Harlequin shrimp care

Quick reference

What is a harlequin shrimp?

Hymenocera picta feeds exclusively on starfish.^[2] A study of captive feeding found it starts on a blue Linckia by removing the tube feet and gonad tissue, in episodes lasting 30–60 minutes.^[2] TFH says pairs flip a star over and eat it from the arm tips toward the centre, and that a 4–6 inch star feeds them for about four weeks.^[1]

Feeding

TFH says harlequins eat only live sea stars, and won't touch dead or defrosted frozen ones. It names blue Linckia, small chocolate chip stars (Protoreaster nodosus) and Fromia, and notes they'll eat Asterina too.^[1] Owners on Meerwasser-Lexikon report pieces of frozen starfish arm accepted by some pairs, and a hungry pair eating up to 15 small Asterina a day; they also warn that a large star's uneaten remains rot if left in.^[3] Budget for it: one owner there put the cost at about €500 a year.^[3]

Aggression and spacing

TFH says they often form mated pairs and become territorial, so keep one or one pair per tank.^[1] Meerwasser-Lexikon adds that they're sensitive to other shrimp.^[3]

Tankmates

Reef safe for corals, but every starfish is food, including ones you want.^[1] Meerwasser-Lexikon says Fromia nodosa and serpent stars aren't eaten, small short-spined urchins can have their tube feet nibbled, and large wrasses and snappers eat harlequins.^[3] TFH warns against freshwater dips, which can kill them.^[1]

Disease and quarantine

Acclimate slowly, matching temperature and salinity.^[1] TFH says they're defenceless while moulting and need secure hiding places, and to keep calcium and magnesium from dropping.^[1] Meerwasser-Lexikon says they don't tolerate high nitrate and need a good food supply to moult regularly.^[3]

Breeding

Captive breeding is possible but too limited to meet demand.^[3] Pairs spawn in home tanks; rearing the larvae is the hard part.^[3]

Troubleshooting

Common mistakes

• •Buying them to clear Asterina, then having nothing to feed them when the Asterina are gone.^{[1, 3]}
• •Offering frozen food alone.^[1]
• •Keeping them with starfish you want to keep.^[1]
• •Adding them with large wrasses.^[3]

Equipment & food for this species

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Inverts need stable salinity — use a refractometer, not a hydrometer.

Harlequin shrimp FAQ

What do harlequin shrimp eat?

Only starfish. TFH says live stars only, such as blue Linckia, small chocolate chips, Fromia and Asterina.^{[1, 2]}

Will harlequin shrimp eat Asterina?

Yes: a hungry pair can eat up to 15 small Asterina a day, according to Meerwasser-Lexikon owners.^[3] Plan what to feed them once the Asterina are gone.^[1]

How often do harlequin shrimp need to eat?

TFH says a 4–6 inch star lasts about four weeks.^[1]

Are harlequin shrimp reef safe?

Yes for corals, but they eat starfish and may nibble the tube feet of small urchins.^{[1, 3]}

Can you keep two harlequin shrimp?

A mated pair, yes; TFH says pairs become territorial, so one pair per tank.^[1]

How long do harlequin shrimp live?

Meerwasser-Lexikon gives about 2–3 years; we found no study.^[3]