Cavernhouse – Travel-along.in

New Zealand is home to this natural wonder. The glowworms are widespread in New Zealand generally in cave systems. The most popular of the cave systems to view glowworms are at Waitomo, Te Anau and Waipu.

A short introduction on the glowworms

The New Zealand variety of glow worm is actually the larva of an insect which looks like a mosquito. The scientific name is Arachnocampa luminosa. The larva produces a blue green bioluminescence. The Maori name is “Titiwai “meaning projected over water. They live in dark, cool , damp and humid environments like caves, sheltered banks and native bushes.

This is not to be confused with fireflies which also are bioluminescent but belong to the beetle species.

The insect eggs are deposited on cave walls. On hatching, the larvae immediately begin to glow. They grow from the initial size around 4 mm upto 40 mm. over several months. They move around the cave wall and finally attach themselves to a site and start producing a silk nest. The larva produces long silk threads which have sticky droplets on them to capture prey.

The bioluminescence is a result of an enzyme luciferase acting on a molecule called luciferin. Though the enzyme has similarities with that found in fireflies and other bio luminescent systems, the composition of luciferin is totally different in this species. The purpose of this glow has been attributed to attracting prey and also potential mates.

The adult stage

The larva and the silk threads

Bioluminescence

Our Trip

We decided to do the glow worm tour at Te Anau. Real Jouneys is the tour company which organizes these tours from Te Anau.

The glow worm caves lie in the mountains across the Lake Te Anau .The caves are around 12000 years old and are still being carved out by the force of the water that flows through them. The result is a twisted network of limestone passages, whirlpools and an underground waterfall.

Tourists have to take a catamaran to the other side of the lake. These caves are situated close to the water level and the trips are called off if there is flooding in the caves. The trip was cancelled on the previous day due to heavy rain and flooding of the caves.

We were lucky to get a rain free day to do the trip. The catamaran ride lasted about 40 minutes.

Once we reached the other side, we were guided by helpers to get across the slippery rocks on the edge of the lake. The whole area has a very marshy , damp , slippery appearance with dense vegetation .Then we were guided to the Cavern House. The Cavern house has tourist facilities like a small cafe , toilets etc and has a small hall where the guides explained about the bioluminescence and the larvae . There are educational exhibits here too…

The mountains where the caves are situated

The catamaran luminosa that takes you across Lake Te Anau

The Cavern House

Photography is strictly prohibited in these caves.

After the educational session, we were divided into small groups with a guide for each group. We followed the guide along some narrow passages among caves. At many places, limestone formations are seen inside the caves. One has to bend and turn and manouvre oneself to prevent injuries from jutting rock formations. As we went further inside, it got darker. The guide had a headlight on her forehead. At places, there are steps made manually too. At places there are small lights too.

As we walked along the caves, there were silk threads visible at places. But the larvae could not be seen. Finally we reached a small area with flowing water and we boarded a very shallow boat. The boat is so shallow that you cannot sit upright. This is also to prevent injuries to the head as the boat goes through the narrow channels.

Once the boat was on its way, we started seeing the beautiful blue green light all along the walls of the caves. At places, it was very bright and at places it was dull. I assume it depends on the density of larvae at that site. It was indeed a great experience. It looks like a sky lit up with stars!!

Some pictures…