Carbon Rili Shrimp (Neocaridina davidi)

Recognise the Carbon Rili form

Carbon Rili Shrimp are dark ornamental freshwater shrimp native to Taiwan, eastern China, the Korean Peninsula and Vietnam. The accepted scientific name is Neocaridina davidi, an atyid shrimp that reaches approximately 4 cm. This is an intermediate-care animal suited to keepers who can provide a mature biological filter, measured water, established grazing surfaces and controlled feeding.

The World Register of Marine Species lists Neocaridina davidi in the family Atyidae. The older label Neocaridina denticulata may also appear in aquarium naming.

Carbon Rili describes a selected aquarium colour form rather than the wild colour. Wikipedia’s summary of N. davidi describes the wild type as mottled brown and records selectively bred forms in many colours. Carbon Rili animals are selected for dark colour and contrasting sections, but pattern strength and coverage can differ between individuals. Browse the current cherry shrimp collection when comparing this dark line with other colours.

Its peaceful temperament does not remove the need to screen fish carefully: a small shrimp can still be treated as prey. Plan the aquarium around stable water, safe filtration, accessible food and companions that cannot swallow the shrimp.

Choose the dispatch size and purchase unit

One purchase supplies one Carbon Rili Shrimp in the option selected on the live size selector. The size choices are 1–1.5 cm and 2–2.5 cm. Use the selector to choose the required dispatch size rather than treating either measurement as the animal’s final length.

The size you select is the size supplied, not the adult size. The natural-history reference records mature Neocaridina davidi at approximately 3–4 cm, so plan equipment, companions and access to food around an adult shrimp approaching 4 cm. A larger dispatch option is simply a larger animal at dispatch; it does not guarantee sex, maturity, stronger colour or a particular pattern.

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

The gallery images are representative of this type of animal rather than photographs of the exact animal supplied, so colours can look slightly different from the live animal. The retained gallery scene shows a mostly black, pale-speckled shrimp rather than a sharply divided Carbon Rili pattern, so make your choice for the named colour line rather than one exact arrangement of markings.

Choose by aquarium readiness first and dispatch size second. A smaller shrimp still needs established grazing surfaces and protection from filter intakes, while either size needs companions screened against the shrimp’s present size and expected adult length.

Check the core care plan before choosing

Start with a mature, filtered aquarium holding measured water. Tropical Fish Co uses 20 litres as a cautious starting policy for a small group, above OATA’s general 10-litre screen for small freshwater shrimp. The larger figure creates more headroom for equipment, feeding, temperature movement and population growth; it is not a shrimp-per-litre formula. Read the complete Cherry Shrimp Care Guide when planning the whole system.

OATA’s freshwater shrimp and snail sheet gives 17–27°C, pH 6.5–8.0, general hardness of 4–18°dH and carbonate hardness of 3–15°dKH as broad group guidance; use these figures as a planning screen rather than a species optimum. Ammonia and nitrite should remain at zero mg per litre, while nitrate should not exceed 20 mg per litre above the normal tap-water level.

Provide plants or other aquarium-safe cover, established surfaces for grazing and a protected filter inlet. Feed an appropriate complete shrimp food alongside natural grazing, and add livestock gradually so the biological filter can adjust to increased waste and feeding.

Build a mature, filtered aquarium

A mature aquarium is one in which the biological filter reliably processes the planned livestock load and water tests remain stable. The RSPCA’s aquarium filtration guidance explains that beneficial bacteria convert toxic ammonia first into nitrite and then into the safer nitrate. For shrimp, confirm ammonia and nitrite at zero mg per litre before introduction and continue testing after livestock and feeding increase.

Prepare the aquarium rather than relying on its age. A tank that has stood for several weeks can still be unsuitable if its filter has not developed enough beneficial bacteria, while a mature filter can be disrupted by chlorine, blockage or unsuitable cleaning. The OATA freshwater aquarium setup guidance supports cycling, regular testing and gradual stocking.

Give the shrimp safe working surfaces

• Use aquarium gravel or sand and provide live plants where practical.
• Add aquarium-safe structure that creates sheltered surfaces and visible grazing routes.
• Cover an intake that could draw in a small shrimp or juvenile.
• Keep access to the filter clear enough for checks and maintenance.
• Leave enough open space to observe feeding, activity and waste.

Plants, wood, rock, ornaments and filter surfaces all increase the area the shrimp can explore. Established surfaces support grazing, but they do not replace complete food or water testing. Avoid stripping every surface clean at the same time because that removes grazing area and can disturb the aquarium’s routine.

Use real water volume after substrate, equipment and decoration when assessing capacity. Twenty litres is the starting policy for a small group, not permission to crowd a tank. Increase space when fish or other livestock share the aquarium, and reserve headroom for feeding errors or juvenile survival. The freshwater shrimp setup guide provides a wider preparation sequence for a first shrimp aquarium.

Keep water stable and measured

Choose stable conditions within 17–27°C, pH 6.5–8.0, 4–18°dH general hardness and 3–15°dKH carbonate hardness. Stability is an active routine: measure the aquarium, prepare replacement water consistently and investigate trends before they become sudden changes. The aquarium water chemistry guide explains what each measured value means, while the water matcher helps compare recorded aquarium values with the planning range.

Use a heater only when measured room and aquarium temperatures cannot remain stable within the chosen range. In a cool room, select a correctly sized, guarded and thermostatically controlled heater. In warm weather, monitor the upper temperature rather than assuming a heater setting prevents overheating.

Test at least weekly and whenever behaviour, feeding or appearance changes. A single acceptable result is useful, but a written sequence shows whether the system is stable. Record temperature, ammonia, nitrite and nitrate together; include pH and hardness when investigating a change or preparing for new shrimp.

Treat replacement tap water with a suitable conditioner before it enters the aquarium. Match its temperature closely and keep the preparation method consistent. Avoid abrupt attempts to force pH or hardness towards one preferred number: first identify why the value moved, then correct the cause through measured, gradual steps.

Feed grazing shrimp without fouling the water

Neocaridina davidi is an omnivore in nature and spends much of its time picking food from submerged surfaces. In the aquarium, Carbon Rili Shrimp graze biofilm and some algae, but those resources vary from tank to tank. Use an appropriate complete shrimp food so the group is not expected to survive on incidental growth alone.

OATA recommends feeding freshwater shrimp two or three times a week. Offer a small portion that the group can reach, leave a pellet or wafer for at least 30 minutes so the shrimp have time to feed, then remove recurring excess before it breaks down. Follow the food manufacturer’s directions while adjusting the portion to the actual group, grazing area and presence of other livestock.

Judge the next portion from what you see

Feeding more because the shrimp are small is not a safe shortcut. Uneaten food releases waste as it decays, increasing the load on the filter and raising the risk of ammonia, nitrite or nitrate problems. Spread access across the group without scattering so much food that it disappears into inaccessible areas.

These shrimp may graze nuisance algae, but they are not a treatment for a named algae problem or a replacement for maintenance. Control excess nutrients, lighting and waste through the aquarium routine, then feed the shrimp as animals with their own nutritional needs.

Maintain the aquarium each week

At least once every week, carry out a partial water change of 25%. Prepare the replacement water with tap-water conditioner to remove chlorine or chloramine, and match it closely enough to avoid a sudden temperature or chemistry change. Use a siphon where practical to remove solid waste while leaving useful planted and grazing areas intact.

Use one repeatable maintenance sequence

1. Measure temperature, ammonia and nitrite before disturbing the tank.
2. Review nitrate against the normal tap-water level and recent results.
3. Prepare conditioned replacement water using the same measured method.
4. Remove approximately 25% while siphoning accessible solid waste.
5. Check the filter inlet, outlet and protective guard for blockage or gaps.
6. Refill gradually and observe the shrimp as circulation resumes.
7. Record the results so the next weekly test has a useful comparison.

Check the filter for reduced flow or blockage every week. When filter media needs cleaning, rinse it lightly in aquarium water removed during the water change rather than under the tap. Chlorine or chloramine can damage the beneficial bacteria that support biological filtration.

A larger clean is not automatically a better clean. Avoid combining a major filter clean, deep substrate disturbance, large water change and livestock addition on the same day. Spreading necessary work reduces the chance that several small disruptions create one large change.

Establish a dependable first-month baseline

Use the first four weekly maintenance sessions to learn how the aquarium responds between water changes. Record the test results before each change, note how much food has been offered and check whether waste collects in the same places. A repeatable nitrate rise may point to excess feeding or livestock load, while inconsistent temperature or pH can reveal that replacement water preparation needs attention.

• After week one, confirm that ammonia and nitrite have remained at zero mg per litre.
• After week two, compare filter flow and intake condition with the first inspection.
• After week three, check whether the feeding portion leaves recurring waste.
• After week four, use the four records to set a routine rather than guessing from one result.

If a value changes after maintenance, compare the aquarium before and after the water change. That simple check separates an existing tank trend from a mismatch introduced with replacement water and helps you make one measured adjustment instead of changing several parts of the routine together.

Keep wet equipment dedicated to the aquarium where practical. Review any new plant, decoration, food or treatment before use, because contamination can enter during routine care as easily as during livestock introduction.

Acclimatise the shrimp with a prepared plan

Prepare the aquarium before the parcel arrives: test the water, check the protected filter inlet and make sure someone can receive the live animal. Read the current delivery and Live Arrival Guarantee policy before the delivery window so the receipt and claim steps are clear.

Follow the arrival sequence

1. Receive the parcel in person.
2. Start filming before opening, with the parcel still sealed and the outer box visible. Continue in one take as the parcel is opened and show the animal still inside the sealed bag.
3. Float the bag for 20–30 minutes before releasing the shrimp.
4. Never pour the bag water into the aquarium.

Floating addresses temperature movement; stable aquarium chemistry, zero ammonia and nitrite, and a prepared biological filter must already be in place. Do not use acclimatisation to compensate for an unsuitable aquarium.

Keep feeding restrained during the first settling period. Once the shrimp begins normal surface grazing, use the established feeding routine rather than adding a large welcome meal. Check that the animal can move away from flow, reach cover and avoid the filter intake.

Use the first week as a settling checkpoint

Keep the established aquarium routine steady during the first week. Observe whether the shrimp moves between cover and grazing surfaces, can reach food and remains clear of the intake. Test immediately if activity or feeding changes, then compare the result with the measurements taken before arrival.

• On the first day, prioritise safe movement, cover and stable temperature.
• At the first feed, confirm that the shrimp can reach a modest portion without competition.
• At the next weekly test, confirm ammonia and nitrite remain at zero mg per litre.
• Before adding more livestock, check that feeding and filtration have settled without a worsening nitrate trend.

Avoid moving decorations, changing the feeding method and adding companions at the same time. Holding the routine steady makes observation more useful because a change in behaviour or water quality has fewer possible causes.

Add further livestock gradually. Every increase in animals and food asks the beneficial bacterial population to process more waste, so allow the aquarium to demonstrate stability before the next change.

Respond to behaviour and health changes

Learn the group’s normal activity so a change is easy to recognise. Watch swimming and walking behaviour, colour, hiding, breathing effort, body condition, feeding response and the exoskeleton. A single observation rarely identifies a cause, so start with measurements and recent events rather than immediate medication.

If behaviour changes, work in this order

1. Measure temperature, ammonia and nitrite immediately.
2. Review nitrate, pH and hardness against recent results.
3. Check filter flow, aeration, heating and the protected inlet.
4. List recent water changes, new livestock, plants, decorations, food and treatments.
5. Compare the affected shrimp with the rest of the group.
6. Seek suitably qualified aquatic or veterinary help when signs are severe or persist.

Freshwater shrimp are sensitive to copper, including low exposure. Read the exact label and every invertebrate warning before adding any medicine or treatment. Use only a product whose current directions are compatible with shrimp, and identify the problem before treating the display aquarium.

Do not add new livestock while unexplained changes continue. Stabilise the system, retain written test results and make one justified change at a time. That sequence preserves the clues needed to distinguish a filtration problem, abrupt environmental change, contamination or health condition.

Screen every companion as a predation risk

Carbon Rili Shrimp are peaceful, but compatibility depends on what every companion can do to a small crustacean. Avoid fish able to fit the shrimp in their mouth and species known to be predatory. Apply the screen to the shrimp’s current dispatch size as well as its expected adult length, because the 1–1.5 cm option is especially easy for a fish to swallow.

Check the complete adult community

• Compare adult mouth size with the smallest shrimp being introduced.
• Consider hunting, territorial and food-guarding behaviour.
• Confirm overlap across temperature, pH and hardness.
• Make sure shrimp can reach food before faster companions remove it.
• Provide cover that remains useful after plants are trimmed.
• Protect vulnerable juveniles and newly moulted shrimp from access.
• Keep a separation plan ready if behaviour changes.

No fish is guaranteed safe with newly hatched shrimplets. Dense planting and other cover can reduce exposure, but cover does not turn a predator into a suitable companion. Decide whether the goal is a mixed display or maximum juvenile survival before choosing fish.

For a mixed aquarium, increase space beyond the 20-litre starting policy and account for every adult animal. Compatibility requires shared water conditions, manageable waste, protected feeding access and behaviour that remains acceptable after introduction.

Plan a social group with room to grow

OATA’s freshwater shrimp guidance says social shrimp should be kept in groups of at least five. Because one purchase supplies one animal, choose the basket quantity needed for the planned group while checking that the aquarium has mature filtration, enough grazing area and room for every existing inhabitant.

Do not turn the 20-litre starting policy into a permanent density formula. Aquarium capacity depends on real water volume, filter performance, oxygenation, feeding area, maintenance, companions and possible population growth. A group of five in a mature planted aquarium is a planning starting point, not a promise that any number remains suitable indefinitely.

Plan the group in this order

1. Confirm the filter holds ammonia and nitrite at zero mg per litre.
2. Calculate usable space after substrate, wood, plants and equipment.
3. Reserve several accessible grazing and feeding surfaces.
4. Screen every fish against the smallest shrimp and possible juveniles.
5. Leave headroom for increased feeding and biological waste.
6. Check water tests after the group settles before adding anything else.

A shrimp-only aquarium is the clearest choice when juvenile survival is important. It removes fish predation and reduces feeding competition, although filtration, crowding, equipment safety and water quality still require active management. A mixed display accepts greater uncertainty, especially for very small shrimp.

Work through a group-planning example

If the aquarium already contains other animals, do not subtract their number from a theoretical shrimp allowance. Instead, check whether the mature filter holds ammonia and nitrite at zero, whether several shrimp can feed without being displaced and whether the shared water range suits every inhabitant. Increase the planned volume when companions add waste, consume the same food or reduce usable cover.

For a shrimp-only 20-litre plan, begin with the small-group policy rather than filling every visible surface immediately. Observe feeding access and weekly test trends as the animals settle. If juveniles later survive, treat that population increase like any other livestock addition: reassess feeding, nitrate movement, filter performance and available grazing area before increasing the group again.

When the aquarium cannot support at least five together, improve the system or choose a different plan rather than keeping one shrimp as a shortcut. Social care, filtration and space must be solved together.

Reassess capacity as the population changes. Feeding competition, rising nitrate or declining stability are reasons to reduce inputs, improve the system or separate animals rather than relying on a fixed shrimp-per-litre calculation.

Answer common Carbon Rili Shrimp questions

How big does a Carbon Rili Shrimp get?

Wikipedia records mature Neocaridina davidi at approximately 3–4 cm, so plan for an adult length of about 4 cm rather than the dispatch size.

What size aquarium does Carbon Rili Shrimp need?

Tropical Fish Co uses a mature, filtered 20-litre aquarium as a cautious starting policy for a small group, above OATA’s general 10-litre screen for small freshwater shrimp. Plan more space when fish or other livestock share the aquarium.

How many of this shrimp should I keep together?

OATA’s freshwater shrimp guidance says social shrimp should be kept in groups of at least five. Build the group only where mature filtration, grazing area and stable water can support it.

Is Carbon Rili Shrimp suitable for beginners?

Carbon Rili Shrimp has an intermediate store care rating because it needs a mature biological filter, zero measured ammonia and nitrite, stable water, established grazing surfaces and a protected filter inlet.

What does this shrimp eat?

Neocaridina davidi is omnivorous. Provide an appropriate complete shrimp food alongside biofilm and natural grazing; OATA advises feeding freshwater shrimp two or three times a week and allowing at least 30 minutes before removing recurring excess.

What temperature and pH does it need?

OATA’s broad freshwater-shrimp guidance gives 17–27°C, pH 6.5–8.0 and 4–18°dH, not a species-specific optimum. Keep ammonia and nitrite at zero mg per litre and avoid abrupt changes.

Is Carbon Rili Shrimp aggressive or likely to nip fins?

Carbon Rili Shrimp is peaceful. Its compatibility risk comes from fish eating the shrimp or outcompeting it for food, rather than the shrimp attacking fish or nipping fins.

Which animals can it live with?

A same-species group can share a mature, filtered aquarium. OATA says to avoid fish able to fit the shrimp in their mouth and species known to be predatory; screen every other companion for hunting behaviour, feeding competition and shared water needs.

How does Carbon Rili Shrimp arrive alive in the UK?

Someone must be present to receive the parcel. Film every delivery continuously from the sealed parcel as it is opened, showing the animal still inside the sealed bag; float the bag for 20–30 minutes before release and never pour the bag water into the aquarium.

References for identity and care

• World Register of Marine Species — accepted scientific name and family.
• Wikipedia, Neocaridina davidi — natural distribution, wild feeding, colour forms and mature length.
• Ornamental Aquatic Trade Association, freshwater shrimp and snails — water, group, aquarium, feeding, maintenance and compatibility guidance.
• Ornamental Aquatic Trade Association, freshwater aquarium setup — cycling, testing and gradual stocking.
• RSPCA aquarium environment guidance — biological filtration and waste conversion.
• Tropical Fish Co delivery policy — receipt, unboxing video, 20–30 minute floating and bag-water instructions.