Blue Rili Shrimp (Neocaridina davidi)

Understand the Blue Rili colour form

Blue Rili Shrimp is a blue aquarium colour form of Neocaridina davidi, a freshwater shrimp in the family Atyidae. The accepted scientific identity is Neocaridina davidi (Bouvier, 1904). It is native to Taiwan, eastern China, the Korean Peninsula and Vietnam and reaches 4 cm. This shrimp suits intermediate keepers prepared to use a mature biological filter, measured water, protected equipment, controlled feeding and careful tank-mate screening.

In nature, N. davidi is an omnivorous shrimp found in inland waters including lakes, ponds, rivers and streams. Wild-type shrimp are mottled brown, while aquarium selection has produced blue and several other colour morphs. Blue Rili is the colour-line name for this offer rather than a separate species, so filtration, food, water stability and adult space remain species-care decisions.

Its small size and peaceful temperament are approachable, but they do not make an immature, untested aquarium suitable. For a wider comparison of related colour forms, browse the cherry shrimp collection.

Choose the dispatch size and purchase unit

One purchase supplies one animal. Use the live size selector to choose between the labels 1 - 1,5 cm and 2 - 2.5 cm. These labels describe the approximate animal size at dispatch; they are not adult-size categories, pack sizes or life-stage guarantees.

The size you select is the size supplied, not the adult size. A smaller dispatch choice therefore needs the same long-term aquarium planning as a larger choice. Do not calculate permanent capacity from the dispatch measurement, because the filter, grazing area, companions and eventual group all continue to shape the usable space.

Sex is guaranteed only when the selected option explicitly states male or female. This Blue Rili Shrimp listing has no sex-guaranteed option.

The gallery should be used to understand the general shrimp shape and illustrative aquarium scenes rather than to select an individual by appearance. The gallery images are representative illustrations of this type of animal, not photographs of the animal supplied, so pattern and colours can differ from the live animal.

Plan around adult size, water and space

The species reaches approximately 4 cm at maturity, so use 4 cm as the cautious adult planning length. That figure is separate from the dispatch choices. Small body size does not make an immature or unstable aquarium suitable: shrimp are directly exposed to changing water chemistry and have little protection from an unguarded filter intake or predatory companion.

OATA's freshwater shrimp and snail guidance gives 17–27°C, pH 6.5–8.0 and 4–18°dH for the group; use these figures as a planning screen, not a species-specific optimum. Ammonia and nitrite should both measure zero. Keep the chosen temperature and chemistry stable, compare actual aquarium readings before transfer and avoid abrupt attempts to chase a preferred number.

OATA uses at least 10 litres as a general screen for a small shrimp group and recommends at least five for social shrimp. Our complete Cherry Shrimp Care Guide takes a more cautious house position: start planning from a mature, filtered 20-litre aquarium, then increase space for fish, other livestock and possible population growth. Neither volume is a shrimp-per-litre allowance.

Mature the filter before adding shrimp

A mature aquarium is one whose biological filter can process the planned livestock load while ammonia and nitrite remain at zero. Age alone does not demonstrate that state. Before adding shrimp, test the water, confirm that the filter is running correctly and check that routine feeding has not produced rising waste readings.

The RSPCA's filtration explanation describes why this matters: beneficial bacteria convert toxic ammonia to nitrite and then to safer nitrate. Shrimp still require that process even though each animal is small. A group, its food and every companion contribute to the biological load, while an interruption to circulation or careless filter cleaning can reduce bacterial capacity.

Use measured readiness

1. Run the complete system. Operate the filter, heating where needed, lighting and aeration in their intended positions.
2. Measure ammonia and nitrite. Both should remain at zero before livestock is introduced.
3. Check stability. Record temperature, pH and hardness so the transfer is based on real values rather than an assumption about local tap water.
4. Inspect the intake. Fit a fine guard or suitable sponge wherever a small shrimp or juvenile could be drawn in.
5. Stock gradually. Beneficial bacteria must adjust whenever livestock and feeding increase.

If this is a first aquarium, use our guide to prepare and mature a shrimp aquarium. OATA's freshwater aquarium setup guidance also supports cycling, water testing and gradual introduction. These steps prevent a calendar date from replacing the measurements that determine whether the system is ready.

Check capacity after each change

Repeat ammonia and nitrite tests after livestock or feeding increases instead of assuming that a previously mature filter has unlimited capacity. For example, if both readings were zero before an addition but either appears afterwards, stop further additions and review waste, feeding, circulation and filter operation. Resume the stocking plan only after repeated tests again show zero. This measured pause protects the group while preserving a clear link between the change and the result.

Keep water stable within the planning range

Choose a stable point within 17–27°C, pH 6.5–8.0 and 4–18°dH that also suits every other aquarium inhabitant. The goal is not to move water repeatedly towards the centre of each range. A stable measured value within the shared range is more useful than frequent adjustments that create rapid swings.

Test the aquarium rather than relying on a postcode, a tap-water description or the reading from another keeper's tank. Substrate, rock, top-ups and conditioners may all affect the final aquarium water. Our water chemistry guide explains what temperature, pH, general hardness, ammonia, nitrite and nitrate tell you. Use the water matcher to compare measured aquarium values with the planning range.

Use a thermostatically controlled, correctly sized and guarded heater only when room and aquarium temperatures cannot remain inside the chosen range. A cool room may need heating; a warm room needs an overheating plan. Decide from repeated measurements rather than the season alone.

OATA advises nitrate should not exceed 20 mg per litre above the normal tap-water level. Track the trend alongside feeding and maintenance, because a rising result can reveal accumulating waste before behaviour changes become obvious.

Compare trends, not isolated readings

Record water values at a consistent point in the maintenance cycle so one result can be compared fairly with the next. A pH or hardness reading taken before a water change may differ from one taken immediately afterwards, while temperature can vary with room conditions and lighting. When a value moves, repeat the test before acting, then review what changed in the aquarium. A gradual nitrate rise calls for attention to feeding, stocking and waste removal; an abrupt chemistry shift calls for a check of replacement water, substrate, rocks and recent products.

Build cover, grazing space and safe equipment

Arrange the aquarium around usable surfaces rather than open water alone. Aquarium-safe wood, rocks, plants and other structure provide sheltered areas where shrimp can graze and withdraw. OATA recommends gravel or sand and ideally live plants; suitable artificial plants and ornaments can provide shelter when live plants are not used.

Established surfaces matter because shrimp graze biofilm and soft growth as they move through the aquarium. Spread those surfaces across the tank so one feeding point or exposed ornament does not become the only usable area. Keep some access around equipment so the filter, intake and substrate can still be inspected and maintained.

Protect the vulnerable points

• Filter intake: fit a fine guard or suitable sponge where small shrimp could enter.
• Cover: provide moss, plants, wood, rock or other aquarium-safe structure with narrow sheltered spaces.
• Feeding access: reserve more than one reachable area when companions may arrive first or feed quickly.
• Inspection: retain a clear view of equipment and some open foreground so changes in activity are easier to spot.
• Real volume: account for the space displaced by substrate, wood, rocks and equipment when planning from 20 litres.

Plants are useful, but a planted appearance does not replace water testing or mature filtration. Likewise, visible algae does not demonstrate that enough complete nutrition is present. Treat the layout, filter and feeding plan as connected parts: surfaces support grazing, shelter reduces exposure and protected circulation maintains water quality without drawing shrimp into the intake.

Plan larger than 20 litres when fish or other livestock are included. Additional volume offers more headroom, but the footprint and arrangement still need to give the shrimp access to food and cover. A tall tank with little usable surface may offer less practical grazing space than its headline volume suggests.

Test the layout before arrival

Run the complete aquarium and watch how water moves around wood, rocks, plants and feeding areas. If debris collects heavily in one pocket, improve access for targeted cleaning rather than leaving a concealed waste trap. If the intake pulls loose plant material firmly against its guard, check that the protection remains secure and that flow is not becoming restricted. Place food temporarily in each intended feeding area and confirm that it can be reached and removed without dismantling the layout. These checks turn decorative structure into usable shrimp habitat.

Feed the group without fouling the water

Neocaridina davidi is omnivorous in nature, and aquarium shrimp spend time grazing biofilm and soft growth. Provide an appropriate complete sinking shrimp food as the nutritional base rather than expecting visible algae to meet every need. Follow the food manufacturer's directions, then adjust the portion from what the group actually consumes and what the water tests show.

OATA's broad routine suggests feeding freshwater shrimp two or three times a week and allowing at least 30 minutes for pellets or wafers to be eaten. For this colour form, observation should decide the final portion and timing. Group size, juvenile survival, grazing growth and competition can change, so a fixed amount may become excessive or insufficient.

Judge the next feed from the last one

Do not treat the shrimp as a substitute for aquarium maintenance or promise control of a named algae. Grazing can remove some soft growth, but uneaten food, solid waste and unsuitable algae still need direct management. Feed for the animals' nutrition, not as payment for a cleaning role.

Colour intensity is also a poor standalone feeding gauge. Lighting, substrate, stress, health, inherited colour and image processing can alter appearance. If colour changes alongside reduced feeding, inactivity or abnormal behaviour, test the water and assess the whole group rather than automatically adding more food.

Review feeding after the group changes

Reassess the portion whenever animals are added, juveniles appear or companions begin taking food more quickly. A useful decision sequence is access first, leftovers second and water trends third. If all shrimp reach the food but part of it remains after the feeding period, reduce the next portion. If nothing remains because fish remove it before the shrimp arrive, changing placement is more useful than simply increasing the total. When nitrate rises more quickly after a feeding change, restore the previous portion and inspect for trapped waste.

Maintain the aquarium with small, consistent actions

Carry out a 25% partial water change at least once a week, following OATA's freshwater invertebrate routine. Treat replacement tap water with a suitable conditioner to remove harmful chlorine or chloramine before it enters the aquarium. Match replacement conditions closely enough to avoid a sudden temperature or chemistry change.

Test ammonia and nitrite at least weekly and keep both at zero. Track nitrate as a trend rather than waiting for a visible problem. Record the results beside water changes, feeding adjustments and livestock additions; this makes it easier to connect a changed reading with a recent action.

Protect the biological filter

1. Check the filter for reduced flow or blockage during routine maintenance.
2. If cleaning is needed, rinse media lightly in aquarium water removed during the water change.
3. Do not run the filter media under the tap because any chlorine or chloramine present may kill the beneficial bacterial population established in the media.
4. Recheck circulation and the intake guard before leaving the aquarium.

Siphon accessible solid waste without stripping every surface bare. Shrimp use established grazing areas, while decomposing waste undermines water quality; the practical balance is targeted cleaning alongside preserved, healthy surfaces. Remove recurring uneaten food and debris from low-flow pockets, then leave clean aquarium-safe structure in place for grazing and cover.

After maintenance, watch the group before making another change. Check whether shrimp resume normal movement and feeding, whether the filter flow is steady and whether temperature remains stable. If a test result is unusual, repeat the measurement and investigate the cause instead of changing several parameters together. One measured adjustment is easier to assess than a chain of simultaneous corrections.

Increase livestock slowly. Each new animal and each feeding increase raises the load the filter must process, so extra water volume does not remove the need for gradual stocking and regular measurements.

Use a monthly pattern review

At the end of each month, compare the weekly records rather than judging the aquarium from its appearance alone. Stable zero ammonia and nitrite, consistent temperature and controlled nitrate indicate that the routine is matching the present load. Faster nitrate accumulation, recurring excess food or reduced filter flow shows where the routine needs adjustment. Change one factor at a time—for example the portion, waste-removal focus or filter check—then use the next measurements to judge whether that action helped.

Acclimatise slowly and check the first week

Prepare before arrival: test the aquarium, confirm zero ammonia and nitrite, and check the filter and intake guard.

Follow our current delivery and Live Arrival Guarantee policy.

Follow the arrival steps in order

1. Make sure someone is present to receive the parcel.
2. Start filming before opening it, with the parcel still sealed and the outer box visible. Continue filming as the parcel is opened, keeping the animal inside the sealed bag visible before anything is disturbed.
3. Float the bag for 20–30 minutes and acclimatise the shrimp slowly.
4. Release the shrimp without pouring the bag water into the aquarium.

Use a first-week checkpoint

Hiding after transfer can accompany a new environment or moulting, but do not use hiding alone as a diagnosis. Measure first. Check temperature, ammonia and nitrite, then inspect circulation, recent maintenance and tank-mate behaviour. A single empty exoskeleton may be a moult rather than a dead shrimp, so examine the aquarium calmly before intervening.

Add further livestock gradually rather than filling the planned community at once. The biological filter must adjust as waste and feeding rise. Slow additions also make compatibility easier to judge because you can identify which change preceded chasing, food exclusion or altered water readings.

Separate observation from intervention

During the first week, keep notes on feeding access, activity and water readings before changing the layout or routine. If the shrimp uses cover but emerges to graze and the tests remain stable, continued observation is more informative than repeated disturbance. If companions chase it, block food or force persistent concealment, use the prepared separation plan. If ammonia or nitrite appears, address the water-quality problem immediately and postpone every further livestock addition.

Respond to health and moulting changes

Learn the group's normal activity, feeding response and use of cover so a change is noticeable. OATA advises watching for increased inactivity, restlessness, unusual swimming, darker or paler colour, extra hiding, altered breathing effort, white spots, lesions, abnormal growths, exoskeleton damage, lost appendages, swelling, weight change and reduced interest in food.

Measure before treating

1. Test temperature, ammonia and nitrite immediately.
2. Review nitrate, pH and hardness beside earlier readings.
3. Check filter flow, aeration, heating and the protected intake.
4. Review recent animals, plants, decor, aerosols, foods, conditioners and maintenance.
5. Compare the affected shrimp with the rest of the group and record clear observations.

An empty shell is a normal result of moulting, while hiding may occur around a moult. Neither observation alone identifies illness. Intervene according to the complete pattern: water results, feeding, behaviour, physical signs and whether more than one animal is affected. Seek veterinary help when signs are severe, persistent or spreading.

Freshwater shrimp are sensitive to copper and will die if exposed even to low levels. Before adding any medicine, read the exact current label and every warning for shrimp or aquatic invertebrates. Do not transfer a dose or safety claim from another product, another crustacean or an informal recommendation. Identify the problem first and keep treatment decisions tied to the named product and the animals actually present.

Good biosecurity starts with inspection and dedicated wet equipment where practical. Keep transport water out of the display, clean shared tools appropriately and avoid releasing shrimp, aquarium water, plants or equipment contents into the wild. These actions reduce avoidable transfer risks without replacing mature filtration, suitable food or routine observation.

Match the response to the pattern

If one shrimp hides after a moult while the rest feed normally and the water tests remain stable, continue close observation without adding a treatment. If several shrimp become inactive after maintenance, compare the replacement water, temperature and conditioner use with the earlier routine. When physical damage, abnormal growths, persistent feeding refusal or altered breathing continues despite stable measurements, record the timing and visible signs and seek veterinary help. This sequence prevents a normal shell or brief concealment from triggering an unsuitable medicine.

Screen every tank mate before mixing

Blue Rili Shrimp are peaceful, but peaceful behaviour does not protect them from predation or feeding competition. Avoid fish able to fit the shrimp in their mouth and avoid species known to be predatory. Apply that rule to the animal's adult mouth size and behaviour rather than its name, shop category or size when first introduced.

Check the complete adult community

No fish is guaranteed safe for newly hatched shrimplets. A fish that ignores a 4 cm adult may still take much smaller young, and dense plants reduce exposure without removing the risk. If juvenile survival is the main goal, a shrimp-only aquarium removes fish predation from the decision, although filtration, crowding, food and health still require management.

Observe the first hours and days after any introduction. Chasing, repeated picking, exclusion from food or persistent hiding calls for separation rather than a longer trial. Keep a workable separation plan before mixing animals; a spare mature system is more useful than trying to improvise after behaviour changes.

Compatibility remains conditional because individual behaviour and aquarium layout can alter the outcome. Screen each proposed community by adult behaviour, shared water, feeding access, cover and the keeper's goal.

Work through the screen in order

Begin with predation: reject the pairing if the fish can swallow the shrimp or is known to hunt it. Next compare the stable water values required by every animal; overlapping labels are not enough if the aquarium cannot hold one shared point consistently. Then assess food access and territory in the actual layout. A companion that passes the mouth-size screen can still make the pairing unsuitable by taking every feed or excluding shrimp from cover. Finally, decide how much juvenile loss would conflict with the purpose of the aquarium.

Plan the group and future population

Shrimp are social, so plan for a starting group of at least five rather than keeping one as a permanent solitary display. One purchase supplies one animal, which means the purchase quantity should reflect the intended group while the live selector controls the dispatch-size choice.

Use 20 litres as the cautious starting policy for a small group in a mature, filtered aquarium. Plan larger when fish or other livestock share the system. Do not multiply litres by a fixed shrimp ratio: adult companions, real water volume, filtration, oxygen, grazing area, food access and possible juvenile survival determine how much headroom remains.

Choose the goal before choosing companions

• Peaceful display group: prioritise stable water, visible grazing surfaces and companions that pass the mouth-size and behaviour screens.
• Maximum juvenile survival: use a shrimp-only aquarium with protected intakes and dense usable cover.
• Single-colour group: keep colour-line planning separate from core welfare and allow space for possible growth in numbers.
• Mixed community: increase the aquarium plan beyond the small-group starting point and reserve feeding access for shrimp.

N. davidi females carry eggs externally beneath the abdomen, and young hatch as benthic juveniles rather than requiring an Amano-style saline planktonic phase. This biology does not guarantee a colony, a sex mix or a rate of population growth. Plan capacity conservatively and protect the intake even when breeding is not the goal, because an unsexed social group may change over time.

Review the plan after the first month. Compare group visibility, feeding access, waste trends and water tests with the first week. If grazing space is crowded, food competition rises or nitrate begins climbing more quickly, reduce further additions and adjust the aquarium before the pressure becomes a health problem.

Use a capacity checkpoint before adding more

Pause at the end of the first month and answer four questions: do ammonia and nitrite remain at zero, is nitrate rising at the expected rate, can every shrimp reach food, and does the group still have sheltered grazing space? A yes to all four supports continuing the existing routine, not automatic expansion. A problem in any one area means further additions should wait. Improve the limiting factor, repeat the measurements and observe another maintenance cycle before reconsidering the plan.

Answer common Blue Rili Shrimp questions

How big does Blue Rili Shrimp get?

Blue Rili Shrimp reaches approximately 4 cm at maturity, so plan its aquarium around that adult length rather than its dispatch size.

What size aquarium does Blue Rili Shrimp need?

Start with a mature, filtered aquarium planned from 20 litres under the Tropical Fish Co care policy, then use more space when fish, other livestock or population growth are included.

How many Blue Rili Shrimp should I keep together?

Keep Blue Rili Shrimp in a social group of at least five under OATA's group guidance; one purchase supplies one shrimp, so plan the purchase quantity around the intended group.

Is Blue Rili Shrimp suitable for beginners?

Blue Rili Shrimp is classed as intermediate because it needs mature filtration, zero measured ammonia and nitrite, stable water, careful feeding and screened companions.

What does Blue Rili Shrimp eat?

Blue Rili Shrimp is omnivorous; provide an appropriate complete sinking shrimp food, allow grazing on established biofilm and soft growth, and reduce the next portion when food repeatedly remains.

What temperature and pH does it need?

OATA's freshwater shrimp group guidance gives 17–27°C, pH 6.5–8.0 and 4–18°dH; keep ammonia and nitrite at zero and avoid abrupt changes.

Is this shrimp aggressive or likely to nip fins?

This shrimp is classed as peaceful. Protect it from predation and feeding competition by screening every proposed companion and observing behaviour after introduction.

Which kinds of animals can it live with?

Avoid fish able to swallow shrimp and species known to be predatory; screen every pairing for adult mouth size, hunting and territorial behaviour, shared water, food access, cover and risk to juveniles.

How does it arrive alive in the UK?

Film every delivery continuously from the sealed parcel as it is opened, keeping the animal inside the sealed bag visible before anything is disturbed. Make sure someone is present to receive it, float the bag for 20–30 minutes, then release the shrimp without pouring bag water into the aquarium.

Reference the care and identity bibliography

• World Register of Marine Species — accepted name, authorship and family.
• Wikipedia: Neocaridina davidi — species natural history, adult length and selectively bred colour morphs.
• OATA freshwater shrimp and snail guidance — water screens, group keeping, feeding, maintenance and compatibility.
• RSPCA aquarium environment advice — biological filtration and waste processing.
• OATA freshwater aquarium setup guidance — cycling, testing and gradual stocking.