Microcina jungi

Jung's Micro-blind Harvestman

Family: Phalangodidae · Class: Arachnida · Order: Opiliones

Conservation status: G1 S1

Jung's micro-blind harvestman is a small arachnid in the order Opiliones, belonging to the family Phalangodidae. This species is classified within the suborder Laniatores and infraorder Grassatores, distinguishing it from other harvestman groups. As indicated by its common name, this species exhibits microphthalmic characteristics, having extremely reduced or absent eyes, an adaptation common among soil-dwelling arachnids in specialized habitats. Jung's micro-blind harvestman is endemic to California, with its known distribution limited to specific locations within the San Francisco Bay Area region. The species occurs in association with serpentine soil outcrops found in the Coast Ranges of California. According to the U.S. Fish and Wildlife Service, this species is known to occur within other California counties, though specific locality data remains restricted due to conservation concerns. The species inhabits serpentine soil grasslands, a specialized and rare habitat type characterized by dry, nutrient-poor soils derived from serpentine rock formations. These soils contain high concentrations of magnesium and heavy metals while being deficient in essential nutrients like nitrogen and phosphorus. The serpentine grasslands where Jung's micro-blind harvestman occurs are found within discontinuous rock outcrops in the Coast Ranges, creating isolated habitat patches that support endemic species adapted to these harsh soil conditions. As a member of the Laniatores suborder, Jung's micro-blind harvestman likely exhibits predatory behavior typical of this group, feeding on small invertebrates found in the soil and leaf litter. The reduced eyes suggest this species relies heavily on tactile and chemical cues for navigation and prey detection within its subterranean microhabitat. Specific details regarding reproduction, seasonal activity patterns, and life cycle duration have not been well documented for this species. Jung's micro-blind harvestman holds a global rank of G1, indicating it is critically imperiled with typically five or fewer occurrences or very few remaining individuals. The species also carries a state rank of S1 in California, reflecting its extremely limited distribution and vulnerable status within the state. It is on the CDFW's Special Animals List. The primary threat to this species is habitat conversion and fragmentation. According to the Recovery Plan for Serpentine Soil Species, conversion of habitat to urban and industrial uses has extirpated listed species and species of concern from the majority of their historic ranges in the greater San Francisco Bay Area. The remaining natural serpentine soil grasslands represent only a fraction of the original habitat extent. The species appears on the U.S. Fish and Wildlife Service species list, with historical candidate status dating to 1994 reviews. Current federal listing status remains under evaluation as of December 2025. Conservation efforts for Jung's micro-blind harvestman are incorporated within broader serpentine grassland habitat protection initiatives in the San Francisco Bay Area, focusing on preserving remaining intact serpentine soil communities and preventing further habitat fragmentation through development pressures.

Data from The California Species Project — 14,000+ California species with verified data from CNPS, CDFW, USFWS, and more.