"Sapphire of the Sea:" A Hexagonal Chitinous Invisibility Cloak on This Critter

     The hexagonal chitinous invisibility cloak of the Sapphirina or "Sapphire of the Sea" 

allows it to change from deep violet-indigo colors to blue-green to

 all colors of the spectrum to nearly completely invisible.

        This exquisite ability is due, in part, to the hexagonal plates on its surface (here seen under a Scanning Electron Microscope (SEM)):

      The male of this parasitic copepod species shine their colors while the females are mostly translucent all the time. This structural coloration, first described by Isaac Newton and Robert Hooks, allows the intense and varied bright colors (as seen in peacock feathers).

     The Sapphirina reminds me a bit of our old friend the water bear or Tardigrade. 

        How could one not be enchanted by this beautiful aquatic creature, first described in the early 1800's, that looks like a gem and has ties to  hexagonal packing ?

       It's the perfect ambassador to ring in 2016! Happy Hexagonal New Year!


       

Looking forward to the power of 6 in the coming year; how about you?!
Steph


2016 blowing in via a Bernoulli Blower!

From Bdellium to Bdelloid Rotifers: Scrabble and Science Merge

           The search for Scrabble words starting with 'bd' brought me to both bdellium and bdelloid rotors (and, ultimately, back to our tardigrade friends).          

          Bdellium is a semi-transparent oleo-gum resin extracted from Commiphora trees growing in Ethiopia, Erythrea and sub-Saharan Africa. It is also an ingredient in myrrh.

        

            Bdelloid rotifers or "bdelloids" are asexual minute invertebrates found in freshwater habitats worldwide. There are over 450 described species. 

      

           Bdelloids share the ability to survive in dry, harsh environments by entering a state of desiccation-induced dormancy (anhydrobiosis) at any life stage (similar to the topic of an earlier post, the tardigrades ). This photo of one bdelloid species brought me right back to those Michelin Man tardigrades. 

       Like tardigrades, bdelloid rotifers are microscopic organisms, typically between 150 and 700 µm in length. They are slightly too small to be seen with the naked eye.

        Bdelloids reproduce by ingesting the DNA of other organisms like bacteria, fungi, and algae as described here.

       Bedelloid is from the ancient Greek βδέλλα , bdélla, meaning “leech."

       It's my first experience with words starting with 'bd." How about you? Have you seen bdellium in the ingredients list for your myrrh or run into any of the 450 species of bdelloids?

Happy 'bday' bdelloids and bdellium,

Steph

Tardigrades: Nothing to do with Being Late

     Tardigrades have nothing to do with being late to school, though biology students often study these tiny invertebrates with a low-powered microscope. Tardigrades are also known as water bears or moss piglets:

      The critters, which average .5 mm long, were discovered in 1773 and are nick-named for their resemblance to bears, though their taxonomic name, Tardigrada, translates to "slow stepper." 

     Tardigrades thrive in moss, lichen, lakeshores, and other moist environments though they are also found in extreme environments like deserts, deep ocean trenches, and in high tree tops. Water bears have a full alimentary canal and digestive system. Mouth parts and a sucking pharynx (see Scanning Electron Microscope (SEM) image below) 

  

lead to an esophagus, stomach, intestine and anus. They have well-developed muscles and a single gonad. Tardigrades have a dorsal brain atop a paired ventral nervous system.

     Tardigrades can withstand temperatures from just above absolute zero to nearly 100 degrees F above the boiling point of water, pressures about 6 times greater than those found in deep ocean trenches, being plunged in rubbing alcohol, ionizing radiation at doses hundreds of times higher than the lethal dose for humans, and the vacuum of outer space:

     Water bears can go without food or water for more than ten years, drying out to the point where they are 3% or less water in a process known as cryptobiosis. It astounds me to think of something with a brain and nervous system being able to curl up into a ball for years, lose most of their water content, and still survive. They can then rehydrate and just carry on normal lives. 

     Water bears have been around since the Cambrian period, surviving major extinctions at the end of the Paleozoic and Mesozoic time periods. There are over 1000 species of tardigrades, most with 8 claws or disks:

     Bob Goldstein from the U of North Carolina, who has done SEMinal (pun intended) research on the little beasts, says of water bears, “There’s one thing that we know of, which is some animals that survive drying make a sugar called trehalose.” He continued, “And trehalose sort of replaces water as they dry down, so it will make glassy surfaces where normally water would be sitting. That probably helps prevent a lot of the damage that normally occurs when you dry something down or when you rehydrate it.” Not all of the >1,000 species of water bears produce this sugar though, he says, so there must be some other mechanism involved.

     This 3-minute clip on Water Bear Research shows the moss piglets in a state of cryptobiosis, in some of their environments, as well as disabled students climbing trees from and in wheelchairs to discover new species of tardigrades. 

    Neal DeGrasse Tyson featured tardigrades this spring on Cosmos. Are they old friends of yours or new acquaintances?

Better late to the tardi(grade) than never, 

Steph

(Word Woman)

Guess what is in these two false-colored SEM images:

                     

                SEM IMAGE 1

                 SEM IMAGE 2

And for comparison, the same thing without magnification:

Aren't fractal veggies cool?

And one more in black and white:

                        SEM IMAGE 3

Those mathematicians can be vicious: