Subterranean-adaptation
Guides
Anapidae
Ground Orb-web Spiders
Anapidae is a family of minute spiders containing approximately 233 extant species in 59 genera, with most adults measuring less than 2 mm in body length. The family has undergone significant taxonomic revision, incorporating the former families Micropholcommatidae and Holarchaeidae as subfamilies. Members are primarily ground-dwelling inhabitants of moist forest habitats, where many species construct diminutive orb webs less than 3 cm in diameter. The group exhibits remarkable anatomical conservation despite extreme miniaturization, retaining complete organ systems and musculature that comparable-sized insects often reduce or lose.
Trechinae
Trechinae is a subfamily of ground beetles (Carabidae) containing over 6,700 described species across more than 430 genera and 6 tribes. The group exhibits remarkable diversity in habitat preferences, ranging from surface-dwelling species in alpine páramos and saline coastal environments to highly specialized troglobitic (obligate cave-dwelling) forms with extreme morphological adaptations including eyelessness and depigmentation. Notable tribes include Trechini, which contains the most morphologically modified cave-adapted species, and Pogonini, which are primarily associated with humid and saline environments.
Trogloneta
spurred orb-weavers
Trogloneta is a genus of minute spurred orb-weavers in the family Mysmenidae, described by Eugène Louis Simon in 1922. The genus currently comprises twelve described species distributed across Europe, East Asia, and the Americas. These spiders are among the smallest known spiders, with some species measuring less than 2 mm in body length. Several species exhibit cave-adapted characteristics and restricted distributions, with some Chinese species showing extreme population genetic divergence due to geographic isolation in karst cave systems.