Livestock · Shrimp

Tiger Pistol Shrimp

Alpheus bellulus

The engineer of the goby-shrimp partnership — it builds the burrow, the goby keeps watch.

Difficulty: Beginner–IntermediateOrnamental shrimpReef-safe

The tiger pistol shrimp (Alpheus bellulus) is one half of the reef's most charming partnership. Nearly blind, it digs and constantly maintains a burrow in the sand; in return, a watchman goby stands guard at the entrance and warns it of danger with a flick of its tail. The famous "snap" — loud enough to startle you — is the shrimp's spring-loaded claw, used mostly for defence.

Good to know: The loud "snap" is normal; famously pairs with a watchman goby.
📊 What keepers actually ask: Sought specifically for the goby-shrimp pairing; the recurring surprises are the loud snapping (normal) and how rarely it's seen (it's a burrow-dweller).

Care at a glance

Adult sizeAround 2 in.
Minimum tank20+ gallons with a sand bed deep enough to burrow, plus rubble to build with.
Temperature75–82°F (24–28°C).
pH8.1–8.4.
Specific gravity1.023–1.026 (reef-standard ≈35 ppt).
Other targetsStandard reef calcium and alkalinity support healthy moulting; like all inverts it has zero tolerance for copper.
DietScavenger — detritus, leftover food and meaty scraps gathered near its burrow.
TemperamentPeaceful and reef-safe; reclusive. Famous for pairing with a shrimp goby (such as the yellow watchman).
Reef-safeYes — it stays in and around its burrow; the snapping is defensive, not predatory.
Natural rangeIndo-Pacific.
Beginner-friendly, done right. Undemanding and fascinating, best known for its symbiosis with a shrimp goby. Give it a sand bed deep enough to burrow (with some rubble or shell to shore up tunnels), and ideally pair it with a watchman goby — the two share a burrow, the shrimp digging and the goby watching. The loud "snap" is normal and harmless to you and your reef. It may occasionally hunt if underfed, so keep the tank fed. Standard invert care: drip-acclimate, no copper.

The fish store gets these wrong

Common myths, kindly corrected — no shame for having believed them.

  • "A pistol shrimp will crack my glass or kill my fish." No — the snap is a defensive stun and is no danger to your tank glass or your fish; it's a reclusive scavenger.
  • "It needs the goby to survive." The partnership is optional for the shrimp — but pairing it with a watchman goby is the whole appeal, and both do better for it.

Before you buy

  • A sand bed deep enough to burrow, plus rubble or shell for tunnel-building.
  • Ideally a shrimp goby (yellow watchman) to pair it with.
  • A cycled tank; drip-acclimate; never any copper. Expect to rarely see it at first.

Signs something's wrong

A struggling invert is usually telling you about water quality, acclimation, or (for shrimp and crabs) a fresh moult — here's what to watch for:

  • Never leaving the burrow or not eating — make sure food reaches near the entrance; check parameters.
  • On its side and not a moult — check salinity and for copper.

Never

  • Never keep it bare-bottom — it needs sand to burrow.
  • Never dose copper with shrimp in the tank.
  • Never drop it straight in — drip-acclimate.

Common tiger pistol shrimp questions

Do pistol shrimp and gobies really pair up?

Yes — it's a genuine symbiosis. The near-blind pistol shrimp digs and maintains a burrow, and a shrimp goby (like the yellow watchman) shares it and stands guard, warning the shrimp of danger with its tail. Buy them together, or add the shrimp first.

Is a pistol shrimp's snap dangerous?

Not to you or your tank — the snap is a spring-loaded claw used mainly for defence. It's loud (you'll hear clicks), but it won't crack aquarium glass or harm your fish; the shrimp is a reclusive scavenger.

Is the tiger pistol shrimp reef-safe?

Yes — it stays in and around its sand burrow eating detritus and scraps, and leaves corals alone. Keep it fed so it has no reason to hunt.

Does a pistol shrimp need a sand bed?

Yes — it's a burrower, so it needs a sand bed deep enough to dig in, ideally with some rubble or shell pieces to shore up its tunnels.

Will I ever see my pistol shrimp?

Sometimes — it's a burrow-dweller, so you'll mostly see it at the entrance shifting sand, especially if it's paired with a goby standing guard. Hearing the occasional snap is normal even when it's hidden.


Sources & further reading

This guide was written and fact-checked against these authorities. It's honest, general guidance — not a diagnosis, and not a substitute for an aquatic vet or your own test kit:

Written and fact-checked by The Coralkin Team against marine-aquarist sources — if your tiger pistol shrimp is struggling, it's almost always water quality, acclimation or a moult — check those first and ask an experienced reefer. We never guess a care number.

🔬 Review status: team-written and fact-checked against cited sources · not yet reviewed by a marine vet. How we research & fact-check →

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