Pistol Shrimp
Alpheus randalli
A burrowing shrimp that pairs with a watchman goby, snapping its claw with an audible pop.
| Difficulty | Beginner |
| Min. Tank Size | 40 L |
| Temperature | 24.0–27.0 °C |
| pH Range | 8.1–8.4 |
| Max Size | 5.0 cm |
| Lifespan | 3-5 years |
| Diet | Carnivore |
| Temperament | Peaceful |
Overview
The Pistol Shrimp (Alpheus randalli) is a burrowing shrimp that pairs with a watchman goby, snapping its claw with an audible pop.
This guide explains what the Pistol Shrimp does for your reef, how to care for it, whether it is reef-safe, and what to watch out for.
What It Does for Your Tank
It is a scavenger that mops up leftover food and detritus, an active and characterful member of the clean-up crew.
Care Level
It is hardy and easy, ideal for beginners, as long as it is acclimated slowly and the tank is mature.
Water Parameters & Acclimation
Keep a stable reef system at 24-27 °C, pH 8.1-8.4 and salinity 1.024-1.026 (35 ppt). Hold alkalinity at 8-12 dKH, calcium at 400-450 ppm and magnesium at 1300-1400 ppm, with ammonia and nitrite at zero. Stability matters more than chasing perfect numbers, so test regularly and avoid sudden swings.
Like all marine invertebrates it is very sensitive to copper and to sudden changes, so never use copper-based medications in the tank and always drip-acclimate new arrivals slowly over an hour or more.
Feeding
Feed meaty foods (mysis, pellets, chopped seafood) a few times a week in addition to what it scavenges.
Is It Reef-Safe? Compatibility
It is reef-safe and peaceful with corals and fish - a trusted clean-up crew member. Provide one hiding spot per animal and avoid overstocking your clean-up crew, or some will starve.
Common Problems & Care Tips
The biggest risks are copper exposure, ammonia spikes and rushed acclimation - go slow and keep water stable. Snails that fall over should be turned upright; provide spare shells for hermit crabs to prevent squabbles; and never buy a clean-up crew bigger than your tank can feed.
Is the Pistol Shrimp Right for Your Reef?
The Pistol Shrimp is an easy, useful addition for almost any marine tank. Build a balanced clean-up crew rather than relying on any single species, and pair it with our marine fish and coral guides.
How to Tell Males from Females
Females are noticeably larger and deeper-bodied, with a curved underside to the tail that creates a visible 'saddle' of developing eggs behind the head. Males are slimmer and more transparent. The difference becomes obvious from around four months old.
