Amano Shrimp (Caridina multidentata)

The Amano Shrimp is the classic algae-grazing shrimp for planted freshwater aquariums. The accepted scientific name is Caridina multidentata; older supplier lists and hobby articles may still use Caridina japonica, so we keep that synonym here for clarity without treating it as a separate animal. Amanos are valued because they spend the day picking over leaves, wood, stone and glass for algae, biofilm and tiny edible particles, while staying peaceful with the right small fish and invertebrate tank mates.

This listing covers the live Amano Shrimp size options on the same Shopify product: 1-2 cm, 2-3 cm, 3-4 cm and 4-5 cm. They are practical working shrimp as well as interesting aquarium animals, but they still need a mature, stable tank. They are not a magic fix for an uncycled aquarium, high waste, poor light balance or aggressive fish. First-time customers can use WELCOME10 at checkout, and eligible live orders are covered by our Live Arrival Guarantee.

Source-Backed Species Notes

Petra lists this Amano Shrimp group as Caridina japonica with 20-26°C water, pH 6.5-8.3, 9-25 dGH hardness and an adult size around 4 cm. Modern taxonomy treats Caridina japonica as a junior synonym of Caridina multidentata; WoRMS lists Caridina multidentata Stimpson, 1860 as the accepted name, and Practical Fishkeeping reported the name change from C. japonica to C. multidentata. In plain English: if you have seen Amano Shrimp sold as Caridina japonica, you are usually looking at the same well-known Amano Shrimp under the older name.

Aquarium Glaser describes Amano Shrimp as one of the most popular aquarium shrimp and notes that they graze aufwuchs and algae from plants and decoration without harming healthy fish or plants. That matches their real value in aquascapes: they constantly browse surfaces, especially in mature aquariums with wood, moss, stone, Anubias, Java fern and other slow-growing plants where biofilm develops.

Who This Shrimp Suits

Amano Shrimp suit aquarists who want a peaceful, hard-working invertebrate for a cycled aquarium. They are especially useful in planted tanks, aquascapes and gentle community aquariums where soft algae and biofilm are part of the system. They are larger and more robust than many dwarf shrimp, so adult Amanos are less vulnerable to small peaceful fish than tiny Neocaridina shrimplets, though they are still prey for bigger or predatory fish.

They are not ideal for brand-new tanks, tanks treated with copper-based medication, unfiltered bowls, aggressive cichlid setups, puffer tanks, crayfish tanks or goldfish aquariums. Amanos are also skilled climbers and opportunistic explorers, so use a secure lid and avoid gaps around cables or filter pipes. If water quality drops or oxygen is low, shrimp may climb or gather near the surface before fish show obvious distress.

Aquarium Setup

Use a mature, fully cycled aquarium with zero ammonia and zero nitrite. A small group can live in a 40 litre aquarium, but 60 litres or more is better for a mixed planted community because it gives the shrimp more grazing space and makes water chemistry easier to keep stable. A group of five or more behaves more naturally than a lone shrimp, and larger planted tanks can support bigger groups when there is enough food.

Choose sponge filtration, a shrimp-safe internal filter, or an external filter with a guarded intake. Amano Shrimp like oxygen-rich water and gentle to moderate flow because it keeps detritus and fine foods moving across surfaces. They do not need a torrent, but stagnant corners and dirty substrate cause problems. Moss, driftwood, leaf litter, lava rock, smooth stones and plant roots all create grazing surfaces and hiding places for freshly moulted shrimp.

Dark sand or fine gravel makes them feel secure and helps their translucent body and dotted side markings stand out. They usually leave healthy plants alone. If you see them eating a leaf, the leaf is often already melting or covered in biofilm. In high-light planted tanks, Amanos are excellent helpers, but they still work best alongside balanced lighting, sensible fertiliser dosing, good circulation and regular maintenance.

Choosing the Right Size Option

The 1-2 cm and 2-3 cm options are useful when you want a group that can settle into an aquascape gradually. They are smaller on arrival, so give them dense moss, wood and plant cover, and avoid fish that investigate small invertebrates. The 3-4 cm and 4-5 cm options give more immediate presence and are better when the tank already has active community fish, provided those fish are peaceful and not large enough to eat shrimp.

Mixing sizes is possible in a well-planted aquarium, but spread food across the tank because larger Amanos are confident feeders. If you are building a clean-up crew for a mature tank, a group usually works better than one or two individuals. One Amano can graze, but a visible working group creates steadier algae pressure and shows more natural behaviour.

Water Parameters and Acclimation

Amano Shrimp are adaptable, but they dislike sudden changes. Match them to stable freshwater rather than chasing a perfect number. Petra's source range is 20-26°C, pH 6.5-8.3 and 9-25 dGH. For most UK planted community aquariums, a steady 21-25°C, neutral to slightly alkaline pH and moderate mineral content are a comfortable target. Avoid very soft water unless you deliberately remineralise it for shrimp.

Drip acclimation is strongly recommended. Float the sealed bag to equalise temperature, then slowly mix tank water into the transport water over 45-60 minutes. Net the shrimp into the aquarium rather than pouring transport water into the tank. After arrival, keep the lights low and avoid feeding heavily for the first day. A calm acclimation reduces failed moults and stress-related losses.

Moulting, Minerals and Shrimp-Safe Maintenance

Most Amano Shrimp losses happen around stress, acclimation or moulting rather than ordinary feeding. A healthy shrimp must shed its old shell as it grows, then harden the new shell with minerals from the water and diet. Failed moults can come from sudden parameter swings, very low mineral content, copper exposure, poor diet or shipping stress. Stable GH, careful water changes and a varied diet matter more than chasing a fashionable shrimp product.

Never use copper medication in a shrimp aquarium unless the product is explicitly invertebrate-safe and you understand the risk. Many fish treatments, plant dips and old pipes can expose shrimp to copper. When doing water changes, match temperature reasonably closely and avoid replacing huge volumes suddenly unless there is an emergency. Small, regular maintenance is kinder to shrimp than rare dramatic resets.

Feeding and Algae Control

Amano Shrimp eat soft algae, diatoms, biofilm, aufwuchs, decaying plant particles and small food leftovers. They are famous for helping with hair algae, but they prefer young, soft growth; they will not solve a severe algae outbreak if light, nutrients and maintenance are out of balance. Think of them as part of a clean-up crew, not a replacement for aquarium care.

Once visible algae is reduced, supplement them with quality shrimp pellets, algae wafers, blanched courgette, spinach, nettle, or small pieces of vegetable food. Feed lightly and remove leftovers before they foul the water. Amanos can be bold at feeding time and may carry food away from smaller shrimp. Spreading food in two places helps if you keep them with Cherry Shrimp or other dwarf shrimp.

What Amano Shrimp Will and Will Not Clean

Amanos are famous algae helpers, but honest expectations make better customers. They are very good at grazing film algae, soft green algae, early hair algae, biofilm and leftover particles. They are less useful against hard spot algae, severe black beard algae, cyanobacteria mats or algae caused by unstable light and nutrient balance. If the aquarium is over-lit, over-fed or under-maintained, shrimp can help but cannot fix the root cause.

They also do not replace a varied clean-up crew. Nerite snails are better on hard glass films, Otocinclus are gentle leaf grazers in mature tanks, and Amanos are excellent mobile pickers around wood, moss and plant bases. Combining the right animals with good husbandry gives a cleaner aquarium than expecting one species to do everything.

Tank Mates

Good tank mates include small rasboras, peaceful tetras, Otocinclus, small Corydoras, hillstream loaches in suitable flowing tanks, Nerite snails, peaceful livebearers and other compatible shrimp. They can live with Cherry Shrimp and many Neocaridina varieties when the tank is large enough and food is shared fairly. For colour-focused shrimp, compare with our Cherry Shrimp, Blue Rili Shrimp and Red Rili Shrimp.

Amano Shrimp with bettas can work only when the betta is calm, the tank is planted, and the shrimp are not tiny. Some bettas ignore adult Amanos; others harass them constantly. Avoid goldfish, large cichlids, puffers, predatory catfish, crayfish and any fish large enough to treat shrimp as food. A simple rule is useful: if the shrimp can fit in the fish's mouth, the pairing is not safe.

Breeding Reality

Female Amano Shrimp may carry eggs in a freshwater aquarium, but the larvae do not grow into young shrimp in normal freshwater. This species has an amphidromous life cycle: adults live in freshwater, while newly hatched larvae need saltier conditions before returning to freshwater as juveniles. That is why home breeding is much harder than breeding Cherry Shrimp or many Neocaridina varieties.

If your goal is easy colony breeding in freshwater, choose Neocaridina instead. If your goal is algae grazing, planted-tank activity and a larger, long-lived shrimp, Amano Shrimp are the better choice. Seeing a berried female is still a good sign that adults are healthy, even if you do not raise the larvae.

Common Buying Mistakes

The first mistake is buying Amano Shrimp for a tank that is too new. A tank can have clear water and still lack the biofilm, microbial stability and mature surfaces shrimp rely on. The second mistake is buying too few. A small group settles better and gives better algae-grazing coverage. The third mistake is mixing them with fish that are peaceful toward other fish but predatory toward shrimp.

The fourth mistake is confusing Amano Shrimp with colourful dwarf shrimp. Amanos are not chosen for solid red, blue or yellow colour; they are chosen for their size, activity and grazing ability. If you want a breeding colony with bright colours, look at Neocaridina. If you want a larger, tireless planted-tank grazer that usually will not breed in freshwater, Amano Shrimp are the specialist choice.

Appearance and Behaviour

Amano Shrimp are translucent grey, beige or olive with fine brown dots or dashes along the sides. Females are usually larger and fuller-bodied, often with dash-like side markings; males are smaller and slimmer with finer dot patterns. Their understated colour is exactly why they work visually in aquascapes: they do not fight the planting design, but they reward close watching.

Healthy Amanos spend most of the day grazing. They pick across leaves, wood, sponge filters and glass, then retreat under cover after moulting. A newly moulted shrimp may look pale and hide for a day while the new shell hardens. Leave the old moult in the tank unless it is clearly fouling; shrimp often eat moults to reclaim minerals.

Arrival Day Checklist

• Keep the aquarium lights low when the shrimp arrive.
• Float the sealed bag first, then drip-acclimate slowly.
• Do not pour transport water into the display aquarium.
• Release shrimp near plants, moss or wood so they can hide if needed.
• Leave feeding light for the first 24 hours unless the tank has no grazing surfaces.
• Check filter intakes and lids before release; Amanos explore.

After delivery, it is normal for shrimp to hide, look pale or spend time cleaning themselves. Give them stable water and cover rather than chasing them around the tank. If one molts soon after arrival, leave the moult in place unless it is obviously decomposing; the group may graze it for minerals.

Buying Notes

Choose the smaller size options when you want a group to settle into a planted tank from young, or the larger options when you want more immediate presence and algae-grazing impact. Because all sizes are the same species, do not mix this product up with selectively coloured shrimp sold under similar old Caridina japonica wording. The exact Petra/source image is included so you can see the real supplier animal alongside the existing aquarium gallery images.

For more detailed husbandry, read our Amano Shrimp care guide or browse the wider freshwater shrimp collection. For algae-eating fish alternatives, compare Amanos with the Chinese Algae Eater guide and smaller algae-grazing fish pages before choosing a clean-up crew.

Why Buy From Tropical Fish Co?

We keep the listing practical: accepted name, old synonym, real size options, care limits and compatibility warnings are shown clearly before you order. Your shrimp are packed for live delivery, and eligible livestock orders are supported by our Live Arrival Guarantee. Use WELCOME10 if this is your first Tropical Fish Co order, and choose a delivery day when someone can receive and acclimate the shrimp slowly.