Amano shrimp care is what you research the first time hair algae takes over a planted tank and nothing you’ve tried has worked: less light, more water changes, Excel by the capful, and the algae just keeps coming back. Takashi Amano figured this out in the 1980s, named the species after himself (not quite, but practically), and planted shrimp colonies in his Nature Aquarium tanks specifically because Caridina multidentata does something no other common aquarium species does as well: it eats hair algae. Not just grazes past it. Actually eats it, strand by strand, all day long.
That’s the reason to get amano shrimp. They’re not colorful. They won’t breed in your tank. A colony of six will slowly shrink to zero over two to three years, and you’ll need to replace them. None of that disqualifies them. They’re the algae-control workhorse of the planted tank hobby, and when the conditions are right, they genuinely earn their keep.
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Amano shrimp care at a glance
| Attribute | Detail |
|---|---|
| Common Names | Amano Shrimp, Yamato Shrimp, Japonica Shrimp, Algae-Eating Shrimp, Japanese Swamp Shrimp |
| Scientific Name | Caridina multidentata (formerly C. japonica) |
| Family | Atyidae |
| Origin | Japan, Korea, Taiwan (wild-collected; most in trade are not captive-bred) |
| Adult Size | Up to 2 in (5 cm); females typically larger than males |
| Lifespan | 2–3 years in captivity |
| Tank Size | 10 gallon minimum for a group of 3–5 |
| Temperature | 65–80 °F (18–27 °C) |
| pH | 6.5–7.5 |
| Temperament | Peaceful; active scavengers; will not bother tankmates |
| Diet | Omnivore; algae specialist (hair algae, biofilm, soft green algae, diatoms) |
| Care Level | Easy |
What amano shrimp look like (and how to spot a real one)
Amanos are translucent grey-green with a distinctive pattern of horizontal dashed lines running along each flank. Those dashes are the diagnostic feature. Every other similarly sized shrimp in the trade has dots, spots, or solid bands. If the shrimp has clean, continuous dashed lines along the sides, it’s an amano. If not, look more carefully at what you’re buying.
Sexing them is straightforward once you know what to look for. Females are noticeably larger and deeper-bodied, with a curved lower profile and a visible saddle (egg mass) under the abdomen when ripe. Males are slimmer and more torpedo-shaped. A healthy breeding-condition female will carry a dense cluster of tiny dark green eggs under her tail for several weeks.
The truth about amano shrimp lifespan (and why your colony shrinks)
Amanos live 2–3 years in a well-maintained tank. That’s not a long time, and it leads to a predictable frustration: you buy six shrimp, they settle in, they work great for a year, and then you start finding empty shells. Within 18 months you’re down to two. By month 30, they’re gone.
This is biology, not failure. Amanos don’t reproduce in freshwater (more on that in the breeding section), so your colony doesn’t replenish itself. Every shrimp you lose is a permanent reduction. Plan on replacing the group every two to three years if you want consistent algae control.
The “my amanos keep disappearing” panic is also common. Amanos molt regularly, and a freshly molted shrimp will hide for one to three days while its new shell hardens. During that window it looks like your shrimp has vanished. Leave the shed exoskeleton in the tank. The shrimp will often eat it for the calcium, and pulling it out removes a mineral resource they need.
Amano shrimp tank size and setup requirements
Ten gallons is the practical minimum for a group of three to five amanos. If you want serious algae control in a planted tank, six to ten shrimp in a 20-gallon long is the better target. A longer footprint gives them more grazing surface and more biofilm to work through between supplementary feedings.
Unlike crystal red or Taiwan bee shrimp, amanos don’t require active aquasoil. Any substrate works. Sand and fine gravel are my preference because they’re easy to clean and don’t affect water chemistry, but bare-bottom tanks are fine too. If you’re running a planted tank for algae-control purposes, you probably already have substrate sorted.
For hardscape, prioritize surface area and biofilm. Cholla wood and Spider wood are excellent: porous, irregularly shaped, and they host the biofilm layer that amanos graze between meals. Indian almond leaves (Catappa) break down slowly and add tannins and biofilm; drop a fresh leaf in every few weeks as the old one decomposes. Java moss anchored to driftwood gives them both cover and grazing material.
For a full walkthrough of shrimp tank layout and equipment, the complete shrimp tank setup guide covers substrate selection, planting, and cycling in detail.
Filtration and intake safety
Amanos are big enough that a standard HOB or canister filter intake won’t kill them the way it kills cherry shrimp juveniles. That said, a pre-filter sponge over any HOB or canister intake is still worth adding. It protects the shrimp from getting wedged against the intake during molts when they’re soft and slow-moving, and it grows additional biofilm for them to graze. A dual-sponge filter running as your primary or secondary filter is even better since it provides both biological filtration and a zero-suction environment.
Let the tank run for four to six weeks before adding amanos. They’re not as sensitive as crystal red shrimp, but they still need a cycled tank with an established biofilm layer. An uncycled tank with no biofilm gives them nothing to graze while they’re adjusting.
Amano shrimp water parameters: temperature, pH, and hardness
This is where amanos stand apart from the rest of the Caridina genus. Crystal red shrimp and Taiwan bee shrimp need pH 5.8–6.8, KH near zero, and RO/DI water remineralized to exact targets. Amanos tolerate the kind of water that comes out of most municipal taps without modification.
| Parameter | Target Range |
|---|---|
| Temperature | 65–80 °F (18–27 °C) |
| pH | 6.5–7.5 |
| GH | 6–15 dGH |
| KH | 2–8 dKH |
| TDS | 150–300 ppm |
| Ammonia / Nitrite | 0 ppm (both) |
| Nitrate | Under 20 ppm |
The cold-tolerance is one of amanos’ underrated advantages. At 65 °F they’re active and healthy, which means they work in unheated tanks during temperate summers without a heater at all. Standard community tanks running 74–78 °F are perfect. They’re not happy above 80 °F for extended periods, so if your tank runs warm in summer, a small fan or chiller is worth considering.
Pick up an API GH and KH test kit if you haven’t tested your tap water. Most US municipal supplies land in the 6–12 dGH, 4–8 dKH range that works fine for amanos without any adjustment. Dechlorinate with Seachem Prime on every water change.
What do amano shrimp eat?
Amanos eat hair algae. That’s the headline. But there are honest limits to what they’ll tackle, and overfeeding them is the fastest way to make them stop being useful.
They’ll graze hair algae, thread algae, soft green film algae, diatoms (the brown dust that coats new tanks), and decomposing plant matter all day without prompting. They’re opportunistic and constant: always picking, always working across hardscape and leaves. A group of six in a 20-gallon planted tank with a moderate hair algae problem can clear it in one to two weeks.
Where they fall short: black beard algae (they’ll pick at dead BBA after you’ve hit it with hydrogen peroxide or Excel, but healthy BBA attached to surfaces is largely ignored), green spot algae on glass (they can graze it from plants and rocks but lack the rasping mouthparts to scrape it off smooth glass; nerite snails are the better tool for glass GSA), and cyanobacteria. If you’re dealing with BBA, glass GSA, or cyano, amanos aren’t a complete fix on their own.
| Food | Type | Notes |
|---|---|---|
| Hair algae and thread algae | Primary diet | What they’re in your tank to eat; don’t overfeed or they ignore it |
| Biofilm and diatoms | Primary diet | Grazed constantly from wood, rock, and glass surfaces |
| Hikari Crab Cuisine | Supplementary sinking pellet | 2–3× weekly; use a feeding dish to prevent uneaten pellets fouling substrate |
| Hikari Algae Wafers | Supplementary sinking wafer | Break into small pieces; shared with corydoras and otocinclus in community tanks |
| Bacter AE | Biofilm supplement | Cultivates bacterial biofilm on surfaces; excellent for establishing new tanks or boosting biofilm between feedings |
| Blanched zucchini or spinach | Vegetable supplement | Remove after 24 hours; occasional treat rather than staple |
| Decomposing Indian almond leaves | Natural supplement | Add one leaf every few weeks; breaks down slowly and hosts biofilm |
The critical feeding rule: if your amanos are eating sinking pellets eagerly, they’re not hungry for algae. Feed supplementary foods only two to three times a week, and only a small amount. A stainless steel feeding dish keeps pellets contained so they don’t dissolve into the substrate and spike ammonia. Well-fed amanos are lazy algae grazers. Slightly hungry amanos are machines.
Best amano shrimp tank mates (and what to avoid)
Amanos handle community tanks better than cherry shrimp for two reasons: they’re bigger and less colorful. A 2-inch translucent shrimp is less visually interesting to a fish than a bright red cherry shrimp. They’re also fast enough to escape most non-specialized predators. That said, any fish with a mouth big enough to fit them will try eventually.
| Species | Compatibility | Notes |
|---|---|---|
| Neon and cardinal tetras | Good | Too small to threaten adults; classic planted-tank pairing |
| Harlequin and lambchop rasboras | Good | Peaceful schooling fish; widely recommended community pairing |
| Corydoras catfish | Good | Bottom dwellers; compete for sinking pellets but don’t bother shrimp |
| Otocinclus catfish | Good | Fellow algae workers; peaceful, complement amanos well |
| Nerite and mystery snails | Good | No conflict; mystery snails reproduce, so check our snail reproduction guide if you want to control population |
| Cherry shrimp | Good | Different species; no interbreeding, no competition issues; populations stay separate |
| Bettas | Caution | Individual-dependent; some bettas ignore amanos, others hunt them. Read our bettas and shrimp compatibility guide before attempting |
| Dwarf gouramis | Caution | Generally peaceful but large enough to eat shrimp; monitor closely |
| Large cichlids | Avoid | Will eat amanos; no exceptions for aggressive species |
| Pea puffers | Avoid | Specialized invertebrate hunters; will systematically target and kill shrimp |
| Loaches (clown, yo-yo, chain) | Avoid | Invertebrate predators; will hunt shrimp regardless of size |
| Crayfish | Avoid | Will catch and eat amanos, especially during molts when shrimp are soft |
Common amano shrimp health problems and how to handle them
Amanos are hardier than most shrimp, but they have the same critical vulnerability as every invertebrate in the hobby: copper is lethal to them at concentrations that don’t harm fish.
| Condition | Symptoms | Treatment |
|---|---|---|
| Molting failure | Shrimp stuck in old shell; lethargic; death during molt | Check GH (calcium deficiency is common cause); test with API GH kit; target 6–15 dGH; leave exoskeletons in tank |
| Copper poisoning | Sudden death; erratic swimming before death; entire group affected simultaneously | Remove survivors immediately to copper-free water; check any medication recently added to display tank; copper persists in substrate for months — a previously medicated tank may require full substrate replacement before shrimp are safe |
| Pesticide poisoning from plants | Sudden death shortly after new plants added; shrimp behave normally then die quickly | Quarantine all new plants in a separate container for 1–2 weeks before adding to shrimp tank; rinse thoroughly; prefer tissue-culture plants for shrimp tanks |
| Bacterial infection | Opaque white patches on body; lethargy; unusual coloration | Remove affected individuals; improve water quality and circulation; most shrimp-safe medications have limited efficacy — prevention via good water quality is the only reliable approach |
| Ellobiopsidae (green fungus) | Green growth visible on underbelly or legs, especially on females near egg-carrying area | Remove infected shrimp; parasite spreads to others; no reliable in-tank treatment; prevent via quarantine of new shrimp |
Why you can’t breed amano shrimp at home (the brackish requirement)
This is the fact most care guides bury or skip entirely. Caridina multidentata females carry eggs under the abdomen for roughly four to five weeks (longer at cooler temperatures, shorter at warmer ones), which looks exactly like cherry shrimp carrying eggs. The difference is what happens when those eggs hatch.
Amano larvae hatch as zoea: tiny planktonic creatures that require brackish water with a specific gravity around 1.005–1.015 to develop. In pure freshwater, the zoea die within days. Your community tank, your planted tank, your shrimp-only tank: none of these work. The larvae need marine salt, microalgae to eat (baby brine shrimp and cultivated phytoplankton), and a carefully managed salinity ramp-up over four to six weeks as they go through multiple larval stages before metamorphosing into juvenile shrimp. It’s a dedicated project that requires a separate brackish larval tank, cultures, and time.
A small number of dedicated hobbyists have pulled it off and documented the process. But for most planted-tank keepers, amano breeding is firmly out of scope. You will see females with eggs. Those eggs will hatch. The larvae will die. This is not a water quality problem. It’s the biology of the species.
The practical consequence: most amanos sold in the hobby are still wild-collected from East Asian streams. Your group will live two to three years and not be replaced by offspring. Budget accordingly and buy healthy specimens from reputable sources.
If you want a shrimp that breeds easily and builds a colony on its own, cherry shrimp are what you’re looking for. Our guide to breeding freshwater dwarf shrimp covers cherry shrimp and other Neocaridina species that reproduce in standard freshwater tanks without any intervention.
Amano shrimp care FAQs
How many amano shrimp should I get?
A minimum of five to six for any meaningful algae control. The common recommendation is roughly one amano per two gallons in a planted tank, but the more useful frame is: how much hair algae do you have? Serious infestations need ten or more. A small preventive crew for a 20-gallon planted tank is six to eight.
Do amano shrimp eat fish food?
Yes, enthusiastically. They’ll race across the tank for any sinking pellet or flake that hits the bottom. This is the trap: well-fed amanos stop working as hard on algae. If you notice your shrimp spending more time competing for fish food than grazing surfaces, cut back supplementary feeding. Their job is the algae.
Why is my amano shrimp turning white or transparent?
Increased transparency just before a molt is completely normal. The shrimp will hide for one to three days while the new shell hardens. If the shrimp appears milky white rather than clear and is behaving oddly (spinning, erratic movement, staying at the surface), that’s a different problem: bacterial infection, copper exposure, or a parasite. A shrimp that was previously active and is now white and stationary at the bottom is more concerning than one that’s simply gone translucent and hiding.
Can amano shrimp live with cherry shrimp?
Yes. They’re different species with no interbreeding risk. Cherry shrimp are Neocaridina davidi; amanos are Caridina multidentata. They occupy slightly different niches in the tank (cherries graze plant surfaces and biofilm; amanos tackle hair algae and heavier algae loads), and they don’t compete aggressively. The only management note: cherry shrimp will breed prolifically and amanos won’t, so your amano population slowly shrinks while cherries multiply.
How long does it take amano shrimp to molt, and what should I do?
The actual molt takes minutes. The hiding and shell-hardening period afterward is one to three days. Leave the exoskeleton in the tank. The shrimp (and sometimes other shrimp in the tank) will eat it for the calcium. Removing it wastes a mineral resource and gives you nothing in return.
Is an amano shrimp right for your tank?
The quick decision: if you have a planted community tank with hair algae and peaceful fish, amanos are the right call. A group of six in a mature 20-gallon planted tank with neon tetras, corydoras, and otocinclus is about as close to a self-cleaning ecosystem as most people get without CO2 injection and daily maintenance.
If you have a nano tank under 10 gallons, consider cherry shrimp instead. They’re smaller, they breed on their own so you always have a colony, and they don’t need as much algae to sustain themselves in a small tank.
If your goal is breeding shrimp and watching a colony grow, amanos are the wrong species entirely. Get cherry shrimp or crystal reds. Amanos are workers, not pets. They don’t breed in your tank, they live two to three years, and they’ll leave a gap in your algae control when they’re gone. But while they’re there and conditions are right, no other commonly available species does what they do as consistently.
Set up the tank properly, dechlorinate with Prime, keep copper-based medications out of the system, don’t overfeed them, and a group of amanos will earn their spot in a planted community tank every time.
