Migidae

Migidae is a family of spiders, sometimes referred to as tree trapdoor spiders or microtrapdoor spiders. They are characterized by their small size, typically ranging from 2 to 8 millimeters in body length, and their construction of small, camouflaged trapdoors in soil or on trees.

Description:

Migidae spiders possess a distinctive morphology that includes a robust cephalothorax and abdomen. Their legs are relatively short and stout, equipped with claws that aid in climbing and digging. The carapace is usually heavily sclerotized (hardened) and often ornamented. They are typically brown or black in color, providing effective camouflage. A key identifying feature is the presence of a rastellum on the chelicerae (jaws), a structure of stout spines used for digging and constructing burrows.

Distribution and Habitat:

Migidae spiders are Gondwanan relicts, meaning their distribution reflects the ancient supercontinent of Gondwana. They are found in South America, Africa, Madagascar, Australia, New Zealand, and New Caledonia. This widespread distribution across the Southern Hemisphere provides evidence of their ancient lineage. They inhabit a variety of habitats, including rainforests, woodlands, and even some drier environments, typically constructing their trapdoor burrows in the soil, on tree trunks, or among leaf litter.

Behavior and Ecology:

Migidae spiders are ambush predators. They construct trapdoor burrows, lined with silk, with a hinged lid camouflaged with surrounding materials like soil, leaves, or moss. They wait beneath the trapdoor, sensing vibrations from passing prey, such as small insects and other invertebrates. When prey approaches, the spider rapidly opens the trapdoor and seizes its victim.

Males of some Migidae species are known to disperse from their burrows in search of mates, while females typically remain in their burrows throughout their lives. Mating behavior is often poorly understood in this family.

Taxonomy:

The family Migidae belongs to the infraorder Mygalomorphae, which includes other groups of spiders with paraxial chelicerae (fangs that move up and down). The taxonomy of Migidae is subject to ongoing research and revision, and the number of genera and species recognized within the family can change as new discoveries are made and phylogenetic relationships are clarified. Several genera are recognized, including Migas, Mallecomigas, Calathotarsus, and others.

Conservation Status:

The conservation status of many Migidae species is currently unknown due to a lack of comprehensive surveys and research. Habitat loss and degradation, particularly deforestation, pose a significant threat to some populations, especially those with restricted geographic ranges. Further research is needed to assess the conservation needs of these fascinating spiders.