Amano shrimp (Caridina multidentata) are freshwater grazers that need a mature aquarium, appropriate food, and peaceful tankmates. They can help with soft algae, but they do not remove the need for water changes or solve the cause of an algae outbreak. Their transparent bodies and busy feeding behavior make them interesting animals in their own right.
Amano shrimp care at a glance
| Requirement | Practical starting point |
|---|---|
| Adult size | About 1.5–2 inches; females usually grow larger |
| Aquarium | Established 10-gallon or larger tank with covered openings |
| Temperature | 68–80°F; keep conditions stable and suitable for all inhabitants |
| Water | pH around 6.5–7.5; measurable mineral hardness, not untreated pure RO water |
| Food | Natural grazing plus small portions of suitable sinking food |
| Breeding | Adults live in freshwater; larvae require a separate saline rearing stage |
The size and water ranges above follow Fluval’s Amano shrimp profile (PDF). They are care guidelines, not targets to reach by abruptly changing your aquarium.
Identification and buying
Amanos have translucent grayish bodies with a row of dark markings along each side. Males tend to show dots; females often have more elongated marks. Older labels may use the name Caridina japonica. Similar-looking shrimp are sold under broad common names, so ask for the scientific name when buying.
Choose active shrimp that are grazing or moving normally. Ask whether they are captive-bred or collected, how long the store has held them, and what water they are in. A bargain price is less useful than healthy animals and clear acclimation advice. Do not select a fixed male-to-female ratio unless you have a specific breeding project.
Set up a mature, escape-resistant aquarium
A 10-gallon tank is a useful minimum starting size for this guide; more space helps when adding fish. Start with a modest group, such as four to six, in an appropriately maintained tank rather than applying a rigid shrimp-per-gallon formula. Food supply, cover, and existing inhabitants matter.
Use established biological filtration and confirm that ammonia and nitrite are undetectable. Waiting six weeks is not a substitute for testing. Shrimp benefit from a tank that has developed grazing surfaces as well as a functioning filter. Aqueon’s freshwater shrimp guide recommends mature aquariums and protected filter intakes.
Add plants, wood, and sheltered spaces. Fit a sponge guard to an exposed intake and close gaps around hoses and cables without blocking ventilation. Good surface movement supports oxygen exchange; a powerful extra pump is not automatically necessary. Use a heater if the room cannot maintain suitable conditions.
Water changes, minerals, and acclimation
Condition replacement tap water for chlorine and chloramine and match temperature closely. Make regular partial water changes, guided by tests and feeding, rather than allowing waste to build up between major cleanouts. Keep a record of pH and general hardness (GH) so you can recognize a change.
Do not add crushed coral or mineral supplements simply because a shrimp is hiding. Test first: additives can change more than one water parameter. If using reverse-osmosis water, prepare and verify an appropriately remineralized supply before use.
Ask the supplier for acclimation instructions suited to the shipping method and water difference. Avoid sudden changes and prolonged exposure to deteriorating transport water. Check every medication’s label for invertebrate safety; copper-based fish treatments can be dangerous to shrimp. Treat fish separately when a product is unsuitable for the shrimp aquarium.
Feed the shrimp, not just the algae
Offer small amounts of sinking shrimp food and observe whether all animals can reach it. An occasional small piece of softened vegetable can provide variety; remove leftovers before they foul the water. Spread food between a few locations if large shrimp monopolize a pellet.
Amanos graze biofilm and some filamentous algae, but results vary with the algae present and other food available. Do not starve them to make them clean. Manually remove troublesome growth and review lighting, feeding, and plant health. Eating waste food still produces shrimp waste.
Molting: what is normal?
An empty, translucent shell can be a shed exoskeleton. Hiding afterward is normal while the new shell hardens. Leave an obvious empty molt for the shrimp to graze, but do not assume every pale, motionless shape is a shell. Check for tissue inside and look for the living shrimp before deciding.
If several shrimp become inactive, try to climb out, or die close together, promptly check ammonia, nitrite, temperature, aeration, and anything recently added to the water. Repeated losses or failed molts need investigation; adding minerals blindly may make conditions worse.
Tankmates: peaceful does not always mean safe
Small fish such as ember tetras may share suitable water conditions with adult Amanos. Avoid fish large enough to swallow them and species that hunt crustaceans. Newly molted shrimp are especially vulnerable. Bettas vary individually: planted cover reduces exposure but does not guarantee safety. See our betta and shrimp compatibility guide.
A shrimp-only aquarium removes fish predation risk. If mixing Amanos with blue velvet shrimp, make sure the smaller shrimp also get food.
Why eggs do not produce a freshwater colony
A female may carry eggs beneath her abdomen and release tiny larvae. Unlike cherry shrimp, Amanos do not normally complete this life cycle in an ordinary freshwater aquarium. Aquarium Co-Op’s Amano guide explains the larvae’s need for highly brackish or salt water.
Do not salt the community tank or move the adult female into seawater. Successful rearing needs a separate planned system, measured salinity, suitable microscopic food, and a managed return to freshwater after development. It is a specialist project, not a quick change to normal care. For most keepers, enjoying healthy adults is a better starting goal than attempting to raise every batch of eggs.