Munididae Family of Squat Lobsters

Two Squat Lobsters of the Munidae Family can be found in this website:

Phylogeny: Squat Lobsters of the Munididae Family are in the phylum Arthropoda. They are in the subphylum Crustacea, the superclass Multicrustacea, the class Malacostraca, the subclass Eumalacostraca, the superorder Eucarida, the order Decapoda, the suborder Pleocyemata, the infraorder Anomura, and the superfamily Galatheoidea. The Munididae Family is one of seven families in this superfamily. The Munididae Family contains forty-two genera and over four hundred species.  This family is undergoing regular taxonomic revision. The meaning of the name Munididae  is debated. Some sources think it came from a Latin word meaning “protected”, referring the the spiny carapace.

Morphology: Squat Lobsters are 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. Munidid Squat Lobsters are characterized by having short spines along the front edge of their  thick carapace. They have 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, crayfish and shrimp, 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. Most species are reddish to brown in color. Munidid Squat Lobsters reach a maximum of 10 cm (3.9 inches) in length.

Habitat and Distribution:  Munidid Squat Lobsters are found in a variety of marine environments, in a variety of habitats, from deep sea thermal vents to open water. They may be benthic or pelagic. They are found from the sea surface to depths up to 1,500 m (4,920 feet).Munidid Squat Lobsters are found worldwide in tropical to temperate seas. At least  thirteen species from this family are found in Mexican waters.

Reproduction: Munidid Squat Lobsters are gonochoric (male or female for life). Reproduction is sexual with indirect external fertilization. Mating is accomplished by the transfer of a sperm packet from the male to the abdomen of the female. The female scratches open the sperm packet as she releases her eggs. The female carries the fertilized eggs on her abdomen until they hatch after a few weeks. The eggs hatch into planktonic larvae. After several developmental stages the larvae molt into benthic juvenile lobsters.

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