From ReefPedia

[edit] Harlequin Shrimp Scientific Name (Hymenocera Picta OR Elegans) Max. Size: (2") Tank Size: (Anything from a 2.5 onward.) Aggression: (Nonaggressive. Have been seen to attack snails, etc. but with no damage. DO NOT KEEP SEA STARS WITH THESE SHRIMP. THE SEASTAR WILL BE FATALLY INJURED.) Hardiness: (Relativley hardy, although it is a poor shipper. Sensitive to salinity changed.) Reef-Safe: (Yes, with the exception of sea stars.) Available as captive-bred: (Have been raised in captivity, but never commercially sold.) Hitchhiker? (No.)

Harlequin shrimp (Hymenocera picta)

Physical Description

Male harelquin flipping over a chocolate chip starfish.

With its large Paddle-Like front claws, this little shrimp quickly captures its prey by flipping it over. Both male and female have blue or purple spots all over their bodies and sharp, javelin like legs. The distinquishing characteristics between the male and female are size and color of pleopods. When grown the females are almost twice the size of the male and the male lacks the blue/purple spots under the tail that the females will have.

Distribution

(Throughout the Pacific Ocean.)

Taxonomic Stuff you know you Care About

(Kingdom: Animalia

Phylum: Arthropoda
Class: Malacostraca
Order: Decapoda
Family: Gnathophyllidae
Genus: Hymenocera
Species: Picta or Elegans)

• Genus: (Hymenocera)

• Species: (Picta or Elegans)

Behavior

(Very Peaceful, will usually only be seen while eating starfish. Most commonly underneath or behind rocks. Also on overhangs.)

Feeding

These beautiful shrimp will only feed on Starfish (phylum Echinodermata, class Asteroidea). They do consume the entire starfish if allowed enough time to do so. A pair of adult harelequins can consume a med/large chocolate chip starfish within 2 weeks leaving behind a pile of white pelleted remains. If you are thinking about getting a pair, be sure you are aware of the costs of keeping them well fed!

Breeding

Here you can easily see the plain white tail flaps on this male harlequin.

Mated pairs breed with every molt. The female holds the eggs under her tail until they have hatched and are ready to release. She will release the babies within 1 hour after the MH turn off. The young are difficult to raise to adulthood.

The distinquishing characteristics between the male and female are size and color of pleopods. When grown the females are almost twice the size of the male and the male lacks the blue/purple spots under the tail that the females will have.

Social Structure

Male and female harlequins have a strong bond and rarely are seperate from one another; hunting, sleeping and eating together. On the other hand, two males or two females will fight or avoid each other.

Additional Notes

Should only be attempted by experienced reefkeepers. These shrimp are sensitive to rapid salinity swings and poor water conditions. Keeping nitrates less than 10ppm, keeping them fed well, and perfoming regular water changes will ensure these adorable shrimp live a long happy life.