Rhyacodrilus sodalis (Eisen)

Recognition

The dorsal bundles with hair and pectinate chaetae. Only mature worms can be identified to species. Coelomocytes are present in the species of this genus and Bothrioneurum vejdovskyanum, which lacks dorsal hairs. The anterior dorsal bundles have 1 or 2 hairs and 2 to 3 pectinate chaetae with long, parallel teeth. The dorsal chaetae in 8 and 9 have the distal tooth twice the length of the proximal tooth. Posterior dorsal bundles have 1 hair and 1 or 2 pectinate chaetae with shorter teeth. The 2 to 5 penial chaetae are simple pointed and blunt with curved tips and arranged in a fan-shaped bundle. There is no penis sheath.

Summary

A small tubificid (5 - 10 mm) that is uncommon and poorly known and it has variable chaetae.

Distribution

A holarctic species that is widespread in North America.

13 APR 1996 D.L. Gustafson
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dlg@rivers.oscs.montana.edu