Harlequin Shrimp (Hymenocera Picta)

Species Name : Hymenocera Picta

Care Level : Moderate

Temperament : Peaceful

Color : Blue, Pink, Tan, White

Diet : Carnivore

Reef Compatible : Yes

Water Conditions : 72-78° F, dKH 8-12, pH 8.1-8.4, sg 1.023-1.025

Max. Size : 2 inches

Origin : Africa, Indian Ocean

Family : Gnathophyllidae

Supplements : Calcium, Magnesium, Iodine, Trace Elements

Harlequin Shrimp (Hymenocera Picta) commonly known as the Clown Shrimp, is a species of saltwater shrimp found at coral reefs in the tropical Indian and Pacific Oceans.

The Harlequin Shrimp might be one of the easiest shrimp to identify as its patterning is unmistakable. These shrimp are cream-colored with pastel blue, pink, and purple spots. They have two large flattened claws and an ornate head that is believed to help better detect scents through the water. Unlike other shrimp, which tend to have very long and thin antennae, theirs are flat and leaf-shaped. These shrimp can grow to be 1.5-2.0 inches (3.8-5.1 cm) when fully grown; males tend to grow slightly smaller than females, but other differences between males and females are limited.

In nature, this species is almost always found in pairs, so it is recommended to do the same in an aquarium. If you’d like to keep a pair of harlequin shrimp in your own aquarium, keep in mind that these guys are pretty sensitive. High water quality is very important, which means they might not be the best choice for beginning aquarists. Because Harlequin Shrimp don’t grow all that large, an aquarium of 10 gallons or up should work fine for them, although keep in mind that large aquariums are easier to keep stable.

As for tankmates, like other shrimp species, harlequins are aggressive towards other shrimp. 

These shrimp can do well in reef systems provided you are willing to meet their unique dietary needs—they will only eat live sea stars. They are very skilled at flipping over a slow starfish on its back, and eating the tube feet and soft tissues until it reaches the central disk. They, usually one female and one male, use their claws to pierce the tough skin and feeding legs to help them maneuver the starfish. Sometimes, the starfish will shed the arm that the shrimp attacked and regrow it, but it is usually too wounded to regrow. They may also feed on sea urchins, because they have tube feet, as well, but that is rare and only if starfish are not available. They will also eat small chocolate chip stars Protoreaster nodosus, those in the genus Fromia, and some of the sand-sifting stars. Luckily, they will also consume the Asterina stars that often proliferate among live rock and are therefore quite useful in controlling the population of such creatures—if one can live with their gruesome feeding behavior.