Originally known as Caridina japonica, and now Caridina multidentata, the Amano shrimp makes a perfect companion for most tank dwellers.
They are very small, spineless, algae eating creatures, with a peaceful nature. Suitable for any home aquarium owner, including beginners, they make the perfect chum for anyone with a freshwater aquarium.
They were first reared in captivity by their namesake, Takashi Amano, an aquarium enthusiast from Japan. Little did he know, at the time, that his discovery in the 1980s would revolutionize fish-keeping. Since then, these little creatures have been used as cleaning tools for almost all fish enthusiasts.
Most aquarium lovers would purchase this docile creature for its tank-cleaning qualities. In fact, it will vacuum up almost anything, including algae, neglected fish food, decaying matter, and other tank residues. With its inquisitive nature and interesting habits, you’ll want to watch it all day!
As they are notoriously difficult to breed (although it is possible), they are less popular than the red cherry shrimp. However, being part of the dwarf shrimp family, they can reproduce with others from this group.
Their care is a very straightforward business, requiring minimal skill or experience. Due to their hardy nature and foraging expertise, they make an easygoing addition to your tank. They are in fact one of the most apt creatures for a learner.
Quick Overview and Statistics
Before purchasing an Amano shrimp, it’s important to know all the nitty-gritty details. Therefore, the table below is a treasure-trove of information to identify these small creatures.
|Common name(s):||Japonica Amano shrimp, Yamato Numa Ebi, Japanese swamp/marsh shrimp, Yamato shrimp, algae-eating Shrimp, Amamoto shrimp|
|Scientific Name(s):||Caridina multidentata|
|Adult Size:||Up to 2 inches|
|Color Form:||Mostly tan/brown, but can be transparent and grayish|
|Minimum Tank Size:||10 gallons|
|Typical Tank Setup:||Plenty of hiding places—for example, plants and rocks, and algae to snack on|
|Tank Level:||Bottom feeder, but explores all over the aquarium|
|Water Conditions:||Freshwater, 60-80° F, KH 3-10, pH 6.0-7.6|
|Tank mates / Compatibility:||A peaceful creature, with the ability to live alongside numerous creatures, as long as they won’t eat it. Mainly compatible with snails and other shrimps.
Originating from Japan, they became part of the everyday fish tank almost 30 years ago. After their introduction to home aquariums, they uplifted the fish-keeping business. Since then, the hobby of owning these little creatures has rapidly grown, and they are now pretty common.
Although they come mainly from Japan, they can also be found in the wild in places such as:
- The Ryukyu Islands, near the Philippine and the East China Sea
- Madagascar (perhaps, but unlikely)
The Amano shrimp is a winner for any tank, as it requires plenty of algae to quench its large appetite. After the cherry shrimp, it is the most popular addition to almost all household fish tanks. If purchased in larger numbers, your tank could remain almost completely clean!
What Does the Amano Shrimp Look Like?
These small creatures are almost entirely transparent, with a brown interior, which you can see through their skin. They are one of the largest dwarf shrimp species, and are spineless, with little legs and antennae. They only grow up to two inches long, so are one of the smallest creatures you’ll find in a domestic tank.
Their front legs are called pereiopods and are situated just underneath its head. It’s other legs, called swimmerets, are underneath the abdomen, which is made up of numerous skeletal sections.
On their head are their short and long antennae, used for sussing out their surroundings. They also have a uropod, which is their tail. This can be used to swim around, as they push the uropod backward and forward, to tread the water.
Along the side of their body, you’ll find a long reddish-brown or bluish-grey line of dots. The color of this line will depend on their diet. It can be used to determine their sex, as a female’s line of dots will be more broken up.
In the wild, the female will have a noticeably swollen dorsal fin, and will generally grow larger than the male. Thus, if your shrimp are all the same age, the bigger ones are most likely female. Females will also have a little saddle, or egg nest, underneath their stomach.
Generally, shrimps as a whole are very easy to identify. However, getting the correct gender is difficult, especially due to the minimal differences in their appearance. By going to a reliable pet store, rather than online, you’re more likely to get the correct shrimp.
What are Their Natural Behaviors?
These creatures have a very peaceful and calm nature but have been labeled as semi-aggressive when they see food. We’ve all been there when the waiter arrives with a plate of food, and everyone looks up, well that’s what these little guys do—except they chase after it as soon as it hits the tank floor!
They enjoy hiding in enclosed areas, including plants, rocks, and caves. Therefore, to keep them happy, having these sorts of spaces dotted around your tank is advised.
Every month or so, they will molt, or shed their exterior shell. This might leave them feeling a little vulnerable, so you may not see them for a little while. In this case, a heavily planted tank is probably your best bet, to make them feel safer.
What Are the Ideal Tank Requirements and Habitat?
These freshwater invertebrates can usually be found in Japanese rivers, on the waterbed. They are bottom-dwellers who scavenge around the rocks and sometimes use their tails to swim around. They prefer slow-moving waters, so remain in shielded areas, so they are not washed away.
Amano shrimp are very sensitive to changes in the environment, so keeping them happy is paramount. Below are some of the critical things to remember when housing these gentle creatures:
What Size Tank Do They Need? How Many Gallons of Water per Shrimp?
With a 10-gallon aquarium, five to six individuals is preferable. This way, you can allow them plenty of space to forage, without the risk of losing them in the shrubbery.
What Water Type and Temperature Do They Prefer?
Apart from the saline solution the growing fetuses need, adult individuals must reside in slow-moving freshwater (see more on that later in the section on breeding). If the adults are exposed to salt water, they can die, as they are very sensitive to changes.
Generally, a tank temperature of 60 to 80 degrees Fahrenheit is preferred, with KH between 3 and 10, and pH levels between 6.0 and 7.6. Any swift changes can really shock these little beings.
What is a Suitable Substrate?
Riverbeds in Japan usually have small rocks and pebbles lining the river floor. Therefore, by mimicking this, your shrimp will feel right at home.
What Filter Should You Use?
Naturally, these creatures would prefer slow-moving waters. Therefore, anything which really disrupts the water movement is not best for them.
Powerful filters can easily suck in these little shrimp. Hence, it’s best to use a less powerful filter. One with a filter guard is also advised, to keep them safe from harm.
Do they Have any Preferential Lighting Needs?
As they are easily shocked, keeping them in the dark for the first day or so is best. This way, they can get used to their new surroundings without a spotlight on them. Then, gradually increase the lighting to a daylight level.
What Plants Should You Decorate Their Tank With?
As expressed earlier, be sure to garnish your tank with multiple crevices and plants for your shrimp to hide in. Perhaps you could purchase some plastic rocks from the pet store, or even just use some small stones from your backyard. Moreover, you could buy some water plants, giving them more greenery to hide in (and eat!).
One great way to ensure an easy meal for them is adding moss balls or sponge filters to the tank. This will catch floating particles, like algae, more easily, ensuring a large meal is accessible.
How Many Amano Shrimp Can You Keep per Gallon?
Generally, per gallon, just one or two is ideal. Any more than this and they will not have enough free movement around the tank.
What Do They Like to Eat?
In general, these helpful little omnivores will eat almost anything. They will love to do nothing more than explore the tank and enjoy the food they find. Below are some of the main foods they will eat.
What Do They Eat in Their Natural Habitat?
In the wild, they will eat almost anything! This includes algae on the bottom of the tank and dead matter on the water floor. Don’t be surprised if they munch on dead fish in your tank, as the decaying matter is a delicacy to them.
Generally, they will not eat anything alive and prefer decaying matter. This makes Amano shrimp care and feeding very easy.
What Should You Feed Your Amano Shrimp in the Aquarium?
With a small number of Amano shrimp and lots of algae in your tank, they won’t need much to eat. In fact, they will eat any waste products, including dead skin cells from their mates! In general, they’re like cows and will graze all day on the bottom of the tank.
Nonetheless, don’t be fooled into thinking they will survive without additional food. Some foods you can provide for them include:
- High-quality pellets.
- Hikari algae wafers.
- Frozen bloodworms or brine shrimp.
Are There Human Foods They Can Eat?
They will eat almost anything, especially greens. Blanched zucchini or spinach are great human foods to expose them to—anything green will do perfectly.
Be sure not to leave the food in the water uneaten for over an hour or two, though. This may contaminate the water, and we already know how sensitive these shrimp can be to change.
How Often Should You Feed Them?
As we mentioned above, these grazing creatures will not need too much extra food. It will depend on the amount of shrimp you have, and the amount of algae available. Start by adding a few pieces of food to the tank and see what they make of it.
Usually, they will quickly get to the food before anyone else does, so you’ll know if they need more. If they fail to do this, add a few more pieces of food in for your shrimpy friends. If they don’t want the food, they will just ignore it, so don’t go overboard.
Are There any Special Care Requirements?
As most of these shrimp (97 percent) come straight from wild waters, correct care is essential for them to adapt properly. Indeed, they can be very sensitive to water quality and temperature. If you want to keep them alive for longer, keeping these elements adequate is imperative.
Acclimatizing your shrimp is the key to success. Some ways of doing this effectively are:
- Noting down the water values in the aquarium to match them in your own
- Leaving the lights off during the first 24 hours of gaining your new family members; they can shock very easily.
- Keeping a close eye on them during the first day or so, to note any changes in behavior.
- Checking that the ammonia and nitrate levels are low.
- Ensuring a small level of iodine is added to their water can also help them molt.
- Making sure to not add any copper-based substrates to the water, as this can kill them.
The most important element of looking after these creatures is simply ensuring to monitor their water. If it dips or rises beyond the recommended levels, removing them from the tank into a temporary water source is advised.
What Other Fish Can they Share their Tank With?
These friendly and curious shrimp are very peaceful, so will make a great companion for almost any tank mate. However, their small size means they might make the perfect lunch for some larger fish. It also means they don’t require such a large tank, so larger fish may be too big for their tank.
In light of this, it is best to put them in a smaller tank, with groups of other shrimp or snails. Also note that there are some types of dwarf shrimp which are only compatible to mate with certain other shrimp. Luckily, the Amano can mate with any other type, so this will not be a problem.
Generally, the Amano is particularly easy-going, so will not cause any issues with other fish. Some particularly great tank mates for them are cherry shrimp and mystery snails.
Can You Keep Many Amano Shrimp Together?
You can keep many of them together, as they are extremely friendly. On their own, they wouldn’t be of much use anyway regarding cleaning. For maximum tank-cleaning potential, it is actually recommended to purchase these creatures in large numbers!
A group of six is usually a good number to keep together. Also, an even number of males and females is advised. This way, dominant behavior will be minimized.
One issue to watch out for is that most fish are predators toward these small creatures. In fact, even adult dwarf shrimp can sometimes eat the smaller ones. Therefore, buying them at the same time, and at the same age, is advised, to establish a larger colony.
The Amano shrimp usually cost around $3 to $4, so will make an extremely cheap addition to your tank. You can buy them through your local pet store, or online via liveaquaria.com or ebay. They are such a popular addition to people’s tanks that they are not hard to come by.
Although, you can buy them online, they are easily shocked. Therefore, it might be best to venture to a physical pet store to purchase a few. This way, you can be sure of the care conditions your pet has received before rearing them in their new home.
Remember, bulk buying these little creatures is probably your best bet to keeping them happy. Indeed, they are not solitary creatures and will socialize and thrive in a pack.
Can You Breed Them at Home?
As expressed previously, Amano shrimp are extremely difficult to breed. However, it is possible, and it’s best to leave them to do so naturally at first. Just ensure to feed them well, and raise the tank temperature to around 78–80 degrees Fahrenheit.
The male will fertilize as many as 3000 eggs, carrying them for five to six weeks. Meanwhile, the female will waft oxygen over the eggs using her tail. Then, the adults drop the eggs into salt water, as this is needed for them to grow.
After this, however, they seem to struggle to raise their little one’s past larvae development. Therefore, this is where human intervention comes into play.
Firstly, keep an eye out to see if any of your males have eggs. After the six-week mark, they should be dropped into salt water, between 17ppt and 35ppt. Remember, though, the adult shrimp will die if they touch the salt water.
Remove the eggs from the saline water when they reach metamorphoses (30–60 days), and move the female back in with them. The female might try to eat her young once hatched, so remove her again in this case.
If you get to the stage where the little ones are thriving, feeding them brewers yeast is the way forward. For more information, this detailed guide for breeding shrimp is a good place to start.
Interesting Facts and Trivia
Now you know the hard facts about our friend, the Amano shrimp, here are some more interesting snippets of information:
- When a fish preys on an Amano shrimp, it will suck water rapidly through its mouth to pull it in. They will then use their entire abdomen to push itself away from this suction.
- Word on the street is that some “Amano shrimp” are imposters, and are only sold under that name. Indeed, it is easy to confuse different species, as they all look very similar.
- As we have seen, they are notoriously difficult to breed. Sometimes, breeders have even noted that they rarely mate at all.
- This creature is known as an arthropod, which means it is made up of multiple sections on its body.
- They use gills to breathe.
In general, these creatures are really easy to look after, so there are only a few main points to really remember for the best Amano shrimp care.
Firstly, acclimatizing the shrimp to the water is a tricky business and requires a fair bit of care and attention. They are also extremely difficult to breed, so it’s probably best to leave this to an expert.
Generally, just allowing them lots of areas to hide will create the perfect habitat for these inquisitive beings.
Overall, the peaceful Amano shrimp is perfect for any beginner, particularly one who may be a little lazy with their tank clean-up. If you have any questions or anything more to add, please leave us a comment down below—we’d love to hear from you!
Happy fish keeping!