Spirosperma ferox (Eisen)
Recognition
The dorsal bundles with hair and pectinate chaetae.
The dermis is densely papillate, opaque and encrusted unless newly shed.
The prostomium and first segment are retractile.
The anterior dorsal bundles have up to 7 sabre shaped hairs and 5 lyre
shaped pectinate chaetae.
The anterior ventral bundles have up to 7 bifid chaetae, those behind the
genital segments with the teeth diverging obtuse angle.
Summary
Formerly in Peloscolex.
A medium sized tubificid (15 - 40 mm)
Common and abundant in mesotrophic sites, but uncommon in oligotrophic and
grossly polluted sites.
Distribution
A holarctic species that is widespread in eastern North America.
13 APR 1996 D.L. Gustafson
AIM home page
dlg@rivers.oscs.montana.edu