Amano shrimp are the workhorses of the freshwater aquascape world. Named after Takashi Amano — the aquascaping pioneer who introduced them to the hobby — they’re 3–5cm shrimp with a specific superpower: they eat hair algae, staghorn algae, and biofilm in quantities no other shrimp matches.

If you have algae problems and don’t want to add fish, Amanos are the correct answer. Unlike cherry shrimp, they don’t breed uncontrollably in freshwater (a plus for controlled populations), and they’re much larger and hardier once established.

Quick facts

• Scientific name: Caridina multidentata (formerly C. japonica)
• Common names: Amano shrimp, Yamato shrimp, algae shrimp
• Origin: Japan and Taiwan freshwater streams (adults freshwater, larvae need brackish)
• Adult size: 3–5 cm (larger than cherry shrimp)
• Lifespan: 2–3 years typical
• Water temperature: 18–28°C (huge tolerance)
• pH: 6.5–8.0
• Water hardness: soft to medium (5–15 dGH)
• Minimum tank size: 40L for a group of 5
• Social: peaceful, non-aggressive; keep in groups of 5+

What makes them different from cherry shrimp

If you’ve read our cherry shrimp guide, the key differences:

Feature	Cherry shrimp	Amano shrimp
Adult size	2.5–3.5 cm	3–5 cm
Colour	Vivid red (or other colours)	Translucent grey-brown, spotted
Breeding	Prolific in freshwater	Cannot breed in freshwater (needs brackish larvae)
Algae type	Biofilm, soft green	Biofilm PLUS hair, staghorn, string algae
Price (UK)	£2–£8 each	£3–£8 each
Lifespan	12–18 months	2–3 years
Coldwater tolerance	Fine down to 18°C	Fine down to 15°C

Choose Amano over cherry if: You want algae eaters that don’t breed, need to control hair algae, or want a longer-lived shrimp.

Choose cherry over Amano if: You want vivid colour, want a self-sustaining colony, or specifically want to try shrimp breeding.

Many aquarists keep both — cherries for colour and breeding, Amanos for algae control.

Tank setup

Tank size

• Minimum: 40L for 5 Amanos
• Better: 60L+ for a group of 8–10
• Bigger is easier — Amanos need swimming space and produce moderate waste

Filtration

Same as cherry shrimp — sponge filter with air pump is ideal (safe for babies… though babies won’t survive freshwater anyway). For canister or internal filters, use a sponge pre-filter.

Plants and hardscape

Non-negotiable for shrimp tanks. Amanos graze on biofilm continuously.

• Java moss — grazing surface
• Cholla wood — biofilm generator
• Anubias or Java fern — attached to wood, provide cover
• Indian almond leaves — mildly buffer pH, feed biofilm

Water chemistry

Cycle the tank first — see our UK cycling guide.

• Ammonia / Nitrite: 0 (always) — Amanos are very sensitive
• Nitrate: under 20 ppm
• pH: 7.0–7.8, stable
• GH: 6–15 dGH (calcium for moulting)
• KH: 3–8
• Temperature: 22–26°C

Amanos tolerate the widest range of parameters of any freshwater shrimp. Adjust if you’re keeping them alongside specific species requiring soft/hard water.

No copper — copper medications kill shrimp within hours. Always check labels.

Feeding

Amanos are famously algae-eating but need supplemental food in cleaner tanks.

In an algae-heavy tank: they can feed themselves for weeks.

In a well-maintained tank:

• Hikari Shrimp Cuisine — 1 pellet per 5 shrimp, 2× weekly
• Blanched vegetables — courgette (best), spinach, kale. Weigh down, leave overnight, remove.
• Bacter AE — biofilm booster
• Frozen bloodworm — occasional treat

Never overfeed shrimp tanks. Uneaten food rots quickly and spikes ammonia. Feed sparingly.

The breeding question

Amano shrimp cannot successfully breed in freshwater home aquariums.

They’re a “diadromous” species — larvae need brackish or full saltwater to survive. In captivity, females carry and hatch eggs normally, but the larvae die within days in freshwater.

Serious breeders can raise Amanos through a complex three-tank system (freshwater breeding tank → brackish larval tank → freshwater grow-out tank) but this requires precise salinity control, specific salt mixes, and weeks of hand-rearing microscopic larvae. Not for beginners.

Practical consequence: the population in your tank stays stable. Old shrimp die, but no new ones appear. Buy 8–10 Amanos and you’ll have 8–10 for years (minus attrition to age or occasional loss). Top up with new purchases every 1–2 years to maintain numbers.

Tank mates

Amanos are peaceful and safe with most community fish, though their size makes them more vulnerable to being eaten than cherry shrimp.

Excellent tank mates:

• Small tetras (neons, cardinals, embers) — all safe
• Rasboras
• Corydoras
• Otocinclus catfish
• Bristlenose plecs
• Cherry shrimp — no interbreeding, coexist fine
• Nerite snails
• Kuhli loaches
• Small gouramis (honey gouramis)

Marginal:

• Bettas — some individuals hunt shrimp
• Angelfish — juveniles OK; adults may eat Amanos

Avoid:

• Any cichlid larger than rams
• Larger tetras (Buenos Aires, serpae)
• Barbs (nippy)

Amanos are prey animals. Everything that can eat them eventually might.

Moulting

Every 4–6 weeks, adult Amanos moult. You’ll find translucent shells in the tank — DO NOT REMOVE them. The shrimp eats its own shell for calcium.

Freshly-moulted shrimp are white and soft; they hide for 24–48 hours until the new shell hardens. Fish tank mates will pick on them during this vulnerable period — heavy planting matters.

Failed moults: usually calcium/hardness deficiency. If GH is below 5, add Salty Shrimp GH+ or increase Indian almond leaves.

Algae control — the whole point

Amano shrimp specifically eat:

• Hair / thread algae — their signature ability
• Staghorn algae — with liquid carbon spot treatment as complement
• Biofilm on all surfaces
• Soft green algae — as maintenance

They do NOT reliably eat:

• Black beard algae
• Cyanobacteria
• Green spot algae

For a full algae strategy including Amanos, see our aquarium algae guide.

Recommended density: 1 Amano per 15L for algae control. So a 60L tank benefits from 4 Amanos; a 120L tank from 8. Add more for a heavier algae problem.

Common problems

Sudden death of the whole group — usually copper contamination (medications, plant food, tap water in agricultural areas). Test tap water for copper if concerns; use RO water for water changes.

Shrimp turning white and immobile — moulting difficulty or old age. Isolate to see if it moults successfully.

Shrimp jumping out of tank — Amanos sometimes climb filter cables and escape. Cover intake gaps.

Not eating algae — either not enough shrimp for the algae load, or wrong algae type (BBA, cyano — see algae guide).

Bottom line

Amano shrimp are the algae-eater workhorses of the freshwater hobby. Buy 5–8 for a 60L tank experiencing hair algae; watch the algae disappear over 2–4 weeks. They live 2–3 years and require essentially no additional feeding in a moderately-planted tank.

If breeding shrimp appeals, cherry shrimp are the answer. If algae control is the goal, Amanos are the answer. Many UK aquarists keep both.

Frequently asked questions

Do amano shrimp eat algae?

Yes — amano shrimp are the most effective algae-eating shrimp, eating hair, thread and staghorn algae plus biofilm. Stock about one per 15 litres for algae control.

Do amano shrimp breed in freshwater?

No. Their larvae require brackish water to survive, so they cannot breed in a normal freshwater tank. The population stays stable; top up with new stock every year or two.

Are amano shrimp better than cherry shrimp?

For algae control, yes — they are larger, longer-lived and eat more algae types. For colour and breeding, cherry shrimp are better. Many aquarists keep both.

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Related: cherry shrimp care, ghost shrimp care, get rid of algae in fish tank, best aquarium plants UK.

— Jaqline Smalling, FishForever