Euclymene zonalis (Verrill, 1874)

Common name(s): Bamboo worm

Synonyms: Praxilla zonalis
Phylum Annelida
Class Polychaeta
Order Capitellida
Family Maldanidae
Euclymene zonalis collected from mud at 120 m depth near Yellow Island, San Juan Channel.  The animal is 18 cm long and 0.5-1 cm diameter.  The head is at the lower end in the photo and the view is of the left side.  There is an injury partway back on the body.
(Photo by: Dave Cowles, July 2007)
Description:  As with other members of family Maldanidae (bamboo worms), this species has segments which are mostly longer than wide.  The first setigers are clearly demarcated from each other.  This individual has 15 setigers plus the prostomium/peristomium.  It has a cephalic plate on the prostomium (photos).  The cephalic plate has a conspicuous, leathery rim in which the lateral notches are not prominent (photos).  Setiger 1 is clearly demarcated from the prostomium/peristomium and has several capillary notosetae and a few modified uncini for neurosetae (photo).  The neuropodia of the first 3-4 setigers have only a few setae, and these are modified uncini (photo).  Many of the segments have ringlike folds in the skin.  The glandular rings around setigers 5 and after are not prominent.  The last several segments all have setae.  The anus is central on a funnel-like projection from the posterior end of the pygidium (photo).  The cirri around the pygidial funnel are all about the same length.

How to Distinguish from Similar Species: Euclymene sp has distinct notches in the rim of its cephalic plate, but it may merely be a variation of E. zonalis.  Many members of the family have no setae on the last several segments, or have prominent collars around some of the segments.

Note:  Thanks to Leslie Harris, a Polychaete specialist , I have learned that Eyclymene zonalis is probably not the species on our Pacific coast.  The actual species name is uncertain.

Geographical Range:  OBIS records include specimens from the Pacific Northwest and British Columbia coasts and from the New England states and Nova Scotia

Depth Range:

Habitat:  This family is often found in tubes on sandy/muddy beaches, often projecting from the sand.  This individual was subtidal on soft bottom.

Biology/Natural History:



Dichotomous Keys:
  Kozloff 1987, 1996

General References:

Scientific Articles:
Type the article information within this span 

Web sites:

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

Various photomicroscopic views of Euclymene zonalis' head
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In this nearly ventral view the mouth can be clearly seen.  Note that setiger 1 is clearly distinct from the prostomium/peristomium and from setiger 2, and that its notosetae are capillary setae. This lateral view clearly shows the cephalic shield dorsal to the mouth.  The shield has a raised, leathery rim which does not have large, distinct lateral slits in it. This dorsal view of the head shows the cephalic shield.


Views through the dissecting microscope of the setae on the first few segments:
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This is a view of the setae on setiger 1.  Dorsal is upward and anterior is to the left.  There is a tuft of several capillary notosetae but few if any neurosetae. This is a view of the setae on setiger 2, in the same orientation.  There is a tuft of capillary notosetae (top).  There are a few small uncini for neurosetae (in bottom slit).

The anus is on a conelike projection from the pygidium.  The last several segments have setae.  In this photomicrograph, the notosetae of the last segment are capillary and the neurosetae are uncini.

Authors and Editors of Page:
Dave Cowles (2007):  Created original page
Jonathan Cowles (2007):  Updated page with CSS