White Sea Urchin

"Similar in general shape to Strongylocentrotus droebachiensis but with fewer spines." (Lambert, Austin 2007)

"Most studies indicate an omnivorous diet. On the Grand Banks off Newfoundland gut contents were single-celled benthic organsisms, such as foraminiferans and diatoms, and the remains of various animals such as barnacles, bryozoans, hydroids and amphipods." (Lambert, Austin 2007)

How to Distinguish from Similar Species: S. droebachiensis is similar size and only a slightly darker green hue. However, S. droebachiensis has tube feet darker than the spines, and usually purple. The spines of S. droebachiensis have ridges with rounded surfaces and with periodic, somewhat fan-shaped sculpturings.

Known to occur on both sandy/shell hash bottoms and in rocky areas.

Depth Range: Strictly subtidal, and usually deeper than 30 m

This pale urchin also usually has very light tube feet. Spines are whitish or pale yellowish-green. Spines have ridges with nearly flat surfaces and no obvious sculpturing. Strictly subtidal, usually deeper than 30 m.

Biology/Natural History: Deep-living. May harbor the intestinal rhabdocoel flatworm Syndisyrinx franciscanus. We find this species on sandy/shell hash bottoms in the San Juan Channel at about 100-120 m depth.

Geographical Range: . Probably pan-Arctic. This and S. droebachiensis are the only species of urchin in the Puget Sound area that are also found in the NW Pacific off Russia.

Strongylocentrotus pallidus or Pale sea urchin is a species of sea urchin found in rocky areas in Norway, off Russia from the Barents Sea down to the central part of the Sea of Japan.

Echinopluteus larva. February to May

southern Gaspe waters (Baie des Chaleurs, Gaspe Bay to American, Orphan and Bradelle banks; eastern boundary: eastern Bradelle valley); South slope of Anticosti Island

From low intertidal to more than 200 m depth, on shell or gravel grounds, S. pallidus tends to live within the gravel whereas S. droebachiensis remains on the surface; Orkeny and Shetland

circalittoral of the Gulf and estuary

Mortensen (1943: p. 200) considered Toxopneustes pallidus G.O. Sars, 1871 as a junior subjective synonym of Strongylocentrotus droebachiensis (O.F. Müller, 1776).