Blaniulidae

Distinguished from other julid families by combination of extremely slender body form (length:width ratio up to 30:1), presence of ozadenes as segmental spots, and variable ocular development. Within Julida, the 30:1 length-to-width ratio exceeds that of most other families. Troglobitic species eyeless; epigean species typically with ocelli. Choneiulus palmatus specifically identified by single row of ocelli paralleling ventral head margin, 14-20 long setae on metazonite margins, and posterior gonopods with fringed funnel terminations. Separation from similar slender julids requires examination of gonopod structure and ozadene position.

Elongated, cylindrical millipedes with extremely slender bodies; length-to-width ratio up to 30:1. Each segment bears distinctive paired spots representing ozadenes (odiferous defensive glands). Head with variable eye presence: eyes may be present as a single row of ocelli paralleling the ventral margin, or completely absent in troglobitic species. Body composed of numerous segments with 2 pairs of legs per segment typical of Diplopoda. Some species with 14-20 long setae on dorsal and dorsolateral margins of metazonites. Posterior gonopods in males terminating in funnel with fringed margins in some genera.

Diverse: leaf litter at deciduous woodland edges, soil, caves, superficial subterranean habitats (mesovoid shallow substratum/MSS), ant nests, mole nests, under bark and in dead wood of old trees. Synanthropic populations in buildings, waste ground, churchyards, and cultivated areas. Native populations often associated with basic and calcareous bedrock. Some species exclusively subterranean; others occur in both epigean and hypogean habitats.

Native to western, central, and northern Europe with southernmost records in southern France and northernmost in northern Sweden. Atlantic zone of northwest Europe. Macaronesia (Madeira, Azores). Introduced to North America and Tasmania. Records from Algeria. Specific genera with restricted distributions: Acipes in Macaronesia and Iberian Peninsula; Cibiniulus in Slovakia; Thassoblaniulus in Albania.

Adults of Choneiulus palmatus collected February–June and September–November in British and Irish Isles. Postembryonic development documented over multiple years in Finnish populations. Seasonal patterns for other genera not documented.

Postembryonic development occurs over multiple years (documented in Finnish Choneiulus palmatus population). Adult presence seasonal in some species. Detailed developmental stages not described.

Defensive secretion from ozadenes when disturbed. Some species occasionally agricultural pests. Troglobitic species restricted to permanent darkness in caves and MSS habitats.

Decomposer in leaf litter and soil habitats. Ozadenes produce defensive secretions.

Choneiulus palmatus occasionally reported as agricultural pest. Synanthropic populations facilitate passive dispersal to new regions including North America and Tasmania. Subject of genome sequencing research (626.52 Mb chromosome-level assembly).

• Other Julida familiesBlaniulidae distinguished by 30:1 length-to-width ratio and ozadene presence; other julids generally less elongate
• JulidaeJulidae typically more robust with lower length-to-width ratios; gonopod structure differs

• millipede
• diplopoda
• julida
• decomposer
• cave-dwelling
• synanthropic

• BugGuide
• Wikipedia
• GBIF taxonomy match
• iNaturalist taxon
• NCBI Taxonomy
• Two new species of the millipede family Blaniulidae (Diplopoda, Julida) from caves in central and southeastern Europe
• The genus Acipes Attems, 1937 in the Iberian Peninsula (Diplopoda, Julida, Blaniulidae), with the description of three new species from Spain
• The genome sequence of the millipede, Choneiulus palmatus (Nĕmec, 1895) (Julida: Blaniulidae).