Myxicola infundibulum (Renier, 1804)

Common name(s): Slime tube worm, slime feather duster

Synonyms:Terebella infundibulum M infundibulum colony
Phylum Annelida 
Order Sabellida 
A colony of Myxicola infundibulum on the side of a dock.  The colony is about 30 cm across and each funnel-like set of radioles is about 2.5-3 cm across.  The entire colony is a ball of mucus that remains when the animals withdraw rapidly into their slime tubes.
(Photo by:  Dave Cowles, July 2014)

Description:  Like all members of Family Sabellidae (parchment tube worms), this species has a plume of pinnate, featherlike radioles on its head region and lives in a flexible, leather or parchment-like tube it has secreted.  Like serpulids (calcareous tubeworms), the head has a series of pinnate  radioles with which the animal suspension feeds.  Unlike serpulids, the radioles are not spiraled but form a series of semicircles around the head region.  In Myxicola infundibulum none of the radioles have conspicuous ocelli curled around them near their tips (The do, however, have ocelli, as demonstrated by their rapid withdrawal into their tube when a shadow passes over them).  Unusually, the proximal part of the radioles are connected to one another by a membrane so that they form a funnel (photo).  The thorax is longer than in most local sabellids--8 setigers (setae-beaering segments).  The first 5 or 6 thoracic neuropodia have long-handled uncini (not avicular uncini) and no pickaxe-shaped setae.  The abdominal uncini occur in rows that extend much of the way around the segments and they have several apical teeth.  They secrete gelatinous tubes of mucus.  The color of the plume of radioles is yellow to greenish, brown, or brownish-purple.  Worm is up to 9 cm long.

How to Distinguish from Similar Species:  The membrane which connects the base of the radioles, forming them into a funnel, is a distinctive feature of this species when combined with abdominal uncini which form bands nearly around the body.  A second, related slime-tube worm, M. asthetica, has also been reported to be in the region. It has only 1-4 thoracic setigers and a single apical tooth on the abdominal uncini, and it often attaches to ropes.

Geographical Range:  Pacific coast of North America from the Bering Sea to California and in the Atlantic ocean.

Depth Range:  Intertidal to 425 m.

Habitat:  In rock crevices or on floats.  Sometimes buried in soft mud.

Biology/Natural History:  These worms are often found as an aggregation in which the individual members secrete so much slime that they make a boulder-shaped colony.  They withdraw rapidly into the clear mucus tubes when disturbed or when a shadow passes over.  Silt and small debris may cover the mucus, masking its transparency (photo).  At other times, they build their mucus tubes wedged between other species of worms, mussels, or tunicates.

This species can withdraw into its mucus tube very rapidly, by use of a giant ventral axon.  That axon extends throughout the length of the body and has been the subject of much research on neural activity.  It comprises 27% of the animal's entire nervous system.  Nerve impulses travel at 6-20 m/s along the axon.  The quick withdrawal into the tube not only shelters the worm from predators but forcefully ejects wastes from the tube.

Unlike in some other sabellids, the crown of radioles is not autotomized to escape predators, and if the animal loses its radioles it will likely die.

The name 'Myxicola' means 'living in slime' and 'infundibulum' refers to the funnel shape formed by the radioles.



 

References:

Dichotomous Keys:
  Kozloff, 1987, 1996

General References:
  Gotshall, 1994
  Harbo, 2011
  Kozloff, 1993
  Lamb and Hanby, 2005
  Morris et al., 1980

Scientific Articles:
 

Web sites:


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


Slime tube
A view of the animal partly retracted into its slime tube


Full view
When removed from the tube, this individual is about 6 cm total length.  Note that the animal has immediately begun to produce a new mass of mucus around itself.


Funnel
The radioles of this species are united through much of their length into a distinctive funnel.


Thorax
The thorax has 8 segments, the first 5 or 6 of which (at least) have long-handled uncini and no pickaxe-shaped setae.


Abdomen
The abdominal uncini form rows that go nearly all the way around the animal.


Authors and Editors of Page:
Dave Cowles (2014):  Created original page
CSS coding for page developed by Jonathan Cowles (2007)

Salish Sea Invertebrates web site provided courtesy of Walla Walla University