Overview

Comprehensive Description

Biology/Natural History: The tentacles are just in front of the brain and can be retracted. This animal is negatively phototactic. The margins of the body wrinkle as the animal moves (see photo above). Will eat mussel tissue in the laboratory. In Washington, gravid individuals can be found in March. 150-160 golden yellow eggs are laid individually in capsules, in a tight-packed monolayer or bilayer on rocks.

Creative Commons Attribution Non Commercial Share Alike 2.0 (CC BY-NC-SA 2.0)

© Rosario Beach Marine Laboratory

Source: Invertebrates of the Salish Sea

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

This giant flatworm has a band of eyespots along the entire margin of the body (may not be visible except in transmitted light), plus on its pair of short, blunt nuchal tentacles (picture), at the bases of the tentacles, and in the region of the brain. Its gut outline follows the multi-branching polyclad pattern. The color is tan with small spots or streaks of dark brown dorsally, lighter tan with few if any spots ventrally (picture). Has no suckers on the ventral surface.
Creative Commons Attribution Non Commercial Share Alike 2.0 (CC BY-NC-SA 2.0)

© Rosario Beach Marine Laboratory

Source: Invertebrates of the Salish Sea

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Distribution

False Narrows, Nanaimo, Vancouver Island, British Columbia, Canada
Collection date: prior to 1925
Kind: type locality
Comments: under stones at low water.

San Juan Island, San Juan County, Washington, United States
Collection date: 1933 or earlier
Kind: default type

Newport Harbor, Newport, California, USA
Collection date: 1953
Comments: specimens collected by Dr. MacGinitie.

Puget Sound, Washington, USA
Collection date: 1953
  • Bock S. 1925. index card avail.
     . Papers from Dr. Th. Mortensen's Pacific Expedition 1914-1916. XXV. Planarians. Parts I-III. Vidensk Medr dansk naturh Foren 79:1-84.
  • Freeman D. 1933.  abstract/note. The polyclads of the San Juan region of Puget Sound. Trans Am Microsc Soc 52:107-146.
  • Hyman LH. 1955. index card avail.
    abstract/note. The polyclad flatworms of the Pacific coast of North America: additions and corrections. Am Museum Novitates 1704: 1-11.
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© National Science Foundation - Turbellarian Taxonomic Database

Source: Turbellarian Taxonomic Database

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Geographical Range: Sitka, Alaska to Newport Harbor, CA

Creative Commons Attribution Non Commercial Share Alike 2.0 (CC BY-NC-SA 2.0)

© Rosario Beach Marine Laboratory

Source: Invertebrates of the Salish Sea

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Physical Description

Look Alikes

How to Distinguish from Similar Species: This species if far larger than any other species in this area, and is one of the largest in the world. Most other flatworms in this area are up to only about 3 cm long. Polyclads are the only group of flatworms in our area that get larger than microscopic size.
Creative Commons Attribution Non Commercial Share Alike 2.0 (CC BY-NC-SA 2.0)

© Rosario Beach Marine Laboratory

Source: Invertebrates of the Salish Sea

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Ecology

Habitat

Depth range based on 1 specimen in 1 taxon.
Water temperature and chemistry ranges based on 1 sample.

Environmental ranges
  Depth range (m): 0 - 0
  Temperature range (°C): 10.151 - 10.151
  Nitrate (umol/L): 6.725 - 6.725
  Salinity (PPS): 31.893 - 31.893
  Oxygen (ml/l): 6.561 - 6.561
  Phosphate (umol/l): 0.943 - 0.943
  Silicate (umol/l): 15.658 - 15.658
 
Note: this information has not been validated. Check this *note*. Your feedback is most welcome.

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Depth Range: Mid-intertidal to subtidal.

Habitat: Among mussels and under rocks, sometimes on pilings or on boat bottoms among fouling organisms.

Creative Commons Attribution Non Commercial Share Alike 2.0 (CC BY-NC-SA 2.0)

© Rosario Beach Marine Laboratory

Source: Invertebrates of the Salish Sea

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Disclaimer

EOL content is automatically assembled from many different content providers. As a result, from time to time you may find pages on EOL that are confusing.

To request an improvement, please leave a comment on the page. Thank you!