Most divers in Hawai‘i will never see this rare shrimp, but even if they did they more than likely would not know what they are looking at! This two-inch-long shrimp looks more like an exotic orchid than it does an animal. These unusual looking shrimp are cream colored with red dots, and their front pincers are modified into large, leaf-like plates. When you find this shrimp they are usually in pairs, and are very close to a sea star. Out of over 3,000 dives I have done in Hawai‘i I have only seen the harlequin shrimp three times!
Most divers in Hawai‘i will never see this rare shrimp, but even if they did they more than likely would not know what they are looking at! This two-inch-long shrimp looks more like an exotic orchid than it does an animal. These unusual looking shrimp are cream colored with red dots, and their front pincers are modified into large, leaf-like plates. When you find this shrimp they are usually in pairs, and are very close to a sea star. Out of over 3,000 dives I have done in Hawai‘i I have only seen the harlequin shrimp three times!
Harlequin shrimp females are larger than the males, and they are quite territorial. Their main food are sea stars, which they turn over and eat from the bottom. The sea star will often let go of a leg when attacked by the shrimp and escape. The sea star will grow back a new leg, and it may take the shrimp an entire week to eat the severed leg. For the harlequin shrimp, the sea star is a renewable food source, which is good because here in Hawai‘i we have very few sea stars for them to feed on. One pair of shrimp can live off of a single sea star by eating one of its legs that will grow back for the shrimp to eat again! Many sea stars are toxic, and the shrimp may become toxic after eating the star and helps protect them from predators.
The harlequin shrimp have a very unusual way of protecting themselves, as they use their flat blade like pincers as weapons. It is really neat to watch because the shrimp rotates the pincers in front of its body and looks like it is practicing karate. This behavior is so strange looking, but confuses fish that like to eat shrimp. Most shrimp live back in caves and cracks in the reef, and they don’t often come out in the open, but the harlequin shrimp are so bold they just sit right up on top of the reef and go through their karate routine every time a diver or potential predator goes by. They look like they should be in a cartoon on TV and not out on the open reef.
You can see the harlequin shrimp in action on my Youtube channel at Underwater2web. The shrimp are also in my documentary movie about marine life at Sharks Cove in O‘ahu.
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Terry Lilley is a marine biologist living in Hanalei and co-founder of Reef Guardians Hawai‘i, a nonprofit on a mission to provide education and resources to protect the coral reef. To donate to Reef Guardians Hawai‘i go to www.reefguardianshawaii.org.
