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 Major Groups | Insecta (insects) | Coleoptera (beetles) | Sphaeriusidae


Major Group: Insecta
Order: Coleoptera
Family: Sphaeriusidae (formerly Microsporidae and Sphaeriidae)
Genus: Sphaerius (formerly Microsporus)
In Australia, this family contains a single aquatic genus, Sphaerius.

Descriptive Features:

  • antennae with distinct 3-segmented club
  • body shiny black, hemispherical
  • wings rolled apically
  • abdomen with only 3 ventrites
  • tarsi 3-segmented
  • size: minute, <1 mm 
  • antennae 2-segmented
  • labrum separated from head capsule by complete suture
  • mandibular mola present
  • maxillary palp 2-segmented
  • abdomen 9- or 10-segmented
  • abdominal spiracles 1-8 forming balloon-like tracheal gills
  • abdomen with a pair of small spiracular gills or tubercles on each of segments 1 - 8
  • abdominal segment 9 with paired processes, unsegmented, immovable
  • legs 4-segmented with 1 claw
  • size: <2mm

    Spaeriusidae larva


    Spaeriusidae adult

    Taxonomic Checklist: Species
    Sphaerius coenensis Oke
    Sphaerius ovensensis Oke

    S. coenensis
    S. ovensensis NSW, Vic

    Sensitivity Rating: SIGNAL grade 7 (as Microsporidae)

    Functional Feeding Group: shredders (adults), predators (larvae)


    tributary to Barron River, Kuranda Qld

    Ecology: Instream habitat: Sphaeriusid beetles are part of the interstitial fauna that lives in accumulations of gravel, sand and mud at the edges of streams and rivers
    Feeding ecology: Adults are herbivores feeding on algae. Larvae are predators. However both adults and larva may also be scavengers feeding on detritus
    Habit: Adult sphaeriusid beetles are minute and spherical. Larvae have eight pairs of balloon-like spiracular gills on the abdomen enabling them to breathe underwater.
    Life history:


    Information Sources: Lawrence & Britton 1991, Lawrence 1992, Lawrence et al. 2000, Mathews 1980, Lawrence et al. 2000, Jaech 2001
    Key to Species: none