Harlequin shrimp, also known as hymenocera picta, are a type of rare shrimp located in the Indian and Pacific oceans. These shrimp live on coral reefs in crevices or under rocks and often stay in the same area for months or even years. They are usually found in pairs, as they are monogamous creatures that mate for life. Harlequin shrimp measure between 1 and 2 inches (2 and 5 cm) in length, with the average shrimp being approximately 1-inch-long (2 cm). In general, males are smaller in size than females.
Some animals camouflage with their environment for survival. Harlequin shrimp are bright in color, with their bodies pinkish-white and dotted with pink, purple or red spots. In regards to survival, it might seem odd that harlequin shrimp are so noticeable in their coloring. While some animals blend in to stay alive, though, others stand out to keep predators at bay; this is because in the wild, when an animal is bright in color, it often indicates that it is toxic. Since there have been no findings of toxins in harlequin shrimp, it is thought that the bright coloration only gives the impression of toxicity.
Harlequin shrimp are noted for their eating habits. They feed at night and mostly prey on starfish, locating them through scent. Since these shrimp more often than not live in pairs, they work together to attack their prey. They pry a starfish’s arms from the rock and then overturn it to feed on its tube feet.
The shrimp slowly feed while the starfish is still alive. They keep the prey immobilized and, in some instances, they even feed it to keep it alive so that they can continue eating it later. It can take days for the shrimp to feed on one starfish. It is possible for the prey to escape, but it would have to detach from its own arm to do so.
When owning harlequin shrimp, it is probably best to have them in pairs. Though many people keep, or want to keep, harlequin shrimp in their aquariums, it can be hard to maintain them in captivity because of their diet. An owner would have to provide live starfish for food, which can become expensive over time. Sometimes, it will also take a while to find the right kind of starfish that the particular shrimp will eat. If the shrimp is not properly taken care of, it will not survive as long as it normally could.