Invertebrate guide
Amano Shrimp
Caridina multidentata
Amano Shrimp are active, transparent freshwater shrimp famous for grazing on soft algae and leftover organic matter. They are larger and generally hardier than many ornamental dwarf shrimp, but they require stable, clean water, secure cover, and supplemental food.
Quick Reference
- Care difficulty
- Easy to moderate
- Adult size
- About 1.5-2 inches (4-5 cm); females are larger
- Lifespan
- About 2-3 years, occasionally longer
- Minimum tank
- 10 gallons recommended
- Temperature
- 65-78°F (18-26°C); 68-75°F (20-24°C) is a comfortable long-term range
- pH
- 6.5-8.0
- GH
- 5-15 dGH
- KH
- 1-10 dKH
- Diet
- Omnivorous grazer and scavenger
- Minimum group
- At least 3; 5-6 or more is preferable
- Community safe
- Yes, with peaceful community species
- Plant safe
- Yes
- Beginner-friendly
- Yes, if the tank is mature, covered, and stable
Key Takeaways
- Difficulty: Use a mature, covered, fully cycled aquarium with protected intakes.
- Minimum tank size: Supplement algae grazing with varied food.
- Beginner friendly: Adults live in freshwater, but successful reproduction requires a brackish-to-marine larval phase.
Natural habitat and life cycle
Amano Shrimp are native to coastal river systems of Japan, Taiwan, Korea, and nearby parts of East Asia. Adults inhabit freshwater streams and rivers with rocks, wood, leaf litter, vegetation, current, and abundant biofilm.
Their amphidromous life cycle connects freshwater adult habitat with estuarine or marine larval development. Newly hatched larvae drift downstream toward brackish estuaries or the sea.
Aquarium setup and stability
A standard rectangular aquarium with horizontal surface area, live plants, driftwood, rounded stones, porous rock, and shaded retreats provides grazing surfaces and shelter. A strong lid is strongly recommended because Amano Shrimp are skilled climbers.
Use a fully cycled, mature aquarium, cover filter intakes, seal lid gaps around tubing and cables, avoid copper contamination, and acclimate slowly to different water chemistry. Gentle to moderate current with good oxygenation is appropriate.
Behavior and compatibility
Amano Shrimp are peaceful, active grazers and scavengers. They roam widely, swim readily, and often rush to food. A small group encourages more natural activity; keep at least 3, with 5-6 or more preferred.
They are compatible with peaceful community species such as Otocinclus, small rasboras, small tetras, Corydoras, Nerite Snails, and Mystery Snails. Use caution with bettas, gouramis, larger barbs, loaches, dwarf cichlids, and curious fish; avoid puffers, goldfish, large cichlids, crayfish, and predators.
Feeding and molting
Amano Shrimp graze on biofilm, soft algae, diatoms, microorganisms, detritus, and decaying plant matter. Offer a varied diet based on shrimp pellets, algae wafers, spirulina foods, blanched vegetables, sinking community foods, dried leaves, and occasional protein.
Stable GH with adequate calcium and magnesium supports the exoskeleton. Provide hiding places, avoid disturbing freshly molted shrimp, and leave normal molts for mineral recovery unless disease or contamination is suspected.
Breeding and health
Breeding is very difficult in captivity. Eggs hatch into free-swimming larvae that require brackish-to-marine water; after several weeks and multiple larval stages, post-larvae must be transitioned back to freshwater.
Amano Shrimp are sensitive to ammonia, nitrite, chlorine/chloramine, copper, pesticides, low oxygen, and abrupt changes in temperature or dissolved solids. They do not establish a self-sustaining colony in normal freshwater.
Frequently Asked Questions
Will Amano Shrimp eliminate all algae from my aquarium?
No. They can be excellent grazers of soft algae and young hair algae, but they do not reliably eat every algae type and cannot fix excess light, nutrient imbalance, or poor maintenance. They also need a varied diet beyond algae.
Sources and Further Reading
- World Register of Marine Species taxonomy query: Caridina multidentata WoRMS Editorial Board