Sejus
C.L. Koch, 1836
Sejus is a of sejine in the Sejidae, superfamily Sejoidea. The genus contains approximately 17 described . Members of this genus exhibit a mixture of and derived characters typical of the Sejoidea, including hypertrichy, a distinctive female sterno-genital region, and a phoretic stage. Sejus species are generally distributed in warmer regions globally, though at least one species (S. americanus) extends into zones.
Pronunciation
How to pronounce Sejus: /ˈseɪ.dʒəs/
These audio files are automatically generated. While they are not always 100% accurate, they are a good starting point.
Habitat
Sejus tend to occur in warmer parts of the world, though S. americanus has been documented in forest at 56°N in Alberta, Canada. Specific microhabitat preferences for most species are not well documented.
Distribution
Global distribution with concentration in warmer regions; recorded from North America (including Canada), Europe, and other regions. GBIF records indicate presence in Norway and Sweden.
Life Cycle
Postembryonic development follows the standard mesostigmatid pattern: , , , , tritonymph, and . A phoretic deutonymph stage is present. involves quiescent periods with specific positioning prior to .
Behavior
involves quiescent periods where individuals become inactive before , with documented positioning behavior during the moult.
Similar Taxa
- ReginacharlottiaBoth are sejine in the superfamily Sejoidea; Reginacharlottia was erected based on unusual characters including a interdigital cheliceral excrescence and highly reduced female genital shield not found in Sejus.
- IchthyostomatogasterBoth belong to Sejoidea; Ichthyostomatogasteridae is distinguished from Sejidae by -level characters of the female genital and regions.
- UropodellaBoth are sejoid ; Uropodellidae differs in having reduced sclerotisation and other derived character states convergent with other Mesostigmata.
More Details
Reproductive system
Members of Sejoidea, including Sejus, possess an archispermous mating system.
Tarsal morphology
IV bears an intercalary with a pair of , a characteristic feature of the superfamily Sejoidea.
Sources and further reading
- BugGuide
- Wikipedia
- GBIF taxonomy match
- iNaturalist taxon
- NCBI Taxonomy
- Catalogue of Life
- Postembryonic development of Sejus togatus CL Koch, 1836 (Parasitiformes: Mesostigmata: Sejida) with notes on moulting behaviour
- <p class="SP77849">A new genus and family of sejine mites (Acari, Parasitiformes, Mesostigmata, Sejoidea) based on new species from Lord Howe Island and Brazil, and a redescription of Sejus americanus (Banks, 1902)