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.”

Actinotroch of Phoronis vancouverensis

From Invertebrate Embryology blog

Caption: “These pictures are stacks of confocal images of two different actinotroch larvae of the horseshoe worm Phoronis vancouverensis (Phylum Phoronida). P. vancouverensis is a rather inconspicuous phoronid which lives in small (a few centimeters long) muddy tubes in clumps, attached to some sort of hard substratum (a rock, a floating dock) often in somewhat muddy surroundings. This species broods its larvae in the crown of tentacles, called the lophophore. I gently shook the larvae out of the lophophore of an adult and prepared them for confocal microscopy with my students while teaching the Comparative Embryology course at the Friday Harbor Labs in the Summer 2007.

We preserved the larvae and stained them with fluorescent phallodin (a toxin, derived from the deathcap mushroom Amanita phalloides), which binds to filamentous actin. Muscles are highlighted because they are full of actin, a protein which enables cellular contractility. So, most of what you see on these pictures are muscle fibers. There is also quite a bit of actin in the cell cortex (the region of the cytoplasm adjacent to the plasma membrane). So, the outlines of epidermal cells are often also labeled with phalloidin.”

Terrifying (but tiny!) bryozoans

Images 1 and 2: Beania mirabilis (source) cc-by-nc-sa

Image 3: Electra monostachys (source) cc-by-nc-sa

Image 1: “Scanning electron microscope image of a bryozoan colony” (Source)

Image 2: “This skeleton of a living bryozoan, collected at Bahia de los Angeles, Baja California, clearly shows this typical colonial organiation.

Each individual, or zooid, is enclosed in a sheath of tissue, the zooecium, that in many species secretes a rigid skeleton of calcium carbonate. Each zooid in this electron micrograph is less than a millimeter long and has a single opening, the orifice. Through this opening, the lophophore, a ring of ciliated tentacles centered on the mouth, protrudes to capture small food particles. The lophophore can be retracted very rapidly by specialized retractor muscles, and the opening closed by a doorlike operculum, visible on some of the zooids in the picture at the left.”


Image 3: Membraniporella nitida (source) cc-by-nc-sa

More info:

More brachiopods! The spiral lophophores are a filtering apparatus. 

Image 1: “Fig. 8. Hypothetical representation of efficiency of the filtering system of some extinct spire-bearing brachiopods showing flow patterns and extension of area for trapping food resources. Inhalant and exhalant currents according toVogel (1975) and diagram modified from Ager and Riggs (1964).”

Image 2: “Fig. 9. Hypothetical representation of efficiency of the filtering system present in extinct productid brachiopods showing flow patterns and extension of area for trapping food resources. Inhalant and exhalant currents as in a similar model proposed for Falafer Grant (1972) and diagram modified from Brunton et al. (2000) without including his interpretations.”


Pérez-Huerta and Sheldon. 2006. “Pennsylvanian sea level cycles, nutrient availability and brachiopod paleoecology.” Palaeogeography, Palaeoclimatology, Palaeoecology. Volume 230, Issues 3–4, 30 January 2006, Pages 264–279.

More brachiopods! The spiral lophophores are a filtering apparatus. 

Image 1: Brachiopod, (image source)

Image 2: Magellania, an articulate brachiopod (source)

Image 3: Group of brachiopods. (Source). The coolest one is “E”:

Notosaria nigricans E. Brachial interior with spirolophous lophophore 


Sounds like we have a word (or phrase) of the day!

Diagram by Edward Ott, Scholarpedia:

Figure 1: (a) Double well potential V(x) , and (b) the resulting basins of attraction.

The sea pig, Scotoplanes globosa — a deep-sea sea cucumber

Via Echinoblog:

Images 1 and 2: Via WikipediaLink 1; link 2. Lindberg, 1882, Report on the scientific results of the voyage of H.M.S. Challenger during the years 1873-76 : under the command of Captain George S. Nares, R.N., F.R.S. and Captain Frank Turle Thomson, R.N. (public domain)

image 3: (the shiny pink one — source)

Image 4: (the sinister-looking one — source)

Image 5: (the other pink one — source)

Image 6: (the toy — source)

Apparently it’s even been made into a toy by Agatsuma! Available on ebay.

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)

Caption: “Intercalation induces structural distortions. Left: unchanged DNA strand. Right: DNA strand intercalated at three locations (black areas).”

“In chemistryintercalation is the reversible inclusion of a molecule (or group) between two other molecules (or groups). Examples include DNA intercalation and graphite intercalation compounds.”

From the Wikipedia article on “Intercalation

(img source)

Moravec bush robots! A design for fractal branching ultra dextrous robots, proposed by Hans Moravec:

Image 1: Woefully unsourced! Clipped from a scanned PDF, more than likely… possibly from Mind Children by Hans Moravec?

Image 2Moravec, Hans; Easudes, Jesse; Dellaert, Frank (1999). “Fractal branching ultra-dexterous robots (Bush robots)”. NASA Advanced Concepts Research Project. PR-Number 10-86888.

(Wikipedia on Bush robots)