Amano Shrimp | Cherry Shrimp |
|---|---|---|
| Scientific Name | Caridina multidentata | Neocaridina davidi |
| Appearance | Translucent body with brown or greenish markings | Wide range of colors, including red, blue, yellow, and more |
| Size | Approximately 2 inches (5 centimeters) | Around 1 inches (2.5 centimeters) |
| Behavior | Active foragers, primarily eat algae and organic matter | Active scavengers, can eat algae and detritus |
| Feeding Habits | Strong preference for algae, also eat detritus and small invertebrates | Omnivorous, eat algae, detritus |
| Availability | Widely available in the aquarium trade | Widely available and popular in the aquarium trade |
| Cost | Generally more expensive | Generally more affordable |
| Lifespan | Around 2 to 3 years | Around 1 to 2 years |
| Water Parameters | Prefer slightly alkaline water with moderate hardness | More adaptable to a wide range of water parameters |
| Breeding Challenges | Challenging due to complex larval stages and brackish water requirements | Relatively easy to breed in freshwater aquariums |
Amano shrimp vs ghost shrimp
Amano shrimp (Caridina multidentata) and ghost shrimp (also known as glass shrimp) (Palaemonetes spp.) are both popular freshwater shrimp species in the aquarium hobby. Are Amano shrimp and ghost shrimp the same? No. These are two different shrimp kinds, even though they have a similar appearance. At that, they can live together in one tank.
| Characteristic | Amano Shrimp | Ghost Shrimp |
|---|---|---|
| Scientific Name | Caridina multidentata | Palaemonetes spp. |
| Appearance | Translucent body with brown or greenish markings | Transparent, glass-like appearance |
| Size | Approximately 2 inches (5 centimeters) | Around 1.5 inches (3.8 centimeters) |
| Compatibility | Generally peaceful and compatible with a variety of tank mates | Generally peaceful, but may exhibit aggression and territorial behavior |
| Behavior | Active foragers, primarily eat algae and organic matter | Scavengers, opportunistic feeders |
| Feeding Habits | Strong preference for algae, also eat detritus and small invertebrates | Feed on algae, detritus, and small invertebrates |
| Cost | Generally more expensive | Generally more affordable |
| Lifespan | Around 2 to 3 years | Around 1 to 2 years |
| Breeding Challenges | Challenging due to complex larval stages and brackish water requirements | Can breed in freshwater aquariums |
Gender differences: male vs female
Females have their first line of spots on the abdomen transferred into small lines, but male shrimps still have spots there. A shrimp male is smaller than a female. It is about 1.5 inches large (3.5-4 cm). The female shrimp grows to become a little larger – up to 2 inches (4-5 cm).
If you see not uniformly spread red-cinnamon round spots on the shrimp body sides – this is definitely male. A mature female has pronounced long pleopods on its abdomen.
Breeding
The shrimp lives in rivers and streams that flow into the sea. Unlike red cherry shrimp, whose eggs hatch to show small shrimps looking like the adult ones, Amano shrimp hatches as larvae. They roll to brackish waters and live there for 3-6 weeks, filter plankton unicellular algae, and pass through several steps of development up to the last one. Then small shrimps go to freshwaters where they will live during their whole life. They become reproductive in about 6 months since they hatch.
To achieve success in Amano shrimps breeding, you should take the shrimp larvae and then the juveniles through the stages of water salinity, corresponding to their migration through different kinds of water in the wild.