Common name: harlequin shrimp

General information

The Harlequin Shrimp, scientifically known as Hymenocera picta, is a captivating and colorful marine invertebrate that is highly sought after by reef aquarium enthusiasts. This species is renowned for its striking appearance, featuring a white body with large, bright blue to purple spots. The males are typically smaller than the females, and both possess flat, paddle-like claws that are used for manipulating their prey.

Care

Harlequin Shrimp require a specialized diet, primarily consisting of starfish, including the Asterina species which are small and relatively easy to keep in an aquarium. They are sensitive to water quality and require a well-established reef tank with stable parameters. These shrimp do not tolerate high nitrate levels or fluctuations in water chemistry. Providing plenty of live rock for hiding and foraging is essential for their well-being.

Reproduction

Breeding Harlequin Shrimp in captivity can be challenging. They are known to form monogamous pairs, and the female carries the eggs under her abdomen until they hatch. The larvae go through several planktonic stages before settling down and morphing into their adult form. Successful breeding requires a separate rearing tank with optimal water conditions and a steady supply of starfish for the larvae to feed on.

Symbiosis

While not involved in symbiosis in the traditional sense, Harlequin Shrimp have a unique ecological role as predators of starfish. This can be beneficial in controlling populations of pest starfish in the aquarium. However, their diet specificity means they are not suitable for all reef tanks, especially those without a sustainable source of starfish.

Habitat

Hymenocera picta is found in the tropical waters of the Indo-Pacific region, from the Red Sea to the central Pacific. They typically inhabit coral reefs and prefer to dwell in crevices and under ledges during the day, emerging at night to hunt for starfish.