Lysmata wurdemanni (Lysmata wurdemanni)

Identify the shrimp behind the trade name

Lysmata wurdemanni is a saltwater shrimp in the family Lysmatidae. The World Register of Marine Species accepts Lysmata wurdemanni (Gibbes, 1850) as the species name, so the scientific identity is the clearest way to understand which animal this page describes.

The shrimp has historically been called the peppermint shrimp in the marine aquarium trade. An encyclopaedic account of its natural history explains an important limitation of that common name: genetic and morphological revisions found that many shrimp previously labelled L. wurdemanni belong to distinct species, including Lysmata boggessi and Lysmata rathbunae. Use the binomial rather than the trade name alone when comparing identities.

This shrimp suits a keeper who already has a mature marine filter, can test saltwater parameters and is prepared to screen every proposed tank mate for predation risk. Its exoskeleton, moulting cycle and sensitivity to ammonia and nitrite make water quality, rockwork and cautious stocking more important than decorative complexity. You can compare its role with other animals in our marine invertebrates collection, but assess every addition on its own behaviour and care needs.

Know what one purchase means

One purchase supplies one animal.

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

Use the gallery as an identification aid

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.

Plan the aquarium around water quality and shelter

OATA’s marine-crustacean guidance gives 24–26°C, pH 7.9–8.3 and salinity 1.023–1.026 for the wider group. These are broad group targets rather than a species-specific optimum. Use them as the routine starting range while also meeting any narrower requirements imposed by more sensitive animals in a reef aquarium.

For smaller crab and shrimp species, OATA recommends an aquarium of at least 40 litres. Use at least 40 litres as the closest planning baseline, then increase space when the wider community, aquascape or livestock load requires it. A nominal volume does not compensate for an immature filter, crowding or poor water movement.

Reserve useful space, not just water volume

Include live or artificial rock because it creates grazing surfaces and hiding places. Freshly moulted crustaceans often hide while the new exoskeleton hardens, which may take a couple of days. Arrange enough sheltered areas that the shrimp can withdraw without losing access to the filtered part of the aquarium.

A filter is essential. Suitable marine filtration can use live rock with sufficient water flow, an internal or external filter, or a sump-based filter. A protein skimmer can also help by removing dissolved organic waste before it breaks down. Choose the method according to the complete aquarium, but make biological filtration and unobstructed flow non-negotiable.

Before choosing this shrimp, make three decisions in order: confirm that the filter is mature, confirm that the water falls within the working targets and confirm that existing animals are unlikely to prey on a shrimp. Only then should colour, behaviour or an interest in Aiptasia influence the purchase.

Build biological filtration before adding the shrimp

A mature filter contains beneficial bacteria able to process the waste created by the aquarium’s livestock and feeding. The RSPCA’s aquarium filtration guidance explains the sequence: toxic ammonia is converted to nitrite, which is also toxic, and then to the safer end product nitrate. The filter must be established and operating before the shrimp enters the aquarium.

Choose a filtration route that fits the aquarium

• Live rock with sufficient flow: use it as part of the biological filtration while preserving open paths for water movement.
• Internal or external filter: keep the intake, media and flow path free from blockage so water continues to pass through the biological media.
• Sump-based filtration: maintain the return and media sections as working parts of the same biological system.
• Protein skimmer: use one where appropriate to remove dissolved organic waste before that waste breaks down further.

Filter choice does not replace testing. Confirm zero mg per litre ammonia and zero mg per litre nitrite before adding the shrimp. Continue testing after additions because extra livestock and feeding increase the load placed on the bacterial population.

Increase the biological load slowly

Add livestock gradually rather than treating spare water volume as spare biological capacity. Beneficial bacteria need to increase as the aquarium population and feeding load rise. Adding too many animals too quickly can create new tank syndrome, allowing ammonia or nitrite to reach unhealthy levels.

Use a simple checkpoint after every addition: test ammonia and nitrite, inspect the filter for normal flow and check whether uneaten food remains. If either nitrogen reading rises above zero, pause further additions and review filtration, feeding and maintenance before placing more demand on the aquarium.

Keep filtration decisions separate from appearance. Clear water can still contain dissolved ammonia, nitrite or nitrate, while suspended particles do not by themselves measure biological performance. Base the decision to add this shrimp on test results, established filtration and stable operation rather than sight alone.

Hold the marine water values within their working ranges

Run the aquarium at 24–26°C, salinity 1.023–1.026 and pH 7.9–8.3. Keep carbonate hardness at 8–12°dKH, calcium at 380–450 ppm and magnesium at 1,250–1,350 ppm. Ammonia and nitrite must remain at zero mg per litre, while nitrate must not exceed 50 mg per litre.

Measure the values that drive a decision

Record results rather than relying on memory. A short log of temperature, salinity, pH, ammonia, nitrite and nitrate shows whether a reading is isolated or part of a developing pattern. Add carbonate hardness, calcium and magnesium to that routine so the complete marine chemistry remains within its target range.

Reef aquariums may contain more sensitive animals that require adjusted or narrower parameters. In that situation, use the range that safely accommodates the most sensitive resident while keeping every value within the shrimp’s working marine range. Compatibility includes shared water requirements as well as direct behaviour.

Act before a limit becomes a health problem

Marine crustaceans can be stressed by even small amounts of ammonia and nitrite. Do not wait for visible changes before responding to a non-zero result. Stop increasing the livestock load, check that the filter is flowing freely, remove the cause of excess waste and resume additions only after ammonia and nitrite return to zero.

Keep nitrate below its stated maximum rather than treating 50 mg per litre as a target. Weekly partial water changes, controlled supplementary feeding and removal of accumulated solid waste work together to prevent deterioration. The maintenance section below gives the routine for carrying out those tasks without damaging the biological filter.

Feed a varied diet without overloading the filter

Marine crustaceans have varied dietary requirements. Most members of the group are omnivorous and consume algae, detritus and small meaty items, so use a mixed feeding plan rather than relying on one food. Suitable group choices include nori algae sheets, small frozen foods such as brine shrimp and pellets.

OATA also notes that peppermint shrimp identified as Lysmata wurdemanni consume unwanted Aiptasia anemones. Treat that behaviour as one possible part of what the shrimp finds in an aquarium, not as a complete feeding plan or a guaranteed method of clearing every Aiptasia. Continue to offer varied supplementary food whether Aiptasia is present or absent.

Let natural grazing guide supplementary feeding

Many crustaceans graze through the day, so a fixed number of meals does not suit every aquarium. Base supplementary feeding on the natural food present, the shrimp’s feeding response and the amount left after a feed. The goal is to provide variety without leaving excess food to decay.

• If nori is consumed fully: continue offering it as part of the rotation, especially where aquarium algae are limited.
• If small frozen food is taken promptly: retain it as the meaty part of the varied diet.
• If pellets remain uneaten: remove the leftovers and reduce the next supplementary feed.
• If food repeatedly accumulates: review the portion before increasing frequency or adding another food.
• If Aiptasia remains: continue normal feeding and manage expectations rather than withholding food from the shrimp.

Uneaten food breaks down and releases waste into the water. That creates extra work for the biological filter and can contribute to rising ammonia, nitrite or nitrate. Check the feeding area after each supplementary feed and use the next portion to correct any consistent surplus.

Do not assume visible grazing means supplementary nutrition is never needed. The amount and type of natural food vary between aquariums, and animals sold for a grazing role still require an appropriate diet when they consume the material they were introduced to eat. A rotation of algae-based and small meaty foods gives a more practical plan than dependence on a single aquarium pest.

Provide rockwork for grazing and safe moulting

Crustaceans have a segmented body protected by a hard exterior called an exoskeleton. Growth requires them to shed that exterior. An empty shell in the aquarium can therefore be a normal moult rather than the body of the shrimp.

After shedding, the replacement exoskeleton may take a couple of days to harden. The shrimp will often hide during this period, making secure shelter a functional part of its care rather than an optional decoration. Live or artificial rock is essential because it provides both grazing opportunities and places where a freshly moulted animal can withdraw.

Read a moult in the right order

1. Inspect the empty shell: recognise that a complete shrimp-shaped casing may be a shed exoskeleton.
2. Look for the animal: check sheltered areas visually without assuming that temporary hiding means the shrimp has been lost.
3. Observe movement and condition: once the shrimp reappears, look for coordinated walking or swimming and a complete exoskeleton.
4. Recheck water quality: confirm zero ammonia and nitrite and keep the remaining marine values within range.

Normal hiding after a moult must still be distinguished from a health change. Difficulty moulting, incomplete shedding, a prolonged soft-shell condition or a marked change in moulting frequency belongs on the health-warning checklist. Combine what you see with test results instead of judging the empty shell alone.

Make shelter part of the stocking plan

Reserve rockwork for the shrimp before introducing it. Do not count a crowded pile that is already occupied by territorial or predatory animals as dependable shelter. The aquarium should offer grazing surfaces and withdrawal areas while preserving sufficient water flow for the filtration system.

When considering additional livestock, check that sheltered areas remain accessible and that new animals will not remove the shrimp’s opportunity to hide. This is particularly important around a moult, when the new exoskeleton has not yet hardened. Space, compatibility and shelter therefore need to be assessed together rather than as separate decorations and livestock choices.

Complete the weekly maintenance without harming the filter

Carry out a partial water change of 25% at least once every week. Use a siphon where the substrate allows it so solid waste does not continue breaking down in the aquarium. Test the water as part of the same routine, covering ammonia, nitrite, nitrate, pH and the remaining marine parameters used for this setup.

Protect the biological bacteria during cleaning

Check and clean filters regularly to prevent blockages, but do not run the filter under the tap. Chlorine or chloramine can kill part of the beneficial bacterial population established in the media. Instead, rinse the media lightly in aquarium water removed during the partial water change.

A light rinse is different from making every piece of media look new. The purpose is to remove obstructive debris while retaining as much of the bacterial population as possible. Restore the filter promptly and confirm normal flow after cleaning.

Use one repeatable weekly sequence

1. Record temperature, salinity, pH, ammonia, nitrite, nitrate, carbonate hardness, calcium and magnesium.
2. Inspect the shrimp for coordinated movement, normal colour, intact appendages and interest in food.
3. Remove accumulated solid waste with a siphon where practical.
4. Change 25% of the water.
5. Rinse filter media lightly in the removed aquarium water when cleaning is due.
6. Restore the filter and check that water flow is unobstructed.
7. Clean the protein skimmer regularly where one is used so it continues working effectively.

During the first four weekly maintenance cycles after adding the shrimp, compare each set of readings with the previous one. This creates an early warning if the added feeding and livestock load are pushing nitrate upwards or causing ammonia or nitrite to appear.

If a filter blockage, excess food or accumulated waste is found, correct that cause before adding more livestock. Maintenance should preserve biological capacity and remove waste; it should not create a second disruption by running the filter under the tap.

Acclimatise slowly and keep transport water out

Prepare the aquarium before the delivery window. Confirm that someone can receive the parcel, that the filter is running and that ammonia and nitrite are both zero mg per litre. Check temperature, salinity and pH against the aquarium targets before opening the bag.

Follow our delivery and Live Arrival Guarantee policy for the current arrival procedure and claim requirements. The core acclimatisation instruction is to float the closed bag for 20–30 minutes before releasing the shrimp. Never pour the bag water into the aquarium.

Use this arrival sequence

1. Receive the parcel in person: live animals must not be left unattended.
2. Inspect before release: observe the shrimp and follow the current policy if a Live Arrival Guarantee claim may be needed.
3. Float for 20–30 minutes: keep to the store’s stated timing rather than substituting a different float period.
4. Release without bag water: transfer the shrimp while keeping the transport water out of the aquarium.
5. Observe the introduction: watch walking, swimming, hiding and interactions with established livestock.

Do not use acclimatisation to compensate for an unsuitable aquarium. If ammonia or nitrite is detectable, the biological filter requires attention before another animal is introduced. If the proposed tank mates have not been screened for predation, complete that decision before opening the bag.

Add the shrimp as one controlled increase in livestock load. Additional animals and extra feeding should follow gradually so the filter’s beneficial bacteria can respond to the higher waste input. Test after the addition rather than assuming that previously good results will remain unchanged.

Hiding soon after a moult can be part of normal crustacean biology, but a new arrival still needs observation. Use the specific warning signs in the health section—loss of coordination, unusual movement, damage, marked colour change or feeding refusal—to decide whether a response is needed.

Respond to changes in movement, colour and condition

Observe the shrimp often enough to recognise a change from its usual pattern. Marine crustaceans vary in appearance and behaviour, so the decision rests on change over time rather than one isolated pose. Pair visual observation with water tests because ammonia and nitrite can cause serious stress even in small amounts.

Use a practical warning-sign checklist

Moulting needs its own interpretation. An empty exoskeleton and temporary hiding can be normal, while incomplete shedding, difficulty moulting, prolonged softness or a changed moulting pattern are warning signs. Locate and observe the shrimp rather than treating the shell alone as the diagnosis.

Correct the environment before guessing at treatment

If ammonia or nitrite is above zero, pause further livestock additions and inspect the filter, feeding level and accumulated waste. If food remains after feeds, remove the surplus and reduce the next portion. If another animal is pursuing or attempting to eat the shrimp, treat compatibility as the immediate problem.

Do not apply a disease treatment based only on a general symptom. Record the test results and visible change, then contact us for help assessing persistent health changes. Clear observations—movement, feeding, colour, moult condition and water readings—make that assessment more useful than a broad description that the shrimp looks unwell.

Avoid fish that are likely to prey on shrimp

Marine crustaceans generally mix with fish considered reef-safe, while fish that are not reef-safe are likely to prey on them and should not be kept with them. Avoid any fish whose normal aquarium behaviour places shrimp at risk of predation.

A reef-safe description is a starting screen rather than a guarantee for every individual combination. Compatibility varies, and a label applied to a species cannot predict every interaction in a particular aquascape. Review the proposed fish, the existing community and the shrimp’s access to rockwork before deciding.

Apply the screen before purchase

• First, classify the proposed fish: if it is not considered reef-safe and is likely to prey on marine crustaceans, do not combine it with this shrimp.
• Second, examine the current aquarium: check whether the shrimp will have genuine hiding areas rather than rockwork already controlled by other animals.
• Third, consider the introduction: add livestock gradually so behaviour and water quality can be observed after each change.
• Finally, keep uncertainty explicit: where a proposed combination has unclear behaviour around shrimp, delay the addition until it has been assessed.

Do not turn a broad community description into a universal tank-mate list. A fish community can be peaceful towards other fish while still presenting a predation risk to a crustacean. The relevant question is whether each animal is suitable around shrimp, not simply whether it is sold as a community fish.

For a stocking and compatibility assessment, contact us with the identities of the proposed tank mates, aquarium volume and existing rockwork. That is more useful than choosing by colour, general temperament or the word “reef” alone.

Assess other crustaceans and slow-moving neighbours carefully

Marine crustaceans differ widely in compatibility. Some scavenging lobsters and crabs are opportunistic and may prey on slow-moving aquarium inhabitants, so do not assume that sharing the same animal group makes two invertebrates suitable companions.

Separate direct behaviour from shared water needs

Begin with direct risk: consider whether a crab, lobster or other proposed resident is known for opportunistic feeding. Then compare the shared environment. Every resident must fit the same temperature, salinity, pH and water-quality plan, with the narrower requirements of sensitive reef animals governing the final target.

Rockwork helps by providing grazing areas and shelter for a newly moulted shrimp, but shelter does not make a predatory combination safe. Avoid a known predation risk rather than trying to solve it by adding more décor.

Continue observing after introduction. A change in hiding, feeding response, movement or physical condition may signal that the social environment needs attention, especially if damage appears on limbs, antennae, eyes or the exoskeleton.

Compatibility is also affected by stocking pace. Every new animal and the extra food it receives increase the load on the filter. A behaviourally suitable combination can still fail if several additions push ammonia or nitrite above zero, so test the water as well as watching interactions.

Add each animal as a separate stocking decision

Treat one shrimp as a complete, individually assessed addition. One purchase supplies one animal; it does not imply a group. If you plan to keep more than one, repeat the compatibility, shelter and filtration checks for every addition rather than assuming the first successful introduction settles the decision.

Use a one-addition checkpoint

1. Confirm zero mg per litre ammonia and zero mg per litre nitrite.
2. Confirm temperature, salinity and pH remain within the working marine ranges.
3. Check that rockwork still offers grazing surfaces and hiding areas.
4. Screen every established fish for predation risk around shrimp.
5. Review opportunistic crabs, lobsters and other scavenging crustaceans carefully.
6. Add livestock slowly and observe both behaviour and water quality before the next addition.

This approach answers the practical group-planning question without forcing a social arrangement onto the shrimp. Begin with the number you can house, feed and observe responsibly, then make any further addition a fresh decision based on the aquarium’s response.

Watch the biological load as closely as the animals. More livestock generally means more feeding and more waste, requiring the beneficial bacteria in the filter to increase. If ammonia or nitrite appears, stop adding animals and correct filtration, feeding or maintenance before continuing.

Food distribution also changes when more scavenging animals share an aquarium. Continue offering a varied diet while checking for uneaten material. Adding extra food indiscriminately can allow leftovers to decay, so judge each supplementary feed by what is consumed and what remains.

Finally, preserve access to shelter. A freshly moulted shrimp may hide for a couple of days while its exoskeleton hardens. Additional livestock must not remove every usable hiding place or introduce an avoidable predation risk during that vulnerable period.

Answer the key questions before choosing this shrimp

What is Lysmata wurdemanni?

It is an accepted saltwater shrimp species in the family Lysmatidae, historically called the peppermint shrimp in the marine aquarium trade. Taxonomic revisions mean that this trade name has also been used for several distinct western Atlantic shrimp.

How many Lysmata wurdemanni does one purchase supply?

One purchase supplies one animal.

What should be checked before adding Lysmata wurdemanni?

Confirm that the marine filter is mature and running, ammonia and nitrite are zero mg per litre, the water is within its working ranges and suitable rockwork is in place before adding the shrimp.

What aquarium setup does this shrimp need?

Lysmata wurdemanni needs a mature, filtered marine aquarium with live or artificial rock for grazing and hiding. Use OATA’s at-least-40-litre planning baseline for smaller crabs and shrimp, then allow extra room for the complete community.

Should Lysmata wurdemanni be kept alone or in a group?

Treat one animal as a complete, individually assessed addition. When considering more than one, add livestock slowly, provide rockwork and hiding places, and recheck water quality and compatibility after each addition.

What water parameters does this animal need?

OATA’s marine-crustacean guidance gives 24–26°C, salinity 1.023–1.026 and pH 7.9–8.3. Keep ammonia and nitrite at zero mg per litre and nitrate below the stated maximum of 50 mg per litre.

What should it eat?

Offer a varied marine-crustacean diet using nori, small frozen foods such as brine shrimp and pellets. Adjust supplementary feeding to natural grazing and remove uneaten food; do not depend on Aiptasia as the complete diet.

How should it be acclimatised?

Start filming before opening the sealed parcel and continue in one take through opening it and showing the shrimp inside the sealed bag. Then float the bag for 20–30 minutes before release and never pour the bag water into the aquarium.

Which tank mates suit this animal?

Screen every proposed tank mate individually. Avoid fish that are not reef-safe and are likely to prey on marine crustaceans; fish considered reef-safe still require an individual compatibility check, and opportunistic crabs or lobsters need caution.

Check the public reference list

• World Register of Marine Species — accepted scientific name and family.
• Lysmata wurdemanni encyclopaedic account — historical trade name and taxonomic context.
• OATA marine crustacean guidance — water, aquarium, feeding, moulting, maintenance and compatibility.
• RSPCA aquarium guidance — biological filtration and waste processing.