Amano Shrimp Care: Feeding, Tank Mates, and Why Breeding Is So Hard — a Guide from the Shrimp's Home Country
The shrimp you know as the Amano shrimp lives in the clear upstream rivers of our home country. In Japan we call it Yamato-numa-ebi (ヤマトヌマエビ) , the "Yamato swamp shrimp." The English name comes from Takashi Amano, the Japanese aquascaper who showed the rest of the world how much algae it eats. Our maintenance teams in Tokyo have used it in hundreds of client aquariums because nothing else cleans hair algae off plants as thoroughly.
Amano shrimp are hardy, but we regularly hear the same complaint from beginners: "they keep dying on me." Almost every time, the cause is water that changed too fast or summer heat. Below we cover water, feeding, tank mates, and why breeding them at home rarely works.
What Is an Amano Shrimp?
Caridina multidentata is a freshwater shrimp in the family Atyidae, growing to about 1.2–2 inches (3–5 cm), with females noticeably larger than males. In the wild it lives in the clean middle and upper reaches of Japanese rivers.
Many keepers don't realize that Amano shrimp don't spend their whole lives in freshwater. Females release hatched larvae that drift downstream into brackish estuaries or the sea. The larvae develop there, become tiny shrimp, and then climb back upstream, sometimes for miles. That life cycle explains both how tough they are and why you cannot breed them in your tank (more on that below).
Water Parameters and Tank Setup
Amano shrimp thrive in an ordinary tropical community tank. When they fail, it is almost always water stability or temperature.
| Parameter | Ideal range | Notes |
|---|---|---|
| Temperature | 68–82°F (20–28°C) | Native to temperate Japan, they winter outdoors in our ponds as long as the water doesn't freeze. Heat is what kills them: use a fan or cooling in summers above 86°F (30°C) |
| pH | 7.0–7.5 (neutral to slightly alkaline) | Slightly acidic water is also fine in practice |
| Acclimation | Drip method, 1 hour+ | Skipping this causes most "mystery deaths" in the first week |
In February 2024, a faulty cooler on a small client tank showed 40°C (104°F) on its display and kept chilling the water until it was too cold. The neon tetras, pristella tetras and platies all died. Two honey gouramis and the Amano shrimp were unharmed.
When our maintenance staff do a large water change on a shrimp tank, they refill slowly. A sudden swing in water chemistry can shock shrimp that have lived happily in the tank for months.
Amano Shrimp and Planted Tanks
Planted tanks are where the species made its name. The Nature Aquarium style pioneered by Takashi Amano depends on lush plants and spotless glass, and Amano shrimp do much of the cleaning. They eat the stubborn hair algae and fuzz algae that grow on plant leaves, which is exactly the algae you can't remove by hand.
They do occasionally graze on tender new plant shoots. If your plants are getting eaten, you have too many shrimp for the algae available, so reduce their number or feed them more.
For example, in one client tank where we had added seven Amano shrimp two months earlier, our staff noted that the shrimp were eating the java fern and planned to remove a few of them at the next visit.
In our client aquariums in offices, clinics and restaurants, we add Amano shrimp at roughly one per 2–3 gallons whenever hair algae appears on plants, and cut feeding slightly for two weeks. In most tanks the visible algae is gone within 10–14 days, and the shrimp keep it from coming back. It is cheaper and healthier for the tank than any chemical algae treatment we've tried in over 20 years of maintenance work.
What to Feed Amano Shrimp
In an established tank they mostly feed themselves: algae, leftover fish food, and biofilm on the substrate. To keep them in top condition, offer a sinking shrimp food once or twice a week, in small amounts. If you keep other algae eaters (otocinclus, plecos), watch that the algae supply doesn't run out. Shrimp can quietly starve in a spotless tank.
Amano Shrimp vs. Cherry Shrimp
In the US, the other shrimp everyone keeps is the cherry shrimp (Neocaridina davidi). In Japan we keep its wild cousin, the Minami-numa-ebi (ミナミヌマエビ) , and the comparison is a daily conversation in our work. Choose based on your goal:
| Amano shrimp | Cherry shrimp | |
|---|---|---|
| Size | 1.2–2", big and easy to see | ~1" — smaller |
| Algae-eating power | Much stronger. Handles tougher, mature algae; good for large tanks | Light grazing only |
| Breeding in freshwater | Virtually impossible | Easy. Colonies grow on their own |
| Best for | Algae control, planted tanks | Color, breeding projects, nano tanks |
In one client's freshwater terrarium, Amano shrimp escaped from the tank, so our staff noted that Minami-numa-ebi should be added there instead.
Why You Can't Breed Amano Shrimp in Your Tank
Females carry eggs readily in captivity; that part happens all the time. But the hatched larvae must develop in brackish water, feeding on plankton, and then be moved back to pure freshwater at exactly the right stage. Reproducing that trip to the sea and back takes several tanks, a live plankton culture, and weeks of daily salinity adjustments. Even in Japan, only dedicated breeders manage it. Our advice is to enjoy the berried females and buy your next generation.
Tank Mates: Safe and Unsafe
Amano shrimp are peaceful and never attack fish. The real question is whether your fish will eat the shrimp.
| Good tank mates | Avoid |
|---|---|
| Small peaceful community fish: tetras, rasboras, corydoras, otocinclus, medaka (ricefish) | Angelfish and medium/large cichlids, goldfish large enough to swallow them, loaches with a taste for shrimp, and any predatory fish, which will treat shrimp as live food |
Two more notes from our installation work. If the tank also has dedicated algae grazers, provide shrimp food so nobody starves. And in tight quarters, Amano shrimp may bully much smaller ornamental shrimp such as crystal or bee shrimp, so unless the tank is very large, keep those colonies separate.
