Species · Shrimp & snails
Amano Shrimp
Caridina multidentata
The algae-eating workhorse shrimp — bigger and hardier than cherries, and the best natural crew for hair and soft green algae. Peaceful, won't overrun your tank, and copper-sensitive like all shrimp.
Difficulty: Beginner–Intermediate Shrimp / invert tank ✓ Fact-checked care guide
Quick facts
| Adult size | ~4–5 cm / 1.5–2 in (larger than cherry shrimp) |
|---|---|
| Minimum tank | ~40 L / 10 US gal (a common guide is roughly one amano per ~10 L for algae control) |
| Temperature | 21–26 °C / 70–78 °F |
| pH | 6.5–7.5 |
| Hardness | Moderate GH — needs dissolved minerals for healthy molting, like all shrimp |
| Filtration & flow | Gentle, cycled filtration; pre-filter the intake so shrimp aren't drawn in |
| Diet | Algae + biofilm grazer — supplement with shrimp food/algae wafers when algae runs low |
| Social | Keep a small group — they are social and bolder in numbers |
| Temperament | Completely peaceful |
| Lifespan | 2–3 years |
Overview
The amano shrimp (Caridina multidentata) is the algae-eating champion of the shrimp world — bigger, hardier and more industrious than cherry shrimp, and famous for tackling hair and soft green algae few other animals will touch.
It has a neat quirk: it effectively cannot breed in a home aquarium, because its larvae need brackish/salt water to develop. So it won't overrun your tank the way some inverts do — a feature, not a flaw.
💷 Costing it out? See how much a amano shrimp really costs to keep — the amano shrimp itself is usually the cheapest part.
Water & tank
Amanos like stable water around pH 6.5–7.5 at 21–26 °C / 70–78 °F, with enough GH (dissolved minerals) for healthy molting. As with all shrimp, stability matters more than hitting an exact number.
The hard rule for any invert: no copper — it is toxic to shrimp, so check medications, fertilisers and tap-water additives are invertebrate-safe. Keep them in a mature, cycled, planted tank with a pre-filter on the intake.
Feeding
A tireless grazer of algae and biofilm — a mature planted tank feeds them much of the time. When the algae runs low, supplement with shrimp food or algae wafers so they don't go hungry (a starving amano may pick at plants or scavenge harder).
Behaviour & tankmates
Utterly peaceful and safe with plants and fish. Being larger than cherry shrimp, adults are less likely to be eaten — but keep them away from large or aggressive fish that will still harass or eat them.
They are social and forage more confidently in a small group.
What to expect
Busy, comical grazers that clamber over everything hunting algae. Regular molting (translucent cast shells) is normal — leave the sheds; the shrimp eat them back for minerals.
Myths, kindly busted
“Amano shrimp will breed and take over my tank.”
They can't breed in a normal freshwater tank — their larvae need brackish/salt water — so the population won't explode.
“Amanos live on tank algae alone forever.”
They eat a lot of algae, but a clean tank runs out — supplement with shrimp food/algae wafers so they stay well-fed.
🐟 Did you know? — Amano Shrimp fun facts
Little true delights about the amano shrimp — each one checked against a named source, no pet-shop myths.
- Amano shrimp rarely breed in home tanks because their newly hatched larvae must drift to brackish or saltwater to develop before returning to freshwater. Wikipedia
- The shrimp is named for aquascaper Takashi Amano, who popularised it as an algae-cleaner in planted tanks in the early 1980s. Wikipedia
- Long sold to aquarists as Caridina japonica, the Amano shrimp was renamed Caridina multidentata after a 2006 study. Wikipedia
When to act
We triage, not diagnose — but these are worth a closer look (starting with a water test):
- Deaths after a water change, new medication, or fertiliser — suspect copper or a parameter swing; recheck what went in.
- A shrimp stuck mid-molt or dying after molting — usually a mineral/GH or sudden-change problem; check GH and stability.
Heading to a vet? Print the Amano Shrimp vet-prep sheet — what to bring, what to tell them, and the questions to ask.
Sources & further reading
- Aquarium Co-Op — Amano Shrimp (Caridina multidentata) care — Adult ~1.5–2 in / 4–5 cm; temperature 70–78 °F / 21–26 °C; pH ~6.5–7.5; lifespan 2–3 yr; premier algae eater; larvae need brackish/salt water (won't breed in freshwater); copper toxic to shrimp.
Written & fact-checked by The Finfern Team against the sources above — kind, general guidance, not a diagnosis. If something looks wrong, test your water and, if it persists, contact a fish-savvy vet.
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