Spirostreptidae

Spirostreptidae can be distinguished from other spirostreptid millipede families by gonopod morphology, particularly the structure of male copulatory appendages used in species-level taxonomy. Geometric morphometric analysis of gonopods has revealed significant intraspecific variation, complicating taxonomic assignment based solely on qualitative shape categories. Species identification typically requires examination of gonopod structure; molecular data (COI and 16S rRNA) may be necessary for definitive identification in some genera such as Sechelleptus.

Habitats range from tropical riparian forests and arboreal environments to desert ecosystems. The desert-dwelling species Orthoporus ornatus occupies subsurface soil in rocky hillside, sandy wash, and desert pavement habitats in Arizona, using vertical migration to exploit thermal gradients. The arboreal species Sechelleptus arborivagus inhabits trees on Mayotte Island. Urban populations of Urostreptus atrobrunneus have established in built environments in São Paulo State, Brazil.

Disjunct distribution spanning North and South America, eastern Mediterranean, continental Africa, Madagascar, and Seychelles. The genus Plagiotaphrus is distributed across Africa with likely broader occurrence than currently documented due to incomplete survey coverage.

Surface activity in desert species is constrained by temperature extremes, with movement occurring primarily during evening and morning hours when thermal conditions are moderate. In tropical species, surface activity patterns have been observed during specific breeding periods.

Aggregation behavior has been documented in multiple species. In Alloporus uncinatus, aggregations of 6-42 individuals are associated with feeding activities of immature stages rather than reproductive functions. Males of this species obtain mates through random encounters and by forming triplet associations with copula pairs; mating is size-selective, likely due to female choice. Active behavioral thermoregulation includes vertical migration in soil, microhabitat selection (burrows, rock crevices, under vegetation), and coiling responses to reduce surface area when exposed to high temperatures.

Soil macro-arthropods involved in maintaining ecosystem balance through detritivory. Population explosions may occur following environmental imbalances, climate changes, or pesticide applications that eliminate competitors.

Urostreptus atrobrunneus has become a synanthropic pest in urban centers of São Paulo State, causing problems for human populations; control efforts have been hindered by limited knowledge of its biology. The species' foregut and salivary gland morphology has been studied to inform management strategies.

• Other Spirostreptida familiesSpirostreptidae is distinguished from related families within Spirostreptida primarily by gonopod morphology; family-level assignment requires examination of male reproductive structures

• millipede
• diplopod
• soil fauna
• detritivore
• tropical
• desert
• thermoregulation
• aggregation
• synanthropic
• gonopod taxonomy

• BugGuide
• Wikipedia
• GBIF taxonomy match
• iNaturalist taxon
• NCBI Taxonomy
• Mating Tactics in the Tropical Millipede Alloporus Uncinatus (Diplopoda: Spirostreptidae)
• Aggregation in the tropical millipedeAlloporus uncinatus(Diplopoda: Spirostreptidae)
• Behavioural thermoregulation of Orthoporus ornatus (Diplopoda: Spirostreptidae) in three desert habitats
• Mating behaviour and mate choice experiments in some tropical millipedes (Diplopoda: Spirostreptidae)
• Structure and function of the foregut and salivary glands of the synanthropic diplopod Urostreptus atrobrunneus (Spirostreptidae)
• Geometric morphometric analysis of gonopods in Bicoxidens flavicollis populations (Diplopoda, Spirostreptida, Spirostreptidae)
• A review of the taxonomy and distribution of Plagiotaphrus Attems 1914 (Diplopoda, Spirostreptida, Spirostreptidae)
• A new species of Lophostreptus Cook, 1895 discovered among syntypes of L. regularis Attems, 1909 (Diplopoda, Spirostreptida, Spirostreptidae)
• Sechelleptus arborivagus sp. nov., a new arboreal spirostreptid millipede (Diplopoda, Spirostreptidae) endemic to Mayotte Island (Comoros Archipelago), Indian Ocean