BI: v8

GUANINE:   In 1844, when Abe Lincoln was a 35-yr-old lawyer in Illinois,  a German scientist, Julius Unger, isolated guanine from the guano droppings of seabirds. He named guanine after bird droppings–guano.  This bird-dropping fertilizer molecule, guanine,  is what our DNA uses for one of its 4 base pairs. it’s the G in A, T,C and G. 

GUANINE:   Guanine is often made into complex crystals in living things by DNA-made proteins. 

Sturgeons and Japanese Koi fish use these guanine crystals in their skin iridocyte cells to give the fish their silvery appearance.

GUANINE:   Lobsters use guanine crystals  to see with.  It lines their 8-sided octogon-tube eye cells.  This crystal paint-like coating reflects the light down the tubes to the lobster’s retina.

GUANINE:   We use liquid guanine in shampoos for a pearly iridescent effect.  In cosmetics,  it gives the pearly effect for nail polish.  It’s even used in metallic paints! 

In living things it is used for reflective layers in the eyes of deep sea fish and reptiles like crocodiles.  It is also used as the dielectric mirror on the ceiling of the incredible light-making chamber of the firefly. 

BOBTAIL SQUID:   In the bobtail squid’s mantle (which is the top… his “head”) he has a little chamber.  In the little chamber there are bioluminescent fungi.   When the bobtail squid is young, he has a filter that gathers the bioluminescent creatures up. His DNA also has a little breakfast recipe for them…It makes exactly what they need to survive.

BOBTAIL SQUID:   The bobtail squid feeds his bioluminescent creatures.  It’s a little like how our eyes’ cornea and iris are being fed by cells that eject nutrients into the aqueous humor which is behind your lens. (For this question refer to Eye 3 Core Video if you need to. We added the words  “cornea and iris” which are true. Or just look carefully at an eye diagram.) 

BOBTAIL SQUID:   There aren’t too many fireflies flashing in areas where there is too much light or on nights where there is a full moon.  Fireflies have sensors that detect how much light is around them.  If there is too much light around fireflies, then messages are sent to the brain.  Their tiny little brain then saves the flashing displays for a better day and a better place.

BOBTAIL SQUID:   Many bioluminescent frogs use this technique (above) to help keep them hidden.

BOBTAIL SQUID:   The tiny 40” bobtail squid will use its light intensity detectors to read the light penetrating the water it’s swimming in at whatever depth or time of day or night it is. 

BOBTAIL SQUID:   The Bobtail squid’s brain will match the brightness of the light coming from above it with the amount of light it gives off. This makes it so they are invisible to predators swimming above them.