Waitomo and its bright inhabitants

Although we went to Waitomo with caving in mind, we had to appreciate the scenery and the forces which drove the formation of these caves. Waitomo is a rural area, the sky was blue the grass was lush and green and the dairy farmers must have been happy, except for the occasional disappearance of the odd member of their flock. The bedrock is marble and the slightly acidic rain had worked it into some surreal formations, but it also carved huge cow-eating sink holes. The water that ran through these had formed the caverns we had explored yesterday.

A peaceful view of New Zealand Agriculture

The water wasn't only moving below the surface, which allowed our new hobby of photographing waterfalls.

The mighty Marokopa Falls

One of the sights that draws tourists towards the caves are the glow worms. Now, we don't really know who is reading this blog - but we suspect that the audience might be over represented by biologists. This one is for you. The glow worms in Waitomo are Arachnocampa luminosa. They are not worms at all, but resemble them during their larval stage before they pupate to an adult fly. The larvae make a structure resembling a hammock out of silk thread on the roof of a cave and then suspend a series of free hanging lines to catch prey. They glow in order to attract prey. Now, among the biologists reading this blog there may be a sizeable subsection of molecular biologists, skip this section. The glow worms glow because of a chemical reaction where the waste product luciferin is oxidised, a process that is catalysed by the protein luciferase. Discovering this made me terribly excited. Engineering the luciferase gene into plants is one thing that we can do to visualise where genes are expressed. I knew that the gene originally came from fireflies in Africa, it probably shouldn't have been such a surprise to hear about a similar reaction in the bums of New Zealand glow worms.

A pair of glow worms in a small cave.

Many glow worms hanging in the forest. Each glow worm seems to fluoresce with a different intensity; the hungrier the glow worm the more light it emits. 5 second exposure.