Eunice valens (Chamberlin, 1919)

Common name(s): Iridescent tubeworm, white-banded bobbit worm
Synonyms:  Eunice valens
Phylum Annelida 
Subclass Palpata 
Order Aciculata 
Suborder Eunicida 
Eunice valens, found intertidally in Padilla Bay by Sara Goodwin.  Total length about 15 cm.
(Photo by:  Dave Cowles, July 2009)
Description:   As a member of Family Eunicidae (a large family), this species has few if any segments longer than wide, the notosetae do not extend nearly to the midline, the prostomium does not form an elongated caruncle which extends posteriorly over several segments, The head (prostomium) has a pair of stout, globular prostomial palps, which are not differentiated into two segmentlike units.  The prostomium has 3 or 5 prostomial antennae but does not have a cluster of tentacles around the mouth.  The proboscis cannot be everted.  The pharynx has a pair of black ventral mandibles and 2 or more rows of black dorsal teeth, two of which are elongated and can be used as pincers.  The peristomium usually has tentacular cirri. Eunicids are usually brightly colored. Eunice valens has 5 prostomial antennae which have only faint (not strongly indented) annular articulations (photo).  A pair of dark dorsal eyes also is also found on the prostomium.  A short, dorsal pair of tentacular cirri is found on the peristomium (photo).  The first gills are on setiger 3, and are attached to the dorsal edge of the parapodium (neuropodium).  Each segment has up to 16 gill filaments on each side.  The filaments are short on anterior segments (photo) but are longer and overlap much of the dorsal part of the body farther back on the body (photo).  It has small yellow hooded hooks ventral to the aciculae.  The parapodia have neuropodia but no notopodia.  The dorsal surface of the body is purplish red and may be iridescent, and often has white stripes or patches, especially the distinctive band behind the head.  The ventral surface is lighter.  Length up to about 20 cm.

How to Distinguish from Similar Species:Eunice aphroditois has gills first appearing on setiger 5-7 and the hooks ventral to the aciculae are black.  The prostomial antennae have well-indented annular rings.  The Kobe bobbit worm, Eunice kobiensis, is very similar to E. valens but it is not known if E. kobiensis occurs in our area.

Geographical Range:  Alaska to central California

Depth Range:  Low intertidal to 15 m

Habitat:  Intertidal, usually in tubes under rocks.

Biology/Natural History:   Although this is an "errant" (motile) polychaete, it builds a parchmentlike tube which has adhering pebbles, usually under boulders.  This species is omnivorous, and ventures outside its tube to eat algae as well as other animals.

Reproduction in the Washington area takes place during spring and summer.  During reproduction, the rear portion of the body of  a number of species of Eunice breaks off as an independent, gamete-bearing individual called an epitoke which swims through the water releasing the gametes, while the anterior portion of the worm remains on the bottom.  However, in this species the adults do not become anatomically specialized during reproduction.  Females release yellow eggs about 1/3 mm in diameter.

Eunicids are the only polychaetes eaten regularly by humans (the Palolo worm Eunice viridis in Samoa and Fiji).  The palolo worm has an epitoke which swarms during the last quarter of the moon and the lowest tides during October and November.  Islanders gather the swarming epitokes for food.
 

This family builds only fragile parchment tubes if any.


 
 
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References:

Dichotomous Keys:
  Carlton, 2007
  Kozloff, 1987, 1996

General References:
  Lamb and Hanby, 2005
  O'Clair and O'Clair, 1998

Scientific Articles:

Web sites:

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

Head
This view of the head shows the 5 prostomial antennae with annular markings, plus the two peristomial cirri.


Gills behind head
This view shows that the gills start close behind the head, on setiger 3.


Gills
This dorsal view of the midregion of the body shows the gills and parapodia.
 
 
 
 
 


Authors and Editors of Page:
Dave Cowles (2009):  Created original page
CSS coding for page developed by Jonathan Cowles (2007)