Images 1 and 2: Living pluteus larva of the sea biscuit Clypeaster subdepressus under polarized light microscopy. Only the skeleton remains visible. Photos by Bruno C. Vellutini (Wikimedia; Flickr); cc-by-sa

Image 3: Pluteus larva via ccNeLaS


Image 4: Developing pluteus larva. Via Wikimedia. Public domain

Image 5: Sea urchin development tattoo via The Loom

Caption: “Greetings! Here’s a pic of my science tat. I studied sea urchin development for my dissertation. Upon completion 2 yrs ago, I awarded myself this tat for my academic achievement. The tat is of a sea urchin egg, 2 cell embryo, blastula, gastrula, prism stage and pluteus larval stage. Or as my friend’s say, an orange developing into an Alien face-grabber.”

Image 1: Basket star (Astroglymma sculptum). Teresa Zubi, 2005 (source

Image 2: Giant Basket Starfish (Astrophyton muricatum) juvenile on Common Sea Fan (Gorgonia ventalina) Belize. Chris Newbert (source)

Image 3: Crystalline Entity encounters the Enterprise-D (comparison made in this excellent photoessay)

More info: http://echinoblog.blogspot.com/2010/01/gorgonocephalus-because-weird-is-what.html

Madreporites on sea stars

The madreporite is a lightcolored calcerous opening used to filter water into the water vascular system of echinoderms. It acts like a pressure-equalizing valve. […] Close up, it is visibly structured, resembling a “madrepore” (stone coral, Scleractinia) colony.” — Wikipedia

Image 1: Madreporites, from Pierce and Maugel’s 1987 Illustrated Invertebrate Anatomy (via “How Starfish Move”)

Image 2: Madreporite of Henricia pumila:The madreporite is creamy colored as in the type specimen.  Notice the papulae extended among the pseudopaxillae.” (Source)

Gorgonocephalus eucnemis, a species of basket star (starfish) from the Arctic

Photo by John Rix: http://www.flickr.com/photos/fathomthis/1795586640/

Basket Star reaching into the void (Gorgonocephalus eucnemis)

Queen Charlotte Strait, BC, 7 Tree Island, 2007

http://www.fathomthis.ca/simple_gallery/print_gallery.html

More info:

http://echinoblog.blogspot.com/2010/01/gorgonocephalus-because-weird-is-what.html

http://en.wikipedia.org/wiki/Gorgonocephalus_eucnemis

(I dressed up like a basket starfish last Halloween!)

Astropyga radiata (Diadematidae) – fire urchin, blue-spotted urchin 
http://en.wikipedia.org/wiki/Astropyga_radiata

I wonder if the spots are actually luminescent, or just highly reflective?

Photo 1: Geoffrey Bertrand (2011) link

Photo 2: Teresa Zubi (2005?) http://www.starfish.ch/Fotos/echinoderms-Stachelhauter/seaurchins-Seeigel/Astropyga-radiata.jpg

Photo 3: Source: http://www.siratus.com/article-voyage-plongee-jardin-sous-marin-contre-vases-tbt-de-la-trinite-42000672.html