AT A GLANCE
- Common Name: Pacific Cleaner Shrimp
- Scientific Name: Lysmata amboinensis
- Category: Invertebrates
- Subcategory: Crustaceans
- Range: Circumtropical Indo-Pacific region, from the Red Sea and East Africa across the Indian Ocean to Japan, Hawaii, and French Polynesia
- Habitat Type: Coral reefs, rocky reef drop-offs, caves, overhangs, and coral bommies between 5 and 40 meters depth
- IUCN Red List Status: Not Evaluated (abundant across Indo-Pacific coral reefs)
- Lifespan: 2 to 4 years
- Diet: Carnivorous/Ectoparasite gleaner (gnathiid isopods, parasitic copepods, dead scales, and necrotic tissue cleaned from reef fish clients)
- Average Size/Weight: Total body length 5 to 6.5 cm; weight 5 to 12 g
- Key Defining Feature: Slender, golden-amber reef shrimp with a brilliant scarlet-red dorsal stripe split down the middle by an immaculate white line, and extremely long snowy-white sensory antennae
Overview
The Pacific Cleaner Shrimp (Lysmata amboinensis), also widely known as the Scarlet Cleaner Shrimp or Skunk Cleaner Shrimp, is one of the most famous, beneficial, and beloved mutualistic crustaceans on the world’s coral reefs. Belonging to the cleaner shrimp family Lysmatidae, this agile decapod operates dedicated ‘cleaning stations’ under reef overhangs. Bold and utterly fearless, it provides essential medical dental and skin hygiene services to reef fish—even walking directly inside the gaping mouths of predatory moray eels and groupers without being eaten.
Biology and Physical Characteristics
Lysmata amboinensis has an elongated, translucent golden-amber to bright yellow body. Running along the entire length of its back from the rostrum to the tail is an unmistakable, high-contrast racing stripe: a broad, vibrant scarlet-red band bisected down the middle by an immaculate, snow-white dorsal line. The tail fan (telson and uropods) is decorated with four distinct white spots on a red background. Projecting from its head are two pairs of extraordinarily long, whiplike, pure white antennae that are nearly twice the length of its body, used to signal and communicate with approaching fish clients. It possesses slender, delicate walking legs and tiny pincers (chelae) equipped with miniature tweezers.
Behavior and Ecology
Operating from a prominent coral ledge or cave entrance, the Pacific Cleaner Shrimp advertises its services by performing an unmistakable ‘cleaning dance’—swaying its body rhythmically from side to side while vigorously waving its long white antennae in the water column. Reef fish, from tiny damselfish to massive predatory apex predators like tiger groupers and giant morays, recognize the signal, pull up to the station, and adopt a trance-like pose with flared gills and open mouths. The shrimp hops aboard, scurrying across the client’s skin, fins, and teeth, carefully picking off parasitic isopods, fungal spores, and dead tissue with surgical precision.
Conservation and Human Impact
The Pacific Cleaner Shrimp has not been formally evaluated globally by the IUCN Red List. It is abundant across the tropical Indo-Pacific. However, because it is one of the most popular and commercially valuable invertebrates in the marine aquarium trade, heavy wild harvesting on localized reefs has raised calls for sustainable catch limits and expanded commercial captive breeding.
Interesting Factoid
The Pacific Cleaner Shrimp is the coral reef’s fearless dentist—it will happily crawl straight inside the razor-toothed mouth of a giant moray eel to pick parasites off its tongue, and the eel never eats it.