Today I left for the Ryukyu islands to attend an insect genome conference and collect specimens. Most people are familiar with Okinawa, which is actually the main island of what was once the Ryukyu Kingdom, independent of Japan. Excluding hundreds of years of history, The Ryukyu Islands and Okinawa are known today for their (sadly) dying language, interesting music, lion-dog statues everywhere, and unique food. Let’s not forget the tragedy of the Battle of Okinawa during World War II.
I first landed on the main island of Okinawa, but soon flew to the site of the conference, Kume Island. We were greeted by a bus schedule with an Okinawa-dialect ”めんそ〜れ〜,” (men-so-rayyy) which seems to be a mix between “Welcome” and “Hello.”
The island itself seemed fairly small, so we were looking forward to traveling around the forests in the mountains for specimens.
Map of Kume Island.
After unloading our things at the hotel, we headed to the beach to search for bioluminescent worms that live in the sand. We didn’t have any luck, but the view was certainly nice. This is A-ra beach on Kume island, there’s a nice mountain to the left.
The sand on the beach was made from crushed coral. You can even see the coral reefs from the shore.
Large bits of coral on the beach.
There were big chunks of coral lying about. Hopefully these weren’t victims of coral bleaching.
Due to some rain, we weren’t able to sample until late at night, but we had quite a catch! We were searching for firefly larvae, and were very successful. One interesting specimen we found, but left alone, was this larva hanging upside down from a twig grasped onto a snail. Many firefly larvae eat snails, and some are very picky – they only eat one species of snail! Firefly larvae usually live very close to water, both for breeding purposes (some spend their larval stage in water), and for finding food. Maybe all fireflies are French – you know, the whole “escargot” thing.
Here’s a shot of the fluorescent banding on the same specimen. This photo was illuminated with UV light. Many bioluminescent creatures have chemical compounds in their bodies that glow brightly (usually green!) when they are exposed to UV light. This is the same phenomenon, fluorescence, that occurs when you shine a black light onto highlighters, white t-shirts, and your dad’s groovy pink floyd posters from the 70s.
We found another species. This guy was a fatty! His light was so bright that it shone through someone’s breastpocket, illuminating most of their shirt. What species could it be?! We’ll find out soon enough after we do some DNA barcoding experiments!
でっかい – HUGE
I took a short video of some of the firefly larvae scooting around in case you’ve never found one in the wild. You can’t see it now since the lights are on, but their rears glow fairly brightly at regular intervals. It’s not a flash sort of glow, it’s more like a wave of light, fading in and out. _.,-~=^””””^=~-,._<–This is a graph of their luminescence.
Even more exciting for me were the glowing fungi and mushrooms we found. There are many bioluminescent species of fungi, many of which produce mushrooms that emit a continuous, fairly strong glow. It was my first time seeing it, so I was quite surprised at how bright it actually was. People aren’t really sure why mushrooms evolved the ability to glow, but some people think that it attracts insects to distribute their spores, and others think that it’s just a good way to get rid of dangerous chemicals that build up in the mushrooms while they’re glowing.
It’s pretty tough to take pictures of things that glow, I had to expose these photos for about 3 minutes to get them to be this visible. This is a great excuse to buy new camera equipment.
So you might be wondering why we’re bothering to study these glowing organisms. Simply put, by learning more about how these organisms glow, we can use their genes and proteins to make new discoveries in science and medicine. So far bioluminescent proteins have been used to monitor tumor growth, to detect food-borne illnesses on an industrial scale, and used in countless experiments as a sensitive detector for chemicals and genes.