Squat lobsters are not true lobsters, but they are masters of the deep sea

Nature · Published 3 October 2026 Swipe more like this →

In short: Despite their name, squat lobsters are more closely related to hermit crabs than their namesake. These flattened, long-tailed crustaceans thrive from shallow caves to deep-sea hydrothermal vents. Often sold as langostino, they serve as a vital trophic link in marine ecosystems, connecting primary producers to the ocean's top predators.

Squat lobsters are a diverse group of over 900 described species, characterized by their dorsoventrally flattened bodies and long tails tucked beneath their cephalothorax. While they resemble true lobsters, their morphology is an intermediate between lobsters and crabs. They belong to the infraorder Anomura, and recent genetic research has revealed that they are not a monophyletic group, meaning they do not share a single common ancestor. Instead, they are classified into two superfamilies, Galatheoidea and Chirostyloidea, which likely evolved independently.

These crustaceans are found worldwide, inhabiting environments ranging from near-surface waters to deep-sea hydrothermal vents and shipwrecks. Their behavior is as varied as their habitats. Some species, like Munida gregaria, form dense pelagic swarms, while others are benthic, often aggregating around three-dimensional structures like cold seeps or whale falls for protection and food. Interestingly, their aggressive interactions are generally low; studies on Munida quadrispina have shown that their social behavior can be chemically modulated, with serotonin increasing aggression and octopamine promoting escape responses.

The commercial value of squat lobsters is significant, particularly in Latin America, where they are harvested for human consumption and as feed for aquaculture. In El Salvador, for example, production of Pleuroncodes monodon peaked at 13,708 tonnes in 2005. Beyond their economic role, they are ecologically important as a direct trophic shortcut in the food web. Their evolutionary history is marked by rapid diversification during the late Oligocene and Miocene, with their center of diversity currently located in the Indo-Australian Archipelago, often called the coral triangle.

General information, not professional advice. Spotted an error? Flag the card or see corrections and complaints.

Intellect Plus is a visual educational discovery platform for exploring fascinating facts and ideas. Brain Food, Not Brain Rot. What is Intellect Plus?

Related

• These vibrant, shy crustaceans are the hidden jewels of the world's coral reefs
• These flattened crustaceans are not true lobsters, but they are masters of disguise.
• Why these fuzzy crustaceans are actually imposters within the spiny lobster family tree
• Why the spiny lobster is not a true lobster despite its name and appearance
• The New Zealand scampi is a primitive survivor of the deep ocean floor
• Why the stick mantis is a master of disguise, not a stick insect
• The Southern Hawker is a harmless, inquisitive giant patrolling your local garden pond
• Stingless bees are tropical powerhouses that produce medicinal honey and boost crop yields
• The hidden engineers of soil health are more than just microbes
• The twisted-wing insects that hijack their hosts from the inside out
• The snakefly is a living fossil with a neck that mimics a serpent
• These tiny soil-dwellers are the only arthropods that breathe through their heads

More in Arthropods · More in Nature · Latest · A–Z · All topics