Harlequin Shrimp
Hymenocera picta
A breathtaking shrimp that eats ONLY starfish - a specialist that needs a steady supply of sea stars.
| Difficulty | Advanced |
| Min. Tank Size | 75 L |
| Temperature | 24.0–27.0 °C |
| pH Range | 8.1–8.4 |
| Max Size | 5.0 cm |
| Lifespan | 2-3 years |
| Diet | Carnivore |
| Temperament | Peaceful |
Overview
The Harlequin Shrimp (Hymenocera picta) is a breathtaking shrimp that eats ONLY starfish - a specialist that needs a steady supply of sea stars.
This guide explains what the Harlequin 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 specialist feeder with very particular needs - rewarding to keep, but only for those who can meet its diet.
Care Level
It has specialist needs and is best left to experienced reefers who can meet them.
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
This animal has a strict specialist diet (see the overview) - only keep it if you can reliably provide that food.
Is It Reef-Safe? Compatibility
It has special considerations - read the overview carefully, as it is not a standard reef-safe clean-up animal. 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 Harlequin Shrimp Right for Your Reef?
The Harlequin Shrimp is a worthwhile addition for keepers who can meet its needs. 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.
