Serpula vermicularis Linnaeus, 1767

Common name(s): Calcareous tubeworm, Plume worm, Fan worm, Limy tube worm, Red tube worm
Synonyms:  Serpula columbiana
Phylum Annelida
 Class Polychaeta
  Order Sabellida
   Family Serpulidae
A large Serpula vermicularis on a rock picked up subtidally near Rosario.  Total tube length about 12 cm and nearly 1 cm diameter.
(Photo by: Dave Cowles)
Description:  Serpulids live in calcareous tubes, which often curve but are not strongly spiraled except perhaps in their earliest portion (photo).  Their anterior appendages include a crown of featherlike radioles (photo) which protrude from the peristomium.  Often the tube is sealed with an operculum (which is a modified radiole--photo) when the animal retreats inside.  Most segments are wider than long.  The thoracic region has more than 4 setigers.  This species has a well-developed, funnel-shaped operculum (photo).  The operculum has a ringlike thickening but no obvious protuberances just below the funnel.  The radioles are red, pink, or orange and are usually banded with white.  There are usually about 40 radioles in an adult.  The  operculum is shaped like a circular funnel and has up to 160 creases along its margin.  The operculum is usually red.  Sometimes the animal has more than one operculum.  The white tube can be up to 20 cm long but is usually smaller.  The tube is smooth or has longitudinal ridges, but no keel.  The animal's body is yellow and up to 8 cm long.  It has two eyes on the peristomium but none on the radioles.  The animal has 7 thoracic segments and the abdomen has up to 190 segments.

How to Distinguish from Similar Species:  This very common species is the only local serpulid with the reddish plumes and a funnel-shaped, symmetrical operculum with no protuberances.  It is also the only species of large serpulid found in our area.  Spirorbids are small and have a strongly coiled tube.

Geographical Range:  Cosmopollitan:  Pacific, Atlantic, and Indian oceans, Mediterranean Sea, North Sea.  Alaska to Baja California on our coast.  Although this species occurs in Europe, it is not found on the east coast of the United States.

Depth Range:  Intertidal to 100 m

Habitat:  Attached to the undersides of rocks in the intertidal, on floats, or on any surface of subtidal rocks.

Biology/Natural History:  This species has two white calcium sacs near the midventral line on the posterior end of the peristomium.  The sacs store calcium from a pair of glands which open on the "ventral shields" which are wide glandular pads on the ventral side of the anterior thoracic segments.  The ventral shields probably secrete organic material and use this, combined with the calcium, to form a paste from which the tube is made.  The tube appears to be shaped by the ventral shields and by a collar which is just behind the head.  The tubes are made of both calcite and aragonite.  The operculum is cartilaginous and secretes mucus, which seems to be both antibiotic and prevents fouling.  The blood of this species, as with most species of serpulids and sabellids, contains chlorocruorin.  Chlorocruorin has a very strong affinity for carbon monoxide--570 times as much as human hemoglobin has.  This may partly explain why this worm may settle on some seaweed such as Fucus but seems to avoid Nereocystis.  The pneumocysts of Nereocystis are inflated with carbon monoxide, which would probably be strongly toxic to these worms.  The circulatory system of this species is unusual.  It has a ventral blood vessel which moves blood posteriorly, but blood moves anteriorly through a sinus that surrounds the gut.  Blood flow into peripheral parts is tidal.

The animal is a filter feeder.  Predators include Pisaster ochraceous.  Sexes are separate.  Eggs and sperm are released into the water.

This is the "type species" for genus Serpula and Family Serpulidae.  Note that it was originally described by Linnaeus.  Serpulids feed by extending featherlike radioles, which also function as gills.  The blood circulation within the radiole is unusual.  Instead of having one-way flow through afferent and efferent vessels within the radiole, there is a single branchial vessel which blood flows in and out of.  Serpulids possess giant nerve fibers running down their body which allows them to retract rapidly into their tube if disturbed.


 
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References:

Dichotomous Keys:
  Flora and Fairbanks, 1966
  Kozloff 1987, 1996
  Smith and Carlton, 1975

General References:
  Carefoot, 1977
  Gotshall, 1994
  Harbo, 1999
  Johnson and Snook, 1955 (as Serpula columbiana)
  Kozloff, 1993
  McConnaughey and McConnaughey, 1985
  Morris et al., 1980
  Niesen, 1994
  Niesen, 1997
  Ricketts et al., 1985
  Sept, 1999

Scientific Articles:
 

Web sites:
 


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



Anterior appendages include the abundant radioles seen here.  Behind the radioles to the bottom left the lighter red, funnel-shaped operculum can be seen.



This tiny individual, with a tube less than 1/2 cm long, is attached to a bryozoan.  Note the coiling of the tube in tiny individuals such as this.  The funnel-shaped operculum is visible to the left of the radioles.
The gray, forklike object projecting down to the left from one of the coils is a tiny phoronid worm about 2 mm long.  Cilia on the worm's forked lophophore are beating strongly.


Authors and Editors of Page:
Dave Cowles (2006):  Created original page