Bioluminescence from the Sky to the Ocean Depths

It is nearly one month past the summer solstice and here in southern Wisconsin, the glow of fireflies at dusk and into darkness is a summertime pleasure not to be missed.

Fireflies employ the substrate luciferin and the enzyme luciferase, to produce their bioluminescence. The flash of a firefly lantern is designed to attract a mate, although with some species the potential mate becomes prey. Different species of fireflies have different flash patterns, which helps them find one of their own, when pairing off to create new little shiners.

A Photinus sp. firefly with glowing lantern. Image from art farmer, Indiana. http://commons.wikimedia.org/wiki/File:Photinus_pyralis_Firefly_glowing.jpg#mediaviewer/File:Photinus_pyralis_Firefly_glowing.jpg
A Photinus sp. firefly with glowing lantern. Image from art farmer, Indiana. http://commons.wikimedia.org/wiki/File:Photinus_pyralis_Firefly_glowing.jpg#mediaviewer/File:Photinus_pyralis_Firefly_glowing.jpg

In contrast to showy bioluminescence during night time flight, ocean depths have luminescence displays from a wide variety of creatures. Many of these bioluminescent sea creatures are recent discoveries, their discovery, habitat and behavior identified with the use of mini-submarines and non-manned submersibles.

One glowing example is the cluster wink snail. Terrestrial snails have been noted to leave a slightly luminescent trail of snail mucus as they crawl. But in 2010, the cluster wink snail was noted to flash a bright green light throughout  its entire shell. What better than an illuminated shell?

The snail has been noted to light up when disturbed, perhaps because the light makes the snail look larger. Or the bright flash may attract larger predators to come closer, scaring away the initial interrogator.

Continue reading “Bioluminescence from the Sky to the Ocean Depths”

Fireflies: Romance, Deception and Intrigue Coming to a Backyard Near You

Image of Photuris sp. firefly.
Photuris sp. firefly by day, deadly deceiver at night?

Here in the northern hemisphere, there are a variety of start dates for the beginning of summer. For parents of young children, summer may start the day after school ends. For others, Memorial Day and the associated long weekend is the start to summer. And of course there’s the vernal equinox, the longest day of the year, on or around June 21, for those that favor official timelines.

For yet others of us, summer begins with a trigger from nature: The first day above 90°F, or the day the tomatoes are planted, or when June bugs first appear on the back screendoor.

One of my favorite signs that summer is really here is the mid- to late-June appearance of fireflies. Few things are as magical as the displays of these flying bugs with their delicately flashing lanterns.

Fireflies could be said to mirror a good summertime movie. While they are appealing for their magical, romantic lighted displays, they are also chemical wonders that are capable of romantic trickery and deception. Continue reading “Fireflies: Romance, Deception and Intrigue Coming to a Backyard Near You”

Finding Science in a Campground

This past weekend, my family went camping with several other families. As the sun went down and the adults all gathered around a fire hoping smoke would discourage the mosquitoes, the kids ran about with glow sticks trying to catch fireflies.

Living in the Midwest, we all take fireflies for granted. One of my favorite things about summer is watching the fireflies (or lightening bugs as they are also called) rise out of the grass every evening. Even our kids just assume there will be fireflies in the summer. So it was fun to watch the reaction of our friend’s Grandma who, having lived her entire life in California, had never seen fireflies. As my son and his friend returned with glowing insects in hand, she was as excited as a child, and as I tried to explain to the kids how these little guys light up, she was the one who was fascinated. Continue reading “Finding Science in a Campground”