Munidae Family of Squat Lobsters

Phylogeny:  Squat Lobsters of the Munidae Family and the Super Family Galatheoidae  being crustaceans that resemble lobsters in shape. They are more dorso-ventrally flattened than lobsters, and they hold their long tail curled up under their thorax, which gives them a squatting or crouching appearance. They are in the Phylum Arthropoda the Class Malacostraca and the Order Decapoda.

Distribution:  The Munididae Family are found worldwide in tropical and temperate seas and has more than two hundred forty species of which twelve are found along Mexico’s Pacific Coast. Squat Lobsters are found only in marine environments in a variety of habitats, from deep sea thermal vents to high altitude terrestrial caves and may be benthic or pelagic. They are found from the sea surface to depths up to 1,500 m (4,920 feet).

Morphology:  The Munidid are characterized by having short spines along the front edge of their  thick carapace and may or may not have a rostrum, two additional, longer spines over the eyes, and a central rostrum. They have 5 head segments, 8 thoracic segments, and 6 abdominal segments. The head and thorax are usually combined as a cephalothorax. The head includes a pair of antennae, a pair of antennules, and the mouth. These animals have a two chambered stomach. Squat Lobsters, like crabs, shrimp, and crayfish, are decapods, meaning they have five pairs of appendages that function as legs (pereiopods), three pairs that function as mouth parts (millipedes), and one pair that is modified into enlarged pincers (chalae). They also have three pairs of appendages that function as mouth parts (maxillipeds). Decapods, other than crabs, usually have six pairs of biramous (dividing to form two branches) appendages along their abdomen. The first five pairs function as swimmerets (pleopods). The last pair is flattened to form a tail fan. The Munidid reach a body length of approximately 10 cm (3.9 inches). Most species are reddish to brown in color.

Ecosystem Roles: The Munidid are suspension feeders and also algae grazers, detritivores, predators and scavengers. In turn they are preyed upon by a variety of predators including: sea birds, crustaceans, fish, octopus, pinnipeds, sea turtles, squid, and whales.