Micrura verrilli Coe, 1901

Common name(s):  Verrill's Ribbon Worm

Synonyms:  Lineus striatus Micrura verrilli
Class Anopla 
Order Heteronemertea 
Family Lineidae 
Micrura verrilli, about 12-15 cm long, found under a rock on Sares Head
(Photo by: Dave Cowles, July 2011 )

Description:  As in other members of Class Anopla, this Nemertean has a mouth separate from the proboscis pore and the proboscis has no stylets.  Both the mouth and the proboscis are ventral on the head and posterior to the brain.  As with other members of  Order Heteronemertea, the head (cephalic lobe) has cephalic slits.  This species has no caudal cirrus (Morris et al. says it does but is often lost).  The body is soft, slender, and only slightly flattened.  The head (cephalic lobe) does not flare broadly and has no eyes.  Color is brown, lavender, or purple dorsally with distinct white transverse rings.  The head has a white border and a prominent orange dorsal triangle.  The ventral surface of the body is nearly white.  Up to 50 cm long and 4 mm wide.

How to Distinguish from Similar Species:  Micrura alaskensis has no transverse rings and the tip of the head is white. Micrura wilsoni has similar coloration but the head has the white border but not the orange triangle, plus its transverse white body stripes are irregularly spaced.

Geographical Range: Prince William Sound, Alaska to Monterey Bay, California

Depth Range: Intertidal and subtidal

Habitat: Usually under rocks or in eelgrass or surfgrass in relatively exposed environments.

Biology/Natural History:  This species inhabits a clear mucus tube which is sometimes almost papery and is often adhered to the underside of rocks.  It is usually uncommon but its strikingly beautiful colors make it memorable.  The species reproduces in spring and early summer.  It has extensive ability to regenerate body parts posterior to the brain.  Most Micrura species eat polychaetes and other nemerteans.

Verrill was a professor at Yale University who studied nemerteans.



Dichotomous Keys:
  Carlton, 2007
  Flora and Fairbanks, 1966
  Kozloff, 1987, 1996

General References:
  Kozloff, 1993
  Lamb and Hanby, 2005
  Morris et al., 1980
  O'Clair and O'Clair, 1998
  Ricketts et al., 1985

Scientific Articles:

Web sites:

General Notes and Observations:  Locations, abundances, unusual behaviors:


The head does not flare out broader than the body.  It has a white border and a prominent orange triangle on the dorsal side.  The underside is nearly white.

Authors and Editors of Page:
Dave Cowles (2010):  Created original page
CSS coding for page developed by Jonathan Cowles (2007)

Rosario Invertebrates web site provided courtesy of Walla Walla University