Carnivorous marine crustaceans, recognized by their bold colors: Harlequin Shrimp.

Harlequin Shrimp are a captivating species found in the tropical Indo-Pacific and Hawaiian Islands, known for their unique hunting techniques and striking appearances.

A Spectacular Sight to Behold

These shrimp come in various colour variations, with Indo-Pacific harlequin shrimp sporting spots that tend to be browner with a blue outline, and their Hawaiian counterparts boasting large reddish purple spots often surrounded by yellow [1].

The Art of Hunting

Harlequin Shrimp are highly specialized predators, successfully subduing and eating sea stars despite their small size. Their hunting strategy involves a coordinated approach:

Detection and Approach

Using their sensitive antennae, Harlequin Shrimp detect the presence of starfish. Once a target is identified, they close in on the prey [1].

A Team Effort

If there is a mated pair, they will attack the starfish in unison, making their hunt more effective. This coordinated approach allows them to overpower a larger starfish [1].

Immobilization

The shrimp will use their claws to dig underneath the starfish and flip it over. Once upside down, the starfish is essentially immobilized because its suction-cup-like feet can no longer hold onto the substrate [1].

A Delicate Feast

After flipping the starfish, the Harlequin Shrimp methodically devour the starfish from its tips to its center, ensuring the starfish remains alive for as long as possible to maximize nutritional intake [1][2]. This prolonged feeding process can last up to two weeks [3].

To avoid scavengers or other predators, the shrimp often drag the starfish away to a private location, such as a cave or hiding spot, where they can feed without interruptions [1].

Capturing the Perfect Shot

Photographing these elusive creatures can be a challenge, as sightings are not guaranteed. However, once spotted, they may stay in one location for several months.

Fisheye lenses can provide a creative image with expansive backgrounds, but require getting very close to the shrimp to avoid making it appear non-existent in the frame [4]. Wet lenses provide additional macro capability for compact cameras, while a 60mm lens on a cropped sensor camera is good for photographing Harlequin Shrimp in their habitats [5]. A 100mm/105mm lens is great for filling the frame and blurring out the background, and for reaching hard-to-reach crevices where shrimp reside [5].

Respecting Marine Life

It is important to respect underwater marine life and not harass Harlequin Shrimp while photographing them. Aquarium collection for trade is a concern for Harlequin Shrimp, and careful management of strobes is necessary due to their reflective white bodies [6].

The Andaman Sea, Thailand, is a location where Harlequin Shrimp have been photographed with a pair keeping a tight grip on a sea star arm [7]. In the Mergui Archipelago, Burma/Myanmar, Harlequin Shrimp have been observed subduing Crown-Of-thorns sea stars and keeping them as live captives for 2 weeks or more [8].

[1] Harlequin Shrimp work in pairs to capture and consume sea stars

[2] Harlequin Shrimp feed exclusively on sea stars

[3] A sea star meal may last up to two weeks for Harlequin Shrimp

[4] Fisheye lenses can provide a creative image with expansive backgrounds

[5] Compact cameras can mimic the effects of a 60mm and 100mm lens

[6] Careful management of strobes is necessary when photographing Harlequin Shrimp

[7] The Andaman Sea, Thailand, is a location where Harlequin Shrimp have been photographed

[8] The Mergui Archipelago, Burma/Myanmar, is a location where Harlequin Shrimp have been observed

Underwater photographers relish the opportunity to capture the intricate behaviors of Harlequin Shrimp, a species known for their vibrant colors and unusual hunting tactics.
Divers seeking to document these captivating shrimp should be prepared for the challenge, as sightings are not always guaranteed.
To capture the elusive Harlequin Shrimp in action, a compact camera with a wet lens or a 60mm lens on a cropped sensor camera is recommended.
For a closer view, a 100mm/105mm lens is ideal, while fisheye lenses can offer an expansive background with careful positioning.
When photographing these delicate creatures, it's essential to maintain a respectful distance and avoid using harsh lighting, such as strobes, to minimize stress and ensure their welfare.
Harlequin Shrimp can be found in various destinations, including the tropical Indo-Pacific, the Hawaiian Islands, the Andaman Sea in Thailand, and the Mergui Archipelago in Burma/Myanmar.
Beyond their role in the underwater ecosystem, Harlequin Shrimp have become a popular subject in fashion-and-beauty, food-and-drink, home-and-garden, and travel photography.
In addition to facing challenges from aquarium collections for trade, Harlequin Shrimp are vulnerable to the effects of climate change, pollution, and overfishing, which threaten their coral reef habitats.
Responsible diving guides play a crucial role in protecting these fascinating creatures, educating divers about their importance and advocating for their conservation.
By preserving the natural behavior of Harlequin Shrimp and the ecosystem they inhabit, we can ensure the longevity of these inspiring underwater inhabitants and the enjoyment they bring to both marine biologists and casual observers alike.
As our understanding of Harlequin Shrimp and their ally, the muck divers who chase their captivating presence, continues to grow, so too does our appreciation for their role in the underwater world and the diverse lifestyles they represent.