Blue Velvet Shrimp (Neocaridina davidi)

Recognise the blue colour form

Blue Velvet Shrimp is a selectively bred blue colour form of Neocaridina davidi, a freshwater shrimp in the family Atyidae from Taiwan, eastern China, the Korean Peninsula and Vietnam that reaches 4 cm. The accepted species name is confirmed by the World Register of Marine Species. Older aquarium labels may use Neocaridina heteropoda. This is an intermediate-care choice for a keeper prepared to mature the filter, test the water, protect equipment inlets and manage food carefully.

The blue appearance is an aquarium colour form rather than the species’ wild-type colour. Wikipedia’s natural-history summary describes wild N. davidi as mottled brown and records selectively bred forms in blue and several other colours. It also describes the species as omnivorous and naturally associated with lakes, ponds, rivers and streams. Treat those places as the species’ natural distribution and plan the aquarium around measured captive conditions.

Its small size does not remove the need for stable water or enough space for a social group. The peaceful shrimp spends much of its time using surfaces for grazing and cover, so the quality of the aquarium matters more than fitting it into the smallest possible volume.

Use the cherry shrimp collection to compare related colour forms. If retaining one named blue line matters, plan a separate, single-line aquarium rather than mixing colour forms.

Choose the dispatch size from the live selector

One purchase supplies one animal. Use the live size selector to choose between the labels “1 - 1,5 cm” and “2 - 2.5 cm”, then set the purchase quantity according to the number needed for your planned group.

The size you select is the size supplied, not the adult size. These measurements describe the shrimp at dispatch. Plan for an adult size of 4 cm; Wikipedia describes mature shrimp as approximately 3–4 cm. Allow for that adult size when considering feeding area, filter protection, companions and the possible survival of juveniles.

Sex is guaranteed only when the selected option explicitly states male or female. This Blue Velvet Shrimp listing has no sex-guaranteed option. Do not plan a sex ratio, breeding outcome or colony-growth timetable around an unsexed purchase.

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. Lighting, background, viewing angle and the shrimp’s condition can all affect how blue colour appears, so use the gallery to recognise the general form rather than as a promise of an identical shade.

Start with the decisive care numbers

Begin with a mature, filtered aquarium and measured water. Tropical Fish Co uses 20 litres as a cautious starting policy for a small group, while OATA’s freshwater shrimp and snail guidance gives at least 10 litres for a group of small shrimp. The larger 20-litre starting point gives more room for equipment, grazing surfaces and stable conditions; plan larger when fish or other livestock share the aquarium.

OATA gives 17–27°C, pH 6.5–8.0 and general hardness of 4–18°dH for the freshwater shrimp and snail group; these are broad planning ranges, not a species-specific optimum for N. davidi. Ammonia and nitrite should measure zero, while nitrate should not exceed 20 mg per litre above the normal tap-water level.

Shrimp are generally social, and OATA advises keeping social shrimp in groups of at least five. That figure describes the intended total group, not a pack size or a shrimp-per-litre formula. Count any compatible shrimp already present, choose the purchase quantity accordingly and leave capacity for every other animal in the aquarium.

Read our complete Cherry Shrimp Care Guide when planning filtration, grazing surfaces, food, medicines and long-term population capacity.

Match measured water and keep changes gradual

Choose stable aquarium conditions within 17–27°C, pH 6.5–8.0 and 4–18°dH, then check that every intended companion shares the chosen values. Avoid chasing a midpoint simply because it sits in the centre of each range. Stability and a gradual transition from the shrimp’s starting conditions are the practical priorities.

Measure before changing anything

• Temperature: measure the aquarium rather than judging it from the room, season or postcode.
• pH and hardness: test the aquarium because substrate, rock, top-ups and treatment can alter tap-water values.
• Ammonia and nitrite: both should be zero before shrimp are introduced.
• Nitrate: keep it from exceeding 20 mg per litre above the normal tap-water level.

Use a heater only when the measured room and aquarium temperature cannot remain stable within the range chosen for the full community. A cool room may require a correctly sized, guarded and thermostatically controlled heater. A warm room needs an overheating plan rather than extra heat.

Hardness labels such as “soft” or “hard” are not precise enough for this decision. Test in degrees of general hardness and compare the result with the 4–18°dH planning range. Water from an ion-exchange softener should not automatically be treated as suitable because that process replaces calcium and magnesium with sodium.

Our water chemistry guide explains what each measurement means. When you have actual figures, use the water matcher to compare the aquarium with the stated range.

Prove the filter is mature with water tests

A mature aquarium is defined by functioning biological filtration and measured water, not by waiting a fixed number of weeks. The filter must process the planned livestock load while ammonia and nitrite remain at zero. Add shrimp only after testing shows that condition is being maintained.

The RSPCA’s aquarium welfare guidance explains why filtration matters: beneficial bacteria convert toxic ammonia first to nitrite and then to the safer nitrate. OATA’s freshwater aquarium setup advice also supports cycling, regular testing and gradual stocking.

Use this readiness check

1. Run an appropriately sized filter continuously and make sure water can pass through it normally.
2. Test ammonia and nitrite rather than relying on clear-looking water.
3. Confirm both readings are zero before adding the group.
4. Check that temperature, pH and hardness are stable within the chosen range.
5. Add livestock gradually so the bacterial population can adjust as waste and feeding increase.

A newly installed filter is not mature merely because it is running, and old-looking water is not proof of safe biological filtration. Equally, a mature filter can be damaged by chlorine, chloramine, blockages or over-cleaning. Preserve its bacteria during routine maintenance and continue testing after livestock or feeding increases.

Start with our guide to preparing and maturing a shrimp aquarium if the tank is still being set up. Give the filter enough capacity for the entire adult community, not only the shrimp being added today.

Build cover, grazing space and protected equipment

Use aquarium gravel or sand with plants and aquarium-safe structure. Live plants are ideal because they add cover and usable surfaces, while suitable artificial plants and ornaments can provide shelter when live plants are not used. Wood, rock and other structured surfaces also increase the area the shrimp can inspect and graze.

Arrange the aquarium for shrimp access

• Provide established surfaces carrying natural grazing growth.
• Create sheltered areas that remain usable after plants are trimmed.
• Keep feeding and grazing areas accessible to the whole group.
• Leave enough open space to inspect the shrimp and maintain equipment.
• Use a secure cover without obstructing ventilation or cables.

Protect any filter intake that could trap a small shrimp or newly hatched juvenile. A suitable fine guard or sponge keeps the intake working while reducing that risk. Check the guard for restricted flow whenever equipment is inspected, because protection is useful only while water can still move through the filter properly.

Plan from the aquarium’s real water volume and usable footprint after substrate, wood, rock and equipment are installed. A nominal 20-litre tank does not contain 20 litres of swimming and grazing space once displaced volume is considered. The 20-litre house policy is therefore a starting point for a small group, not permission to fill every remaining area with livestock.

Established biofilm is valuable grazing support, but an old appearance does not prove safe water and biofilm is not a complete feeding plan. Combine mature surfaces with zero ammonia and nitrite, appropriate food and regular maintenance.

Feed the grazers without fouling the water

Blue Velvet Shrimp are omnivores and will graze biofilm, algae and soft growth from aquarium surfaces. Grazing supports their normal feeding behaviour, but algae alone is not a complete feeding plan. Use an appropriate complete sinking shrimp food as the nutritional base and follow the manufacturer’s directions for the product and group.

Set portions by observation

1. Place food where the shrimp can reach it without being displaced by faster companions.
2. Allow at least 30 minutes for shrimp to feed before judging whether the portion was accessible.
3. Check whether food is repeatedly left to break down.
4. Remove recurring excess and reduce the next portion.
5. Review water-test trends when feeding or group size changes.

Do not use a permanent feeding amount for every aquarium. The correct portion depends on the complete food, the number and size of shrimp, the grazing already present, competition from companions and whether juveniles are surviving. A manufacturer’s starting direction combined with observation is more useful than copying a quantity from a different tank.

Overfeeding creates two linked problems: uneaten food breaks down into waste, and additional feeding increases the load placed on the biological filter. If ammonia or nitrite appears, stop treating the issue as a request for more food and address water quality and filtration immediately.

Colour alone is not a reliable feeding gauge. Lighting, background, inherited colour, stress and health can all alter appearance, so do not automatically add colour food when a shrimp looks paler. Assess behaviour, feeding access, water measurements and the group as a whole.

Maintain the aquarium every week

At least once every week, carry out a partial water change of 25%. Treat replacement tap water with a conditioner that removes chlorine or chloramine before it enters the aquarium, and avoid abrupt differences in temperature or chemistry.

Test ammonia and nitrite at least weekly and keep both at zero. Review nitrate against the limit of no more than 20 mg per litre above the normal tap-water level. Record the readings so a trend is visible before it becomes a larger problem.

Protect the biological filter

• Check the filter for blockages and reduced flow.
• When cleaning is needed, rinse media lightly in aquarium water removed during the partial water change.
• Do not rinse biological media under the tap because chlorine or chloramine may kill beneficial bacteria.
• Avoid replacing or deep-cleaning all biological media at once.

Use a siphon where practical to remove solid waste from accessible substrate without stripping every grazing surface bare. The aim is to control accumulating waste while retaining useful cover and established surfaces. Inspect protected intakes after cleaning and make sure guards have been refitted securely.

During the first month after adding shrimp, keep a simple weekly record of temperature, ammonia, nitrite, nitrate, pH and hardness. Note feeding changes, maintenance and additions alongside the readings. If a result changes, this sequence helps identify what happened without altering several parts of the aquarium at once.

Stable husbandry comes from repeating these checks, not from assuming a mature aquarium remains safe indefinitely. Population growth, new companions, extra food and blocked equipment can all increase demand on the filter.

Acclimatise slowly with the store method

Prepare the aquarium before the delivery window. Following OATA’s care guidance, confirm that ammonia and nitrite are zero, temperature is stable within the chosen range and the filter is operating normally.

Follow the current delivery and Live Arrival Guarantee policy. Someone must be present to receive the parcel so live animals are not left unattended.

Use this arrival sequence

1. Receive the parcel in person.
2. Start filming before opening it, with the parcel still sealed and the outer box visible.
3. Film the parcel being opened in one continuous take and show the shrimp still inside the sealed bag before anything is disturbed.
4. Float the bag for 20–30 minutes.
5. Release the shrimp without pouring the bag water into the aquarium.

Keep the introduction gradual and condition-led. Do not make a rapid water-chemistry correction while the animal is arriving. When the aquarium sits outside the stated range or has detectable ammonia or nitrite, resolve that problem before livestock is introduced.

Add numbers slowly when building a group. Every extra animal and every increase in feeding requires the filter’s beneficial bacteria to handle more waste. Rapid stocking can cause new tank syndrome, in which ammonia or nitrite rises because the biological filter cannot yet process the added load.

Respond to health changes with measurements

Learn the group’s normal activity, colour, hiding pattern and response to food. Changes in swimming, increased inactivity, restlessness, unusual hiding, altered breathing effort, reduced feeding, abnormal swelling, lesions, white spots, damaged exoskeleton or missing appendages all justify a closer check.

An empty exoskeleton can be a normal result of moulting and may resemble a dead shrimp. Hiding may also occur around moulting, but neither a shed shell nor hiding alone identifies the cause of a problem. Compare the affected animal with the rest of the group and measure the aquarium before choosing a response.

Check in this order

1. Measure temperature, ammonia and nitrite immediately.
2. Review nitrate, pH and hardness alongside recent readings.
3. Check filter flow, aeration, heating and recent maintenance.
4. Review recent livestock, plants, décor, food, sprays and treatments.
5. Record clear changes and seek help when signs persist or are severe.

Contact us about a health change with the measurements and observations ready. Clear values and a short sequence of recent events are more useful than changing food, water chemistry and medicines simultaneously.

Freshwater shrimp are highly sensitive to copper. Do not add a treatment unless its exact current label and every invertebrate warning confirm that it is suitable for shrimp. Identify the problem before treating, and use suitably qualified aquatic or veterinary help when medicine compatibility remains unclear.

Screen every fish for predation risk

Blue Velvet Shrimp are peaceful, but that does not make every peaceful community fish safe. OATA advises avoiding fish that can fit shrimp in their mouth and species known to be predatory. Newly hatched juveniles are smaller than adults, so an aquarium that retains adult shrimp may still lose shrimplets.

No fish is guaranteed shrimplet-safe. Judge the complete adult behaviour and body size of the intended companion rather than its shop size, reputation or response during a short observation. Compatibility also requires overlap in temperature and water chemistry.

Apply the full screening rule

• Mouth size: could the adult fish swallow an adult shrimp or a juvenile?
• Feeding behaviour: will fast companions prevent shrimp reaching food?
• Hunting and territory: does the species actively search cover or defend the bottom area?
• Water overlap: can all animals share one stable temperature, pH and hardness range?
• Cover: will useful shelter remain after plants are trimmed and maintenance is completed?
• Moulting: is there shelter for a shrimp when its new exoskeleton is vulnerable?

A shrimp-only aquarium removes fish predation from the plan, but it does not remove risks from water quality, feeding, equipment or crowding. Choose it when juvenile survival or preservation of one colour line is the priority, while keeping the same filtration and maintenance standards.

Choose between display and colony goals

Decide what success means before adding Blue Velvet Shrimp. A mixed display, a single-colour group and a juvenile-focused shrimp aquarium create different risks even when the water values overlap.

For a mixed display

Assess every fish at adult size for mouth size, hunting, territory and feeding competition. Provide cover and a protected intake, then keep a separation plan ready if behaviour changes. Adult coexistence is not a promise that juveniles will survive.

For a single blue line

Use one colour line if preserving the named appearance matters. Provide mature grazing surfaces, complete food and dense usable cover, but do not treat an unsexed starting group as a guaranteed breeding group.

For maximum juvenile survival

A shrimp-only aquarium removes fish predation, while protected filter intakes reduce an equipment risk. Mature filtration, appropriate feeding and stable water remain essential, and surviving juveniles must be included in future capacity decisions.

For an established community

Calculate from the real aquarium volume after décor and equipment, then include every adult companion and possible population growth. OATA recommends a larger aquarium when small shrimp are kept with fish, so do not apply the 20-litre small-group policy unchanged to a full community.

Contact us with the aquarium volume, measured water values, current livestock and intended group size for a stocking and compatibility assessment. Those details allow a specific decision without presenting any species as a universal tank mate.

Answer common Blue Velvet Shrimp questions

How big does Blue Velvet Shrimp get?

Blue Velvet Shrimp (Neocaridina davidi) reaches 4 cm. Plan the aquarium, feeding area, equipment protection and companions around that adult size rather than the dispatch measurement.

What size aquarium does Blue Velvet Shrimp need?

Start a small group in a mature, filtered aquarium from 20 litres under Tropical Fish Co’s cautious planning policy. OATA gives at least 10 litres for a group of small shrimp, while the larger starting point provides more headroom for equipment, grazing surfaces and water stability.

How many Blue Velvet Shrimp should I keep together?

Keep a social group of at least five under OATA’s freshwater shrimp guidance. This is the total group size, not a pack size or a permanent shrimp-per-litre formula.

Is Neocaridina davidi suitable for beginners?

Neocaridina davidi is an intermediate-care choice under the Tropical Fish Co assessment. It suits a keeper prepared to maintain mature filtration, measure water, protect the filter intake and control feeding.

What does Blue Velvet Shrimp eat?

Blue Velvet Shrimp is omnivorous and grazes biofilm, algae and soft growth. Provide an appropriate complete sinking shrimp food as the nutritional base, follow its directions and remove recurring excess.

What temperature and pH does this shrimp need?

OATA’s freshwater shrimp guidance gives 17–27°C, pH 6.5–8.0 and 4–18°dH as group planning ranges, not a species-specific optimum. Keep ammonia and nitrite at zero and make chemistry changes gradually.

Is Blue Velvet Shrimp aggressive or likely to nip fins?

Blue Velvet Shrimp is assessed as peaceful. Screen fish for adult mouth size, hunting, territorial behaviour and feeding competition because a peaceful shrimp can still be eaten or prevented from reaching food.

Which animals can Neocaridina davidi live with?

A shrimp-only aquarium removes fish predation, while fish may be considered only after screening adult mouth size, predatory behaviour, feeding competition, water overlap and cover. Avoid fish able to fit shrimp in their mouth and species known to be predatory; no fish is guaranteed shrimplet-safe.

How does this shrimp arrive alive in the UK?

Film every delivery continuously from the sealed parcel as it is opened, showing the shrimp still inside the sealed bag before anything is disturbed. Someone must be present to receive it; float the bag for 20–30 minutes, then release the shrimp without pouring the bag water into the aquarium.

Consult the care references

• World Register of Marine Species: accepted scientific name, authorship and family placement.
• Wikipedia, Neocaridina davidi: natural distribution, wild feeding mode, colour forms and approximate mature length.
• Ornamental Aquatic Trade Association, freshwater shrimp and snails: UK group guidance for water, social grouping, aquarium setup, feeding, maintenance and compatibility.
• RSPCA aquarium environment guidance: the role of biological filtration in processing ammonia and nitrite.
• Ornamental Aquatic Trade Association, freshwater aquarium setup: cycling, testing and gradual stocking principles.