Amano Shrimp: Everything You Need To Know!

Amano Shrimp (Caridina multidentata) are popular freshwater shrimps that are semi-transparent with reddish broken lines on the sides of their body. They might not be the most beautiful type of caridina but they are definitely one of the best algae-eating shrimps in the world. 

These shrimps are known to get aggressive towards other fish and jump out of the tank when they are under stress. Because of this, it is important to be prepared for any behavioral issues these shrimps might develop. In this article, we guide you through all the information you need to successfully care for Amano Shrimp.

Amano Shrimp Overview

Endemic to Japan and parts of Taiwan, the Amano Shrimp were first introduced to the aquarium hobby by Takashi Amano in the early 1980s. Mr. Takashi Amano first used these shrimps in his aquascapes to keep the tanks clean and algae-free. Since then they have become one of the most sought-after shrimps in the aquarium hobby.

In the past, these shrimps were called Caridina japonica but after a study in 2006, the scientists renamed them Caridina multidentata. Amano shrimps or Caridina multidentata shrimps are also known by other names like Yamato shrimp, Yamato Numa Ebi, Swamp Shrimp, Japanese shrimp, Japanese Marsh Shrimp, and algae shrimp. 

These shrimps are known to be one of the best algae-eating creatures you can get for your tank. At the same time, they are one of the hardier types of caridina shrimps which makes them a great choice for most aquarium setups. 

Unlike some other caridina shrimps, almost all the Amano shrimps you see in pet stores are collected from nature. This is because they are slightly hard to breed, which makes them expensive and time-consuming to breed in captivity at scale.  

Appearance

Amano shrimp are semi-transparent freshwater invertebrates that have broken red lines on the sides of their body. Unlike other caridina shrimps in the hobby, the Caridina multidentata or Amano shrimps are colorless and slightly bold in body size. 

Amano shrimps have been in the aquarium hobby for quite some time now but have not yet been line bred to create more morphs and patterns. This is mainly because of the harder process of breeding these species and the fact that they are not available in large numbers around the world.  

Unlike ghost shrimps, Amano shrimps have color pigments in their body that can become more colorful if they are being fed the right type of food. When they eat a diet enriched with fresh algae they will become more greenish but they still remain semi-transparent. Usually, these shrimps have a gray and brownish tint on their body. 

At the same time, like most shrimps, they will try to match their body color with their surroundings to camouflage. When you keep them in highly planted aquascapes they will slowly develop a greenish tint whereas if kept in plantless escapes they will remain gray. 

Lifespan

Amano Shrimp’s lifespan is around two to three years. This puts them in the realm of shrimps that live a longer life. However, keeping Amano shrimps alive for that long needs expertise. Most shrimp will die due to inconsiderate actions by the new shrimp owners. These shrimps need stable tank parameters that don’t change.

If you keep your Amanos at lower temperatures and house them with peaceful fish that doesn’t bother them, they will live a long and happy life. Higher temperatures will raise the metabolism in Amano shrimps and will shorten their lifespan. 

Adult Size

Amano Shrimp can grow to about 2 inches in length. They will reach this size after some time so when you first buy them at the pet store they will probably be at around the 1-inch mark. The females are usually bigger and more round than the male specimens. 

Even though these shrimps are mainly coming from the wild, it seems like they are collecting the younger specimens and leaving the larger ones to breed. Amano shrimps are chunkier than most shrimps in the Caridina family. 

Behavior and Temperament

Amano Shrimp are generally peaceful species. However, they might show aggressive behaviors towards other shrimps and fish. If there isn’t enough food available, they may attack smaller species like cherry shrimps or fish fry. They are seen fighting and getting violent over food so it’s something you will want to keep an eye on. 

To keep your aquarium algae-free, it’s best to have a group of Amano Shrimps but make sure you are keeping them well fed so they don’t pick fights. Since these shrimp are larger than average, they will need more food.

If you have the bad habit of feeding your fish more than what they eat then you might not need to feed your Amano Shrimps separately as they will eat the remaining leftovers. But if you have a shrimp-only tank or feed your fish only what they eat then you should definitely feed them on time so they don’t get aggressive. At the same time if you have enough algae available in the tank for them to eat you might not need to feed them separately.

Amano Shrimp Care

Amano shrimp care is easy as long as you provide them with the right conditions. These shrimps need a clean tank that is mature and well-aged. A mature tank will not only have stable water parameters but will also provide your shrimps with natural food sources. 

These shrimps are low-maintenance that will happily live with other species in a community tank. However, like most shrimps, Amano shrimps do not appreciate fluctuation in the water parameters. 

Having stable water conditions with so few fluctuations is crucial for keeping Amano’s long term. These shrimps will need specific water conditions to thrive and as long as your tank’s water parameters fall within their optimal range, they will flourish.

Tank Size

Amano Shrimps can live in an aquarium as small as 5 gallons. But you will have to follow the basic rule of one shrimp per gallon. So in a 5-gallon tank, you can only keep 5 Amano shrimps and no other living creatures. 

However, these shrimps will thrive in large aquariums that provide them with more surfaces to explore. Like most shrimps, the Amanos love to walk more than swim so having more surface will keep them happy. There are multiple ways to extend the available surface in your aquarium which we will discuss below in the tank setup section. 

Tank Setup:

As mentioned, Amano shrimps love to have a lot of surfaces in their tanks. This is because they can find more algae and biofilm. Creating more surfaces than what your aquarium already has is easy and simple. All you have to do is to add more decorations and live plants to your tank. Decorations and live plants will bring in a more walkable surface for your Amano shrimps and at the same time more surface to grow algae. This is very important as Amanos eat algae as their main source of food. 

You can create beautiful scenes by placing different types of plants and making your tank look exactly the way you want it to look. Amano shrimps are not picky on the choice of plants you would want to go with and will happily accept all plants. However, our favorite choice of plants for them are Subwassertang, Java Moss, and Christmas Moss. These plants do not have roots and will extract ammonia and waste from the water column. They also don’t need intense lighting which makes them a great choice for any shrimp tank. 

Driftwood is also another important element to add to your tank but make sure they are well aged and not releasing a lot of tannins in the water. Well-aged driftwood will provide natural food for your shrimp as well as keep your tank more beautiful. That said, Amano shrimps like to live in neutral to slightly high pH levels. Having driftwood that releases a lot of tannins will lower the pH in the tank and thus not be healthy for the shrimps. 

For shrimps, sand is the best choice of substrate. This is because the food can not sink into the substrate and rot. The only downside to sand is that if food can somehow make its way into the sand, it will cause air pockets containing ammonia which is lethal for shrimps. To prevent air pockets, every time you are changing water simply move the sand around to make sure no air pocket is in the sand. 

These shrimps are also known to jump out of the water so it is important to have a lid for your tank. This is especially important when you first bring them home. The changes in the water parameters will stress them out and make them jump out of the water. 

Water Parameters

In the wild, Amano Shrimp live in super clean waterways that are oxygen-rich. The water moves slowly and has lots of algae grown everywhere. Recreating similar environments in your tank will make sure your Amano shrimps will experience their best life with you. 

These shrimps like to live in warmer waters but need a lot of oxygen that a warmer tank might lack. So you will have to have an air bubbler in your tank to make sure your shrimps get the ideal water parameters. That said, below are the best range of parameters to keep your Amano Shrimp in: 

• Temperature: 72 – 78 Degrees Fahrenheit 
• PH: 7.0 – 7.5
• TDS: 60 – 150 PPM

As mentioned above, it is important to have an air bubbler in the tank to make sure your tank’s oxygen levels stay high when the temperature is at 78 degrees Fahrenheit. An air bubbler will cause the water to move and creates surface agitation that helps with gas exchange in the tank.

Lighting:

Amano Shrimps are semi-transparent shrimps that appreciate shades. While they can tolerate intense lighting for a short amount of time, they will show signs of stress when light is too intense for too long. 

Having a lot of plants and decorations will give your shrimps enough shade and hiding areas that you can enjoy a brighter light in your tank. At the same time having plants means you have to use a strong light so they can grow. Keeping plants will make your tank more pleasant for you and the Amano shrimps even when the lights are strong. 

Filtration System:

Due to the sensitive nature of Amano shrimps, it is important to invest in the right type of filtration. These shrimps come from pristine water parameters in their natural habitat so it is important to keep your tank in pristine conditions as well. 

They do not like quick changes in the water parameters and will jump out of the water when the water is not clean. By having a filter that can manage the bioload in your tank, you provide your shrimp with a steady environment that they can call home.

Our top choice of filter for any shrimp tank is a simple sponge filter. It is the ideal solution for filtrating shrimp tanks since it creates a steady current in the tank while aerating the water. Another perk of sponge filters is that they won’t suck in shrimps like other types of filters.

Hang-on-back and canister filters are also good filters but they might suck the shrimps in. For this reason, we suggest sticking to the sponge filters.

Common Diseases and Prevention

Amano shrimp are hardy species that will not get sick very easily. Most diseases they encounter are because of poor water conditions in the tank. When water is not clean your shrimps will develop all sorts of bacterial and fungal infections. They will be at risk of getting internal or external worms as well. 

To keep your shrimps healthy you will need to have your tank in pristine condition at all times. By keeping your tank clean you are removing the causes of infections in your Amano shrimps tank. So we highly recommend doing regular but small water changes as well as feeding just enough that your shrimps and fish can eat in a short amount of time.  

Amano shrimps are highly sensitive to copper so it is important to make sure no copper can make its way to your aquarium. Even small amounts of copper will cause the hemocyanin in their blood to break down and cause immediate death. While most decorations and fish foods are copper-free, some aquarium medications have traces of copper. If you need to medicate your fish, make sure to check for copper. 

Diet and Feeding Requirements

Amano Shrimp eat almost anything organic but their main source of food in nature is algae. Shrimps are evolved to be the cleaning crew of nature so they feed on anything that is edible. Their first choice of food is algae and decaying plant matter but they will happily eat high-protein foods as well.

Your aquarium will naturally provide them with some algae to eat but you will have to feed them as well. Any plant-based food that has high amounts of algae will do the trick. Ideally, you will want to mix different types of sinking foods with some flakes and feed them to your Amano shrimps. Fish Flakes are not an ideal choice of food as they don’t sink so your shrimps might not get the chance to eat them before they reach the filter. 

Calcium for Amano Shrimps

Amano shrimps need calcium in their diet so they can grow new shells. Depending on the temperature, they usually mold once a month. This means they need a lot of calcium in their diet to be able to build a new shell quickly. 

Fortunately, it is easy to provide them with the calcium they need. You can use commercially made calcium supplements or cheaper alternatives like cuttlebone or even free egg shells. If you decide to go the budget route, you can place a cuttlebone in the tank for them to eat or powder the eggshells and add them to your tank. Egg shells are almost 100 percent made of calcium and are a great source of calcium for your Amano shrimps.

Gender Differences

Identifying Amano Shrimp’s gender is very easy and simple. Like all shrimps, female Amanos are usually bigger and bolder in comparison to males. But the main difference is in their body pattern. 

Males usually have evenly placed dots on their sides whereas the females develop broken and uneven dashes. The female Amano shrimps also have a small saddle (patch) on the back of their heads. This is a patch created by the eggs being developed in the female’s body. 

Breeding

Breeding Amano shrimps is a little tricky but definitely possible. These shrimps will mate in freshwater but the fry needs to be in brackish water to be able to survive. When you create the environment they need and feed them enough, these shrimps will rapidly breed.

To breed Amano shrimps simply put around 10 – 15 shrimps in a shrimp-only tank and raise the temperature slightly. The females will soon release pheromone letting the males know that they are ready to breed. Once mating is done you will find your female Amano carrying many eggs under her belly. The eggs can take up to 5 weeks to hatch. 

Right before the eggs are about to hatch you will need to move the female to another tank. The new tank should have the same water conditions as the main tank but you will have to slowly add salt to make it brackish. This process should be done very slowly and over days to avoid any stress to the female. The salinity of the water depends on the hardness of your water and the strain of the Amano shrimp you are keeping, but usually around 15 – 30 ppt.

Once the eggs are hatched you must remove the female so she doesn’t eat the newly hatched larva. You can keep the larva in the brackish water for another 4 – 8 weeks before slowly lowering the salt content to 5 ppt or normal freshwater. You must start lowering the salinity right around the time the larva stage is ending or they will not survive.

As you see this is a very frustrating and delicate process to breed these shrimps and many things can go wrong. This is why not many people try to breed Amano shrimp in captivity. You will need to try and find the right numbers and time frames for your strain of shrimps and water parameters for your breeding project to work.

Tank Mates

Amano Shrimps are slightly big shrimps and can defend themselves against peaceful fish. However most aggressive fish or any fish that has a large mouth might find them a great snack. So it’s important to keep them in a tank with peaceful fish. 

Here are our top tank mates for Amano Shrimps:

• Mystery Snail
• Guppies
• Neocaridina Shrimps
• Caridina Shrimps
• Plecos
• Mollies
• Apple Snail
• Ramshorn Snail
• Nerite Snail
• Otocinclus 

Conclusion

The Amano Shrimps or Yamato shrimps are great algae eaters belonging to the caridina shrimps. They are semi-transparent shrimps with the ability to devour different types of algae. While these shrimps are hardy, they are not beginner-level shrimps so only try to keep them if you have some experience keeping shrimps. However, by following the information we provided you in this guide, you should be able to confidently keep them in your tank. If you have any questions you can always reach out to us via email or on our Instagram page.