Terebellides sp

(Note: This species keys to Terebellides stroemi Sars, 1835 in the Kozloff Key. Leslie Harris, a polychaete specialist at the LA Museum of Natural History, has informed me that T. stroemi does not actually occur on our coast so it is another, undetermined Terebellides species). My thanks to him for this correction.

Common name(s): 

Synonyms: Terebellides stroemi
Phylum Annelida 
Subclass Sedentaria 
Infraclass Canalipalpata 
Order Terebellida 
Terebellides sp from sandy mud at about 12 m depth in Burrows Bay near Rosario. Note the tuft of pink tentacles on the head (left) and the distinctive red gill of 4 partly-fused pectinate branches attached just behind the head. Total length 3 cm.
(Photo by: Dave Cowles, August 2018 )

Description:  Polychaetes from  family Trichobranchidae have segments mostly or completely as wide or wider than long. They have several to many long, threadlike, extensile unbranched tentacles closely associated with the mouth but that cannot be retracted into the mouth. One or more pairs of simple or branched gills are present behind the head region. The thoracic segments do not have soft pads on the ventral surface. The neuropodal uncini of the thoracic region have long handles. There is no distinct caudal region without setae, and the tube the animal may create is not stopped by an operculum. Terebellides stroemi has a distinctive single mid-dorsal gill near the anterior end with 4 partly fused, pectinate branches. All its tentacles are similar in shape and size. Note: Leslie Harris, a polychaete specialist at the LA Museum of Natural History, has informed me that T. stroemi does not actually occur on our coast so this specimen is another, undetermined Terebellides species). My thanks to him for this correction.

How to Distinguish from Similar Species:  Terebellidae is a sister family. Terebellids have soft, light-colored pads on the ventral surface of most thoracic segments and their neuropodal uncini have short handles. Other local Trichobranchids have 2-4 pairs of gills which are not pectinately branched and some of the tentacles are longer and more slender than others are. The mid-dorsal gill with 4 nearly fused pectinate branches near the anterior end in this species is truly distinctive. Terebellides kerguelensis is a very similar species off Antarctica that has a single dorsal gill of 5 partly fused, pectinate branches. 

Geographical Range:  Cosmopolitan, at least in the North Atlantic and North Pacific Oceans, Spitsbergen in the Arctic Ocean, and in the Baltic Sea. The type specimen is from off Norway.

Depth Range:  All the references I could find were subtidal.

Habitat:  Infauna in soft bottoms

Biology/Natural History:  The stomach of this species contains a 'digestive gland' involved both in secretion and absorption (Michel et al., 1984). Tentacles are used for feeding and gills for breathing (gas exchange). Note the bright red of hemoglobin in the gills.



Dichotomous Keys:
  Kozloff, 1987, 1996

General References:

Scientific Articles:

Bremec, C. S., and R. Elias, 1999. Species of Terebellides from South Atlantic waters off Argentina and Brazil (Polyghaeta: Trichobranchidae). Ophelia, 51(3), 177-186.

Hily, C., F. Le Loc'h, J. Grall, and M. Glemarec, 2008. Soft bottom macrobenthic communities of North Biscay revisited: long-term evolution under fisheries-climate forcing. Estuarine, Coastal and Shelf Science 78:2 pp 413-425. https://doi.org/10.1016/j.ecss.2008.01.004

Michel, C., M. Bhaud, P. Boumati, and S. Halpern, 1984. Physiology of the digestive gtract of the sedentary polychaete Terebellides stroemi. Marine Biology 83:1 pp 17-31

Williams, Susan J. (1984). The status of Terebellides stroemi (Polychaeta; Trichobranchidae) as a cosmopolitan species, based on a worldwide morphological survey, including description of new species. In Proceedings of the first international polychaete conference, Sydney, Australia (pp. 118-142).

Web sites:

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

Whole animal-tube
Another view of the whole worm, including part of the tube it had built. Note in all the photos the lighter-colored dots along the body, which appear to be eggs in the coelom. Photo by Dave Cowles, August 2018

Head closeup
A close-up of the head region. The tangle of tentacles appears yellow and the 4 partly fused gills are red. Scale is millimeters. Photo by Dave Cowles, August 2018

Head close-up
Another close-up of the head region. Note the eggs visible through the body wall and the first few eggs which are being extruded. Photo by Dave Cowles, August 2018

While being viewed, the animal began extruding many eggs from the anterior end. Photo by Dave Cowles, August 2018

For a movie scanning all the body regions click HERE.

For a movie close-up of the tentacles, gills, and extruded eggs click HERE.

Authors and Editors of Page:
Dave Cowles (2018):  Created original page
CSS coding for page developed by Jonathan Cowles

Salish Sea Invertebrates web site provided courtesy of Walla Walla University