Harlequin shrimp

Appearance

The Hymenocera, or Harlequin shrimp, is usually cream colored or white with occasional spots. Around the Pacific Ocean, many of these shrimp will have red spots while the Indian Ocean shrimp typically have purple spots while its close cousin, the Hawaiian H. picta, has purple and red spots off of their body, the shrimp have two walking legs on each side and large claws, or cheliped. The claws and eyes appear to look flattened and thin. On its head the shrimp have "petal-like sensory antennules" to smell out their prey. Their body usually reaches up to 5 cm or 2 inches, and the male is just a little bit smaller than the female.[University of Hawaii Mãnoa Education Department. "Marine Life Profile: Harlequin Shrimp." Waikiki Aquarium, n.d. Web

Naming

It is usually considered the only species in the genus "Hymenocera", but some split it into two species: "H. picta" from the central and east Pacific where the spots are deep pinkish-purple with a yellow edge, and "H. elegans" from the Indian Ocean and west Pacific where the spots are more brownish and have a blue edge.

Habitat

These shrimp are typically found in Hawaii through the Indo-Pacific below the intertidal zone on coral reefs. They prefer temperatures of 72-82 degrees Fahrenheit, but are very rare because of the changing coral reefs. Many people are now using these shrimp as pets because of their colorful bodies, so future pet owners need to be aware that these shrimp are very sensitive and any changes in temperature, water chemistry and salinity can be detrimental. Even high nitrate or copper levels can negatively harm the shrimp. They also are typically found with a mate in their natural habitat, but owners can keep them together as long as they can."Harlequin Shrimp - Hymenocera Picta - Small." Thatpetplace.com. N.p., n.d. Web. 30 Sept. 2013..

Food

Harlequin shrimp's only source of nutrition comes from starfish. They are very skilled at flipping over the 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, but it is usually too wounded to regrow. They may also feed on sea urchins but that is rare and only if they're very hungry because they have tube feet as well."Harlequin Shrimp - Hymenocera Picta." FreshMarine.com. N.p., n.d. Web. 30 Sept. 2013...