Harlequin Shrimp

Family: Palaemonid Shrimps (Palaemonidae)

Size: 2.5 - 5 cm (1 - 2 in)

Depth: 1 - 20m (3 - 65ft)

Distribution: Eastern and Central Pacific Ocean (its sister species H. elegans is found in the Indo-Pacific).

Identification: Finding this incredible creature is a rare and amazing experience for any diver.

• Color & Shape: The body is white, covered with distinctive red and purple blotches. The first pair of legs are modified into large, flattened, petal-like claws (chelipeds) used to hunt. On its head, it has specialized "petal-like" sensory antennules to smell out prey.
• Male vs. Female: Females are generally larger, have colored abdominal plates under the tail, and feature visible blue tips on their swimming legs (pleopods).

Behavior: A shy but fierce starfish hunter.

• Diet: They are highly specialized nocturnal predators that feed almost exclusively on sea stars (and occasionally sea urchins if starving). Working together, a pair will skillfully flip a slow starfish onto its back, eating the tube feet and soft tissues.
• Pair Bonding & Habitat: Shy and mild-tempered, they prefer to hide in dark crevices. They are monogamous and pair-bonding, meaning they stay together for life. Once they establish their nest in a rocky hole, they can remain in the exact same spot for months or even years.
• Reproduction & Defense: Females aggressively tend and aerate up to 5,000 eggs per season. Studies suggest they may retain toxins from their prey, making them potentially dangerous to predators. While "Not Evaluated" by the IUCN, their highly specialized diet and reliance on fragile coral reefs make them vulnerable to habitat loss.