Crucigera zygophora (Johnson, 1901) Common name(s): Yoke-bearer calcareous tubeworm
Synonyms:
Phylum Annelida  Class Polychaeta  Order Sabellida  Family Serpulidae
	Crucigera zygophora, attached to a rock. The tube is about 5 mm diameter and the plume is about 18 mm across.
	(Photo by:  Dave Cowles, July 2024)

Description:  As with other tubeworms from Family Serpulidae, this worm secretes a calcareous (made of calcium carbonate) tube which is rock-hard. It extends its head with feather-like radioles from the open end of the tube to feed, as seen here. Near the center of the spread of radioles (above them here) is a round, funnel-shaped operculum that is used to block the entrance to the tube to keep out any danger when the worm rushes inside. There are three rounded bulges on the operculum stalk.

How to Distinguish from Similar Species:Crucigera irregularis has an operculum that is not round and has only two bulges on the operculum stalk. Serpula columbiana has a ring around the operculum stalk instead of bulges. 

Geographical Range:  Alaska to central California

Depth Range:  Intertidal to 146 m

Habitat:  Attached to hard surfaces

Biology/Natural History:  This tubeworm is larger than most Serpulid tubeworms I have seen.

References:

General References:
  Lamb and Hanby, 2005

Scientific Articles:
 

Web sites:

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

Another view. Photo by Dave Cowles, July 2024

Authors and Editors of Page:
Dave Cowles (2024):  Created original page
CSS coding for page developed by Jonathan Cowles

Salish Sea Invertebrates web site provided courtesy of Walla Walla University