-
Banded Sea Urchin, Echinothrix calamaris
-
Coelopleurus exquisitus is known only from around New Caledonia.
-
A close-up of part of the test of Calveriosoma gracile, showing the pores where the animal's tube-feet extend from.
-
The body of Calveriosoma gracile, like other sea urchins, has a 5-fold symmetry
-
The aboral side of the shell (test) has the off-centered petalidium, as seen clearly here in a dead specimen which has lost its spines. Note also that, unlike urchins which have 5, sand dollars have only 4 gonopores, visible around the star-shaped pattern in the center.
-
The oral (under) side of the test is flat. It has the mouth in the middle, with tracks leading to it. The anus is near the edge of the shell (at the bottom in this photo).
-
Although no external ridges are visible around the mouth from the outside (see previous photo), this broken piece shows that 5 radiating ridges around reinforce the test on the inside. Photo by Dave Cowles, July 2010.
-
Live Dendraster excentricus on sand in an aquarium at Shannon Point Marine Center. Found subtidally in Bellingham Bay. Diameter 6 cm. (Photo by: Dave Cowles, August 2006)
-
View of S. pallidus underside. Photo by Dave Cowles, Rosario, Jul;y 2000
-
Strongylocentrotus pallidus, about 8 cm diameter, captured at 110 m depth in San Juan Channel (Photo by: Dave Cowles, July 2000)
-
Strongylocentrotus droebachiensis Green Sea Urchin These three S. droebachiensis were found on a dredge in Friday Harbor Photo taken by Heidee Leno. July 2002
-
-
Strongylocentrotus purpuratus (left) is much smaller than its relative Strongylocentrotus franciscanus (right), and has shorter spines. Photo by Dave Cowles, July 2005
-
The spines of S. purpuratus are only about 2 cm or less long, as contrasted with the longer spines of S. franciscanus.
-
This view shows the intricate network of plates and openings on the aboral side of the urchin. The periproct plates in particular are weakly held together and often collapse after the animal dies. The 5 gonopores are located in 5 genital plates arranged around the periproct. One of the genital plates is also the madreporite. Clicking the image will take you to a larger, unlabeled version. Photo by Dave Cowles, Oct 2012.
-
-
This species is often found within holes they grind in rock (probably over multiple generations) with their teeth and spines. They may even erode holes in steel pilings by flaking off rust. The photos above and below were taken at Little Corona del Mar, CA by Dave Cowles, March 2005
-
The species often covers itself with rocks and algae, which it holds onto with its tube feet, as seen in this tidepool at Dana Point, CA Photo by Dave Cowles, March 2005
-
These individuals in a Cape Flattery tidepool have covered themselves with fragments of shells and dead barnacles. Photo by Dave Cowles, July 2010
-
Strongylocentrotus purpuratus, Little Corona del Mar, CA (Photo by: Dave Cowles, March 2005)
-
Foto Fitis, www.fotofitis.nl
Ecomare
Green sea urchins; Levende zeeboontjes.
-
Sea potato; Zeeklit.
-
Green sea urchin; Zee-egel.
-
Eccentric Sand Dollar (Dendraster excentricus), Ganges Harbour, Salt Spring Island, British ColumbiaSource: http://en.wikipedia.org/wiki/File:Eccentric_sand_dollar.jpg