Fire Shrimp (Lysmata debelius)

Fire Shrimp at a glance

The Fire Shrimp, Lysmata debelius, is a marine cleaner shrimp from the Indo-Pacific that is also sold as the blood shrimp or the scarlet cleaner shrimp. Each purchase is one live shrimp in the size you pick, M or the larger L/XL. The most important condition is the aquarium it goes into: an established salt-water system whose ammonia and nitrite already read zero, with rock to shelter in and a keeper who tests and changes water every week.

The care tab walks through setting up the aquarium, water values and testing, moulting, feeding, arrival day and the weekly routine. The compatibility tab explains which neighbours make sense for a shrimp and which put it at risk, and the FAQ answers the questions keepers ask most often before they buy.

Names, identity and the size you receive

One animal, several names

Fire shrimp, blood shrimp and scarlet cleaner shrimp are all trade names for the same animal, and each one points to the deep red colouring that makes it so easy to recognise. Common names travel loosely between shops and countries, so the scientific name is the dependable label when you compare advice. The World Register of Marine Species lists Lysmata debelius Bruce, 1983 as an accepted species in the family Lysmatidae, within the decapods, the ten-legged crustaceans that also include crabs and lobsters. Wikipedia's species summary describes it as a cleaner shrimp indigenous to the Indo-Pacific and popular in the aquarium trade.

What each purchase brings

Two sizes are offered on this page, M and L/XL, and one purchase supplies one shrimp of the size you choose. The size you select is the size supplied, not the adult size. Like other crustaceans, a Fire Shrimp grows by moulting: it sheds its hard outer skeleton and forms a larger one, so growth happens in steps. The moulting section in the care tab explains what that looks like in the aquarium.

Choosing between M and L/XL

Both sizes are the same species and need exactly the same aquarium, water and food. The label tells you how big the shrimp is when it leaves us, and L/XL is the larger of the two. A shrimp bought at M simply has more moults ahead of it in your aquarium, while an L/XL shrimp is further along the same path. Choose the size that suits you, then plan the aquarium in exactly the same way for either.

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

About the photograph

The gallery photograph shows a deep red shrimp with white spots, long white antennae and white-tipped legs standing on pale gravel. Gallery images have been digitally enhanced to improve image quality. Natural colour, pattern, size and maturity can vary between live animals. The shrimp you receive will be an individual of the size you chose, and it may differ from the photograph in those ways.

What to expect day to day

The rockwork is the shrimp's home base in the aquarium: OATA describes rock as the place for crustaceans to graze and for a freshly moulted animal to hide. Every so often you will find an empty shell where it has moulted, and for a couple of days afterwards it will often stay out of sight while its new exoskeleton hardens. Both are normal parts of keeping a crustacean, and knowing them in advance saves a good deal of worry.

Before you order

• The aquarium is salt water and established, and its filter has matured, with ammonia and nitrite at zero.
• Salinity, temperature and pH sit inside the ranges given in the care tab.
• There is live or artificial rock with places to hide, especially for the days after a moult.
• The fish already in the tank are reef-safe rather than species that eat crustaceans.
• Someone can be at home on the delivery day to take the parcel in and open it the same day.

Setting up the aquarium

How big an aquarium?

The Ornamental Aquatic Trade Association (OATA) advises buying an aquarium as large as is reasonably possible for marine crustaceans. Its care sheet recommends at least 40 litres for smaller species of crabs and shrimps, and says larger crustaceans need a larger aquarium, with the right size varying by species. Read that 40 litres as the smallest volume OATA gives for small crustaceans in general, not as a target for a Fire Shrimp.

A bigger body of water also gives you more room for error. A missed test, a warm spell or a little uneaten food has a smaller effect on the chemistry of a large aquarium than on a small one, and steadiness is what a shrimp needs most.

Heating and temperature

Holding the water between 24 and 26°C in a UK home normally means an aquarium heater with a thermostat, plus a thermometer you can read at a glance. Check it as part of every visit to the tank. Rooms warm up in summer and cool down overnight in winter, so look more often during hot spells or cold snaps, when the water is most likely to drift outside the range.

Filtration, flow and skimming

A filter is essential. For a marine set-up OATA lists several workable approaches: live rock with sufficient water flow, an internal or external filter, or a sump-based filter. A protein skimmer can also help, because it removes dissolved organic waste before that waste breaks down into more harmful substances.

Filtration matters because of the nitrogen cycle. As the RSPCA's guidance on aquarium environments explains, ammonia released into the water is toxic. A working biological filter grows beneficial bacteria that break it down: ammonia is converted to nitrite, which is also toxic, and then to nitrate, which is safer. Those bacteria take time to establish, which is why a new aquarium has to mature before invertebrates go in.

Rock and décor

Marine crustaceans need very little in the way of décor, but OATA describes live or artificial rock as essential. Rock gives a shrimp surfaces to graze over and, just as importantly, places for a freshly moulted animal to hide while its new shell hardens. Build the rockwork with overhangs and gaps a shrimp can back into, and make sure every piece sits firmly so nothing can shift when animals move around it.

Getting the water ready first

Check the water before the shrimp is ordered, not after it arrives. OATA's first test is simple: ammonia and nitrite should both read zero. It also stresses stocking slowly, because the bacteria in a maturing filter have to increase every time more livestock is added and feeding goes up.

Adding too much, or adding it too quickly, can cause what OATA calls new tank syndrome. There are not enough nitrifying bacteria to cope with the extra waste, ammonia and nitrite climb to unhealthy levels, and invertebrates can become ill or die. A Fire Shrimp should therefore join an aquarium that already holds zero ammonia and nitrite through normal feeding, and it should be the only new arrival for a while, so that you can confirm the readings stay steady.

Equipment checklist

• An aquarium as large as is practical for you, with a working filter: live rock with good flow, an internal or external filter, or a sump.
• A protein skimmer, which OATA describes as beneficial for removing dissolved organic waste.
• A heater with a thermostat and a thermometer you can read easily.
• Test kits for ammonia, nitrite, nitrate and pH, plus a hydrometer or refractometer for salinity.
• Live or artificial rock arranged with overhangs and gaps.
• A siphon and a clean container kept only for mixing replacement salt water.

Water values and testing

According to OATA, marine crustaceans are usually undemanding of water chemistry. The table below gives the suggested parameters from its care sheet for marine crustaceans. They are a general guide for this group of invertebrates rather than an optimum measured for Lysmata debelius itself, so use them as the working range for planning.

Using the ranges in a reef aquarium

If your Fire Shrimp will share a reef aquarium with corals or other more sensitive animals, OATA notes that some of these values will need to be altered to suit them. Where the needs of the reef and the crustacean guidance differ, plan around the figure that keeps every animal in the system comfortable, and move any value gradually rather than in one step.

What the numbers mean

• Salinity: expressed here as specific gravity, the density of the aquarium water compared with fresh water. A hydrometer or a refractometer gives the reading.
• pH: how acidic or alkaline the water is. Marine aquariums run alkaline, and the range above sits on the alkaline side of neutral.
• Carbonate hardness (dKH): the water's buffering capacity, which helps to hold pH steady between water changes.
• Calcium and magnesium: two of the major dissolved elements in salt water, measured in parts per million, roughly equivalent to milligrams per litre.
• Ammonia, nitrite and nitrate: the three stages of the nitrogen cycle described in the set-up section, from the most toxic to the least.

What to test

OATA recommends testing to monitor ammonia, nitrite and nitrate. Crustaceans can be stressed by even the smallest amounts of ammonia and nitrite, which may then lead them to develop various diseases, so those two readings are the ones to act on first. Nitrate is the end product of the cycle and builds up between water changes; keeping it no higher than 50 mg per litre is one of the main jobs of the weekly change.

Salinity needs its own attention. Water evaporates from an aquarium but the salt stays behind, so a tank that is never topped up slowly becomes saltier. Check the specific gravity regularly and replace evaporated water with fresh water rather than more salt water, so the reading stays inside 1.023–1.026.

If ammonia or nitrite ever read above zero, treat it as a warning about the whole system rather than the shrimp alone. Hold off on any new livestock, feed sparingly, check that the filter is running freely and keep testing until both readings are back at zero. A nitrate reading creeping towards 50 mg per litre is a sign to look again at how much food goes in and how consistently the weekly change is done.

Keep a simple log of every result. One reading tells you where the water stands on the day you test; a run of readings shows you which way it is moving, and that is usually the earliest warning you will get that something in the system has changed.

Moulting and growth

Crustaceans have a hard outer skeleton, the exoskeleton, and a body divided into segments. To grow, a Fire Shrimp has to shed that exoskeleton and form a new, larger one, and OATA notes that empty shells are a common sight in an aquarium for exactly this reason. Understanding the cycle saves a lot of unnecessary worry.

Finding an empty shell

A cast shell can look remarkably like a whole shrimp lying on the rock or the substrate, and it alarms many new keepers. Before assuming the worst, look for the living shrimp in its usual hiding places. A moult is a normal part of growing, and each one marks a step up in size from the M or L/XL shrimp that first went into the aquarium.

The soft-shell days

After moulting, OATA says it takes a couple of days for the new exoskeleton to harden, and the animal will often hide during this time. That is normal behaviour, and it is the main reason rock with hiding places is essential. Resist rearranging the rockwork or coaxing the shrimp out to check on it; give it the time it needs and keep the water steady.

When moulting goes wrong

OATA includes moulting problems among the changes to watch for: difficulty moulting, incomplete shedding of the exoskeleton, a soft-shell condition that lasts longer than it should, and changes in the normal moulting frequency. If you see any of these, start with the water. Test ammonia, nitrite and nitrate, and compare salinity, temperature and pH with the ranges in the water table before changing anything else.

Feeding

Marine crustaceans vary in their dietary requirements, but OATA notes that most species are omnivorous, eating algae, detritus and small meaty items. It recommends a varied diet, such as nori algae sheets, small frozen foods like brine shrimp, and pellets. Build a Fire Shrimp's menu on that variety rather than relying on a single food.

How much and how often

Because many crustaceans graze throughout the day, OATA says it is not possible to give a fixed number of feeds, and the right amount also depends on how much natural food the aquarium already provides. When you do offer extra food, take care not to overfeed. Uneaten food breaks down and releases toxic waste into the water, which works directly against the stable conditions a shrimp relies on.

In practice, offer small portions and watch where the food goes. If the fish take most of it before the shrimp reaches it, a small piece placed near the rock where the shrimp shelters gives it a fair share. If food is still lying untouched later on, remove it and offer less next time.

Signs the feeding is about right

Good feeding shows up in the aquarium as much as in the shrimp. Food should be taken rather than left to rot on the rock or substrate, ammonia and nitrite should stay at zero, and nitrate should stay within OATA's 50 mg per litre ceiling between water changes. If leftovers keep appearing or nitrate rises quickly, cut the amount back before you change anything else.

Clean-up jobs belong to other species

OATA describes some crustaceans, such as mithrax crabs and hermit crabs, as grazers that eat particular types of algae, and it names the peppermint shrimp, Lysmata wurdemanni, as an eater of unwanted Aiptasia anemones. Those examples are other species. Choose a Fire Shrimp for itself, and plan any algae or pest control around animals known for that job.

Arrival day and the first hours

Your shrimp is hand-packed by our team, bagged in pure oxygen and sent in an insulated poly box, with a heat pack when the weather calls for it. A licensed live-animal courier carries the parcel, and we email you the tracking number and your confirmed delivery date so that you know when to be in. Someone needs to be at the delivery address to receive it, because live animals cannot be left unattended.

The day before

Test ammonia and nitrite, and check temperature and salinity, the day before the shrimp is due, so that nothing needs correcting while it waits in its bag. Clear a space at the surface of the aquarium where the bag can sit without being pushed around, and have your phone charged and ready for the unboxing video.

Opening the parcel

The Live Arrival Guarantee depends on three things: someone receiving the parcel, the parcel being opened and inspected the same day it arrives, and a continuous unboxing video that starts with the parcel still sealed. The steps below keep you within those conditions and give the shrimp a gentle start.

1. Be at home on your confirmed delivery date to take the parcel in person.
2. Before anything is opened, start one continuous unboxing video. It should show the sealed parcel with the outer box visible, you opening it in one take, and the shrimp still inside its sealed bag.
3. Check the shrimp's condition in the bag while you are still filming, on the day it arrives.
4. Float the sealed bag in the aquarium for 20–30 minutes before releasing the shrimp.
5. Release the shrimp into the aquarium without pouring the bag water into your tank.

Why the unboxing video matters

The video policy is there to make claims quicker, clearer and fair for genuine customers. Our licensed live-animal courier may ask us for continuous unboxing evidence when we raise a claim, and a clip that runs without a break from the sealed parcel to the shrimp in its bag shows its condition before anything has been disturbed.

If anything has gone wrong, contact us the same day, with WhatsApp the fastest route, and send your order number with the unboxing video. We will arrange a replacement or refund. The full delivery and Live Arrival Guarantee policy sets out every condition.

After release

Once the shrimp is in, leave it to find its own way around the rockwork. Keep feeding light while it settles, and watch it against the signs listed under routine care. A new arrival also adds waste and feeding to the system, so test ammonia and nitrite over the following days to confirm that the filter is coping, just as OATA advises whenever livestock is added.

Routine care and health checks

Weekly maintenance

OATA strongly recommends a partial water change of 25% at least once every week. A siphon is useful for lifting solid waste out of the gravel as you go. Prepare the replacement salt water in advance so that its salinity and temperature already sit inside the ranges in the water table before it goes in.

Filters should be well maintained, with regular checks and cleaning to prevent blockages. If the filter needs cleaning, do not run it under the tap: any chlorine or chloramine present may kill the beneficial bacteria established in the media. Rinse it lightly in the tank water you have just removed during the water change instead, which keeps the loss of bacteria low. Protein skimmers need regular cleaning too, so that they keep performing.

A simple weekly routine

1. Test ammonia, nitrite and nitrate, and read salinity, temperature and pH.
2. Siphon solid waste from the gravel while you draw off roughly a quarter of the water.
3. Refill with salt water that already matches the aquarium's salinity and temperature.
4. Rinse any filter media that needs it in the water you removed, never under the tap.
5. Clean the protein skimmer if it needs attention.
6. Watch the shrimp for a moment against the signs listed below, and note anything new in your log.

Signs to watch for

Every animal shows small variations in behaviour and appearance, so learn what is normal for your shrimp. OATA suggests keeping an eye on changes in the following areas, because spotting them early helps you deal with a problem before it becomes a real health issue.

• Movement: reduced activity, long periods of inactivity, difficulty walking or swimming, loss of co-ordination, repeated attempts to leave the water or unusual movement patterns.
• Colour: turning a darker or paler colour than normal.
• Temperament: a change in aggression, or hiding more than usual beyond the normal hiding after a moult.
• Condition: damage to the exoskeleton, limbs, claws, antennae or eyes; lesions; discolouration; white or fluffy growths; or lost limbs or appendages.
• Moulting: difficulty moulting, incomplete shedding, a soft shell that lasts too long or a change in normal moulting frequency.
• Feeding: eating less, or losing interest in food.

When something changes, test the water before anything else. Ammonia or nitrite above zero, or salinity, temperature or pH outside the ranges in the water table, is the first thing to put right. A calm, consistent routine of testing, feeding sparingly and changing water every week is the best protection a shrimp has.

Choosing tank mates

OATA points out that marine crustaceans vary in their compatibility, so every combination deserves a check before you buy. The general rule it gives is clear: marine crustaceans will 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.

Fish

Reef-safe is the trade's shorthand for fish that are normally kept alongside corals and invertebrates. When you plan a Fire Shrimp's neighbours, start with that label and then look at each fish in its own right, because adult size, diet and habits all affect how it will treat a shrimp. A fish that is not reef-safe is likely to see a shrimp as food, so keep the two apart.

Crabs, lobsters and hermit crabs

Some scavengers, including lobsters and crabs, are opportunistic and may prey on slow-moving tank mates, so OATA advises mixing them carefully. A freshly moulted shrimp hides until its new shell hardens, and in a tank with opportunistic scavengers those hiding places matter even more. Hermit crabs should always have ample food and plenty of spare shells, so that they are not tempted to attack snails for theirs.

Cleaning behaviour

Lysmata debelius is a cleaner shrimp. OATA gives a relative, the cleaner shrimp Lysmata amboinensis, as an example of a crustacean that may eat parasites on larger fish. Enjoy any cleaning you see as natural behaviour, but don't buy a Fire Shrimp to treat a sick fish: a fish with a health problem still needs its own diagnosis and care.

Adding it to an existing community

Even with compatible tank mates, add new animals slowly. Each addition increases waste and feeding, and the filter bacteria need time to catch up. Introduce the Fire Shrimp on its own rather than alongside several other new arrivals, and let the aquarium settle before the next purchase.

Questions to ask about any tank mate

• Is the fish considered reef-safe, or is it a species that eats crustaceans?
• Is it an opportunistic scavenger, such as a crab or lobster, that may take slow-moving tank mates?
• Does the rockwork leave the shrimp enough places to hide after a moult?
• Is the aquarium ready for another addition, with ammonia and nitrite still at zero after the last one?

If you are planning a wider invertebrate line-up, the marine invertebrates collection shows the animals we offer. Treat each one as a separate compatibility decision: sharing a collection says nothing about whether two species can share a tank, and OATA's advice to check compatibility before introducing any crustacean applies every time.

Questions keepers ask

What size aquarium does a Fire Shrimp need?

OATA's marine crustacean guidance is to buy as large an aquarium as is reasonably possible, with at least 40 litres for smaller crabs and shrimps and more space for larger crustaceans, the right size varying by species. Treat 40 litres as a floor for small crustaceans in general rather than a target. Whatever the volume, the aquarium needs a working filter and live or artificial rock with places to hide.

Is a Fire Shrimp suitable for a beginner?

It suits a keeper who already runs a stable marine aquarium better than someone setting up a first tank. The water must hold zero ammonia and nitrite before the shrimp arrives, and it needs a steady routine of testing and a 25% water change every week, because crustaceans can be stressed by even the smallest amounts of ammonia and nitrite. If your aquarium is new, let it mature first and add the shrimp later.

What temperature, pH and salinity does a Fire Shrimp need?

OATA's broad guidance for marine crustaceans is 24–26°C, pH 7.9–8.3, salinity 1.023–1.026 and carbonate hardness 8–12 dKH, with ammonia and nitrite at zero and nitrate no higher than 50 mg per litre. In a reef aquarium, some values may need adjusting to suit more sensitive animals, so plan around the needs of everything in the system.

What does a Fire Shrimp eat?

Offer a varied diet, as OATA recommends for marine crustaceans: nori algae sheets, small frozen foods such as brine shrimp, and pellets. Many crustaceans graze through the day, so give small amounts and remove anything left uneaten, because decaying food releases toxic waste into the water.

Which fish can live with it?

Marine crustaceans generally mix with fish considered reef-safe. Fish that are not reef-safe are likely to prey on shrimps and should not be kept with them. Check each fish individually before adding it, and add new animals one at a time.

Can it live with crabs and other invertebrates?

Take care with crabs and lobsters: OATA describes these scavengers as opportunistic and says they may prey on slow-moving tank mates, so mix them carefully. A freshly moulted shrimp hides until its new shell hardens, so plenty of rockwork matters in a mixed invertebrate tank. Hermit crabs should always have ample food and spare shells.

How does a Fire Shrimp arrive alive in the UK?

It is hand-packed in a bag of pure oxygen inside an insulated box, with a heat pack when the weather calls for it, and carried by a licensed live-animal courier. Someone must be in to receive the parcel and open it the same day. Before opening, start one continuous unboxing video that runs from the sealed parcel to the shrimp in its bag, then float the bag for 20–30 minutes and release the shrimp without the bag water. For a Live Arrival Guarantee claim, get in touch the same day with your order number and that video.

Sources

• World Register of Marine Species: Lysmata debelius Bruce, 1983, the accepted scientific name and its family, Lysmatidae.
• Wikipedia: Lysmata debelius, a species summary covering its Indo-Pacific range and its trade names.
• Ornamental Aquatic Trade Association: how to look after marine crustaceans, the care sheet for marine crustaceans as a group behind the water values, set-up, feeding, maintenance, health signs and compatibility advice on this page.
• RSPCA: fish environment, on how biological filtration deals with ammonia, nitrite and nitrate.
• Tropical Fish Co delivery and Live Arrival Guarantee policy, for packing, courier, arrival steps and claim conditions, linked in the arrival section above.