Only two Hymenocera species are known to exist, Hymenocera picta and Hymenocera elegans. Both species are among the most beautiful and exotic looking ornamental shrimps in our oceans. Hymenocera picta is more reddish and occurs in the Central Pacific while Hymenocera elegans has a brown color and inhabits the Red Sea and Indian Ocean. Despite their unusual form and color pattern neither species is frequently seen in the aquarium trade. One reason is that they are quite rare nowadays and, since they feed at night, difficult to find. The other reason is that they exclusively feed on the viscera of echinoderms, particularly starfish. In the wild, both species form long term pair bonds and, unlike most invertebrates, are able to recognize their partners as individuals. Females are noticeably larger than males and carry the eggs.

Eastern Harlequin Shrimp - Hymenocera picta
First raised at RCT in October 1997

This species is well known in the Hawaiian Islands and used to be quite common. It will eat any of the starfishes that occur here locally but much prefers Linkia species. In captivity we found a pair requires about one starfish every 4-6 weeks.

Counterclockwise from top left: A pair of harlequin shrimps (female on right) A 9-day-old harlequin shrimp larva A 42-day-old harlequin shrimp juvenile 45-day-old harlequin shrimp juveniles feeding on a Linkia starfish

Eastern harlequin shrimps molt about every three weeks. A female produces anywhere from 100 to 3,000 eggs the day after molting. She carries this clutch for about 20 days if fertilization occurs. The eggs hatch over 1 to 2 nights, within 1 hour after the lights turn off. The larvae are able to feed on newly hatched brine shrimp the next morning. Over the next 30 to 50 days they undergo eleven molts before settling as lightly pink colored juveniles. Though the larvae can be raised exclusively on brine shrimp they undergo high mortality at certain stages unless specific conditions are provided. We therefore consider this species moderately difficult to raise.

Here at RCT we are against promoting the use of live starfish as food and will not be producing harlequin shrimp until the proper, alternate diet is developed.

Interesting Fact
Syd Kraul first cultured H. picta back in 1986 at the Waikiki aquarium.