Say hello to a long-time aquascaper favourite! With their exceptional cleaning skills, peaceful nature and interesting appearance, Amano shrimp make a great addition to the peaceful tropical community tank.
Keep reading for everything you need to know about Amano shrimp care and keeping Amano shrimp in your own aquarium.
|Minimum tank size||10 gal (38 L)|
|Temperature||68-86 °F/20-30 °C|
Caridina multidentata (or formerly known as Caridina japonica) is commonly called Amano shrimp, Japonica shrimp, or Yamato shrimp. They are also generally categorized into freshwater algae eating shrimp and dwarf shrimp.
Adult Amano shrimp are found in Taiwan, Korea, and the Yamato freshwater river areas throughout Japan where plants and algae are bountiful and the sediment is soft. Amano shrimp will move to brackish water or saltwater areas during breeding periods. Because the larvae need this saltier water to survive the first few stages of life, the majority of Amano shrimp present in hobby aquariums is wild caught. They have been known to live for 2-3 years on average.
Amano shrimp are some of the largest dwarf shrimp, growing up to about 5 cm (2 inches) and making them easily distinguishable from smaller bee shrimp and red cherry shrimp. They can easily be recognized by their greyish transparent bodies with rows of dots on each side. The coloring and size of these dots can vary with diet, ranging from reds and browns to blues and greys; most plant and algae eating Amano shrimp will have hints of green that help them blend into the foliage.
These dots are also used to help identify the males from the females. Female Amano shrimp are typically larger and have a bottom row of longer dashes instead of short dots. Females also carry small eggs in the saddle section of their abdomens and can be seen waving water over the nest to supply oxygen.
We will further discuss breeding and mating behaviors later in the article, as well as the difficulties of raising Amano fry in an aquarium setting.
Amano shrimp requirements
Part of what makes Amano shrimp such a great addition to your aquarium is that they don’t demand very specific water parameters or temperatures. As hardy shrimp, they will thrive in any freshwater tank that is well established with plants and algae.
How many shrimp can you have per gallon?
Amano shrimp are best kept in 10+ gallon (35+L) cycled tanks. They should be in groups of odd numbers with a high female to male ratio to prevent any issues with dominance. In general, one Amano shrimp should be added for every two gallons of water, but increased bioload should always be considered per system.
They may be kept with other community fish, shrimp, or in a single species tank. Since freshwater shrimp are prey and go through molting periods, live plants and shrimp tubes should be added for hiding. Plants like java moss and green caboma provide excellent coverage and make for a natural aquarium.
Amano shrimp do not require any special nutrients or dosing supplements, but traces of copper in the water will cause the shrimp to die along with any other susceptible fish or invertebrate.
Strange but true: the more hiding places you provide, the more you’ll see your Amano shrimp. They’ll feel safer and more confident venturing into open spaces if they know they can retreat to a hide quickly.
What can be kept with Amano shrimp?
Before purchasing Amano shrimp, make sure you know if the fish in your tank have an appetite for seafood! It would be a shame to have your new additions end up as dinner on the first day.
Amano shrimp can live in any freshwater community aquarium as long as the size of their tankmates’ mouths is smaller than the size of the individual shrimp. They will be unbothered by snails, but should not be put in with crayfish or larger invertebrates; if you think your shrimp could become a fast meal, it probably will be. Smaller carnivorous fish like dwarf cichlids, Bettas and killifish might work, but anything bigger than these can prove to be risky.
Amano shrimp (Caridina multidentata/Caridina japonica) may also be housed with other algae eating shrimp as well, such as ghost shrimp (Palaemonetes paludosus), red cherry shrimp (Neocaridina davidi), or bee shrimp (Caridina cantonensis), as long as an ample food supply is provided. They can also bring life and excitement to a single species planted tank without any other fish.
Amano shrimp diet
Although Amano shrimp are commonly appreciated for their algae eating capabilities, you shouldn’t forget to supplement their diet, especially when algae and detritus levels are low. Our aquariums are usually just not ‘dirty’ enough to sustain a group of shrimp, which can leave them hungry. This can cause fatalities when it’s time for the shrimp to molt because a new exoskeleton requires a lot of calcium and other nutrients to develop successfully. Amano shrimp are omnivores, so they’ll accept pretty much any kind of food.
- Specialized shrimp foods are preferred. I tested the GlasGarten brand shrimp food with my Amano shrimp and they seemed to love it, so if you’re looking for a staple food it might be a good option. You can find my review here.
- For some great extra variety in their diet, you can feed your Amanos blanched vegetables like cucumber and zucchini.
- Frozen foods, such as mosquito larvae, blood worms, and brine shrimp, shouldn’t make up the bulk of the shrimps’ diet but can be fed occasionally to provide extra nutrients.
- Regular tropical fish food will happily be eaten as well.
Even if you’re relying on your Amano shrimp to clean up after their tankmates, don’t forget to manually remove any remaining leftovers within 3-4 hours to keep the water clean. Rotting foods can cause serious water quality issues!
Their diet is what made these shrimp famous. They first became popularized in the 1980s after Takasi Amano, a famous Japanese aquarist, discovered that Amano shrimp are super effective algae eaters. They have since become a staple clean-up crew member to the freshwater aquarium hobby.
Amano shrimp will typically eat anything that is put in front of them as they are scavengers. Because they are larger than most other shrimp, they will be the first to grab at any flakes or sinking pellets. It is important to keep in mind that all other shrimps and smaller invertebrates will most likely end up with what your Amanos haven’t finished.
Despite their voracious appetites, Amano shrimp are known to be picky; they will likely eat anything and everything else before resorting to your nuisance algae. In order to pique your shrimp’s interest in the detritus in your tank, make outside food less readily available. This will cause your shrimps to graze on any problem areas, but make sure to supplement once those areas have been cleaned.
Amano shrimp are still some of the handiest clean-up crew members to have in your tank because they’re one of the few known shrimp that will eat black beard algae and green hair algae, placing them on the best aquarium algae eaters list. Always remember to monitor how many outside nutrients you are inputting into your fish tank and how they are being used and cycled by its inhabitants!
Amano shrimp behavior
Apart from being slightly greedy during feeding time, these shrimp are very peaceful and fun to watch as they create extra movement in a stagnant tank.
They spend most of their time foraging for leftover bits of food in a group but also swim around occasionally, especially after water changes and during mating periods. If an Amano shrimp has just molted, it may disappear from the front of the tank so that it can regrow its exoskeleton without being eaten. During mating periods, which usually occur after a female’s molt, Amano shrimp will exhibit a sort of ‘dance.’ At this time, females may be chased around the tank in efforts made by the male to mate.
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About every month and a half, freshwater shrimp will go through a molting period in order to grow. Don’t be alarmed! It is very easy to mistake an empty shell for a dead shrimp when first looking into your tank. If you can’t tell if your shrimp has molted, allow a few hours to go by. Amano shrimps will hide after molts as this is when they are most vulnerable, so keep your eye out for if yours reappears during this time.
If there are no signs at all of your shrimp after a few hours, remove the shell so ammonia doesn’t begin to seep into the aquarium in case it wasn’t a molt. Once taken outside of the tank, it will be clear if your Amano shrimp has molted or not. If it wasn’t a molt, you should test your water parameters to make sure that the tank is still stable.
Breeding Amano shrimp
In the aquarium trade, Amano shrimp are often wild caught because of how difficult they are to breed. More specifically, the problem is not so much that they’re hard to breed, but rather, actually keeping the fry alive. You’ll often see females carrying eggs, but hatching and raising the young is the hard part.
Unlike most dwarf shrimp species, which hatch as tiny copies of their parents, Amano shrimp start their lives as larvae that require brackish or saltwater. After their larval stage, they need to be transferred back to freshwater. In a normal freshwater aquarium the larvae often simply end up as food for the other fish or die shortly after hatching.
This means you’ll often see your female Amanos carrying eggs between their swimmerettes (back legs) and being chased by the males, but never any fry. It’s pretty difficult to breed Amano shrimp, but a few experienced aquarists have reported success.
If you’d like to try your hand at breeding Amano shrimp, consider checking out the article on Amanos that I wrote for Aquarium Hobbyist Magazine a while back. It contains more info about the process of rearing the fry. Challenging, but not impossible – it has been done! You can find the article here (Q1 2018, p. 10-12).
Buying Amano shrimp
Because most Amano shrimp are wild caught, they tend to be more expensive than other similar shrimp. If you’re looking to buy Amano shrimp be sure to look for ones that appear healthy and are actively foraging and moving around. The size of each shrimp should be considered given the fish and other invertebrates already in your tank. Amanos with a milky-colored body and shrimp that sit motionlessly might not make it, so you’re best off avoiding those.
You can buy Amano shrimp online here!