The peppermint shrimp is a small, translucent Caribbean shrimp striped in candy-cane red, bought almost exclusively for one job: eating Aiptasia, the stinging pest anemones that plague reef tanks.
Unlike its showy cousin the skunk cleaner shrimp, it is not a dedicated fish-cleaner and spends its days wedged deep in the rockwork, emerging mostly after lights-out.
It is cheap, peaceful, and genuinely effective pest control when you get the real thing.
That is the catch — 'peppermint shrimp' covers a complex of near-identical Lysmata species, and shops routinely mislabel the coral-nipping camel shrimp (Rhynchocinetes) as a peppermint, so buy from a source that can tell them apart.
The giveaway is the body and beak: a true peppermint has a slim, straight body with fine red stripes, while the camel shrimp is visibly humpbacked with a sharply upturned, hinged rostrum.
Housing
A mature, stable reef of 40 litres (10 gallons) or more is enough for one shrimp, with plenty of rockwork caves and overhangs because this is a cryptic, nocturnal animal that needs daytime cover.
Small groups of two or three work well in larger tanks and hunt Aiptasia more thoroughly than a lone shrimp.
Keep salinity locked at 1.025-1.026 (about 35 ppt) and temperature at 24-26C (75-79F), with no copper anywhere in the system.
Like all Lysmata shrimp it tolerates far less parameter swing than fish do, so sloppy top-offs and rushed water changes are the real hazards.
Do not add it to a brand-new tank; wait until the system has been cycled and stable for a couple of months so there is biofilm and detritus to graze between meals.
Diet
Aiptasia is the headline, and a hungry peppermint shrimp will mow down small and medium anemones, often overnight.
Be honest about the limits: individuals vary, large established anemones are frequently ignored, and a shrimp kept well fed on easier food may never touch an Aiptasia at all.
Beyond pest control it is a scavenger, picking over rockwork for detritus and leftovers after dark.
Target-feed a few sinking pellets or frozen mysis a couple of times a week so it does not go hungry, but keep portions lean while an Aiptasia outbreak is being cleared.
A genuinely underfed peppermint will start picking at easier targets, including LPS coral polyps and zoanthids, so the balance is lean feeding, not starvation.
Health
Acclimation is the make-or-break moment, as with all ornamental shrimp: drip-acclimate over at least an hour, because osmotic shock from a quick transfer is the classic first-day killer.
Copper-based medications are lethal to it at trace levels, so never treat the display and never reuse copper-dosed equipment.
Regular moulting is normal — you will find a perfect ghost shell on the sand and the shrimp will hide for a day or two while its new shell hardens.
Failed or incomplete moults usually point to unstable salinity, low calcium or magnesium, or iodine-poor water, so steady reef-standard alkalinity and mineral levels are the fix.
Expect a working lifespan of two to three years even in a well-run tank, and factor that into how attached you get.
Temperament
Peaceful toward fish, corals, snails, and other shrimp, the peppermint is a background animal rather than a pet you interact with.
Keepers used to a bold skunk cleaner riding their hand should expect the opposite: glimpses of antennae from a cave by day and cautious foraging at night.
It is reef-safe with an asterisk — a hungry individual may pinch food from coral mouths and occasionally pick at LPS or zoanthid polyps.
Groups get along fine, and since they are protandric hermaphrodites any pair will produce larvae, which become live food for the fish.
Check the stocking list both ways before buying: hawkfish, dottybacks, large wrasses, triggers, and puffers all treat a 5cm shrimp as an expensive snack.
A good fit for
Reef keepers fighting an Aiptasia anemone outbreak
Established, copper-free systems with stable salinity
Budget-friendly additions to a clean-up crew
Keepers happy with a shy, mostly nocturnal animal
Small reefs from 40L / 10gal upward
Common mistakes to avoid
Camel shrimp (humpbacked, hinged beak) sold mislabeled as peppermints — they nip coral
In a reef, stability matters more than any single target number. A parameter moving fast does more damage than a parameter sitting slightly off.
Go now
Any detectable ammonia or nitriteWater change now with matched, mixed and aerated saltwater. Stop feeding. Directly toxic, and a marine system has less margin than a freshwater one.
Now
Temperature or salinity has moved sharplyCorrect slowly, over hours, not minutes. Check the heater and the top-off. The speed of the change does the damage. Correcting fast repeats the injury in the other direction.
Now
Rapid gilling, or a fish hanging in the flow breathing hardIncrease aeration and check temperature and salinity. Warm water holds less oxygen, and a heater failure shows up here first.
Now
Today
White spots, or a fine dusting like icing sugarIdentify which parasite before treating. Most reef tanks cannot be treated in place. The two common parasites look similar and need different handling; velvet can kill a tank in days.
Today
Corals closed for more than a day, or receding tissueTest alkalinity first, and compare it against the last reading rather than a target. Unstable alkalinity is the most commonly cited coral killer, and a swing shows up in the trend, never in a single point.
Today
A new fish added without quarantine now looks unwellRemove it to a separate system today if you can. Nearly every wipeout in a reef tank traces back to a skipped quarantine.
Today
Quarantine every new animal, including corals and inverts. It is the single practice that separates a reef that lasts from a reef that restarts.
This is general guidance for a healthy adult, not a diagnosis. An exotics vet who knows your animal always overrides it — and the time to find one is before you need one.
What it really costs
Setup, monthly, first year and across a whole life, itemised and with the electricity worked out from the actual wattage. Published figures for the same animal disagree by a factor of four, so the calculator shows ranges rather than picking one.
Intermediate
Intermediate
Intermediate
Intermediate
Intermediate
Intermediate