The excitement continues: post-Lord Howe Island expedition
Collecting specimens was only the beginning of the process; now the lab-based work has started. Two teams in particular, Marine Invertebrates and Malacology had a very productive trip to the island.
Five pallets loaded with collecting gear and drums of specimens have arrived back at the AM and now the hard work begins, sorting and identifying the preserved animals that were collected. Our teams were specifically targeting marine invertebrates to build on the AM’s research collection. While there have been a number of collecting trips to Lord Howe undertaken since our opening in 1827, the aim of this trip was to obtain specimens that are useful for molecular study. Most of the earlier collectors preserved specimens in formalin, and while this is the best preservative for later study of anatomical features for most invertebrates, this substance breaks up the animal’s DNA, which is an additional powerful tool to help determine whether it is a new or previously known species and how closely it is related to other species.
While some species can be identified quickly, others, particularly the smaller ones, may require many hours of careful microscope work or DNA sequencing, analyses of past published literature, and often the involvement of particular specialists to complete the identifications. We have been asked already what our major findings are, but at this stage, until the work is done, we won’t really know! What is known for sure is that every time marine collections are made, new species are discovered.
One particular focus of this trip was to collect tiny micromolluscs that are found in marine sediment and are sometimes not much bigger than a grain of sand. They simply can’t be seen with the naked eye. The sediment samples needed to be sorted with the aid of a microscope to find and photograph these molluscs.
There are always new things to discover. One of the island’s residents, Molly Ball (pictured) showed us a very special shell of an air-breathing mollusc called Melampus castaneus. Molly found this snail and with her vast shell knowledge realised it was not something she had seen before. She was right. Ian Hutton sent a picture to the Australian Museum for identification just prior to our trip. Snail ‘guru’, Ian Loch at the museum (and a regular island visitor) provided the identification. While this species is found elsewhere in the Pacific (and sometimes called the Coffee Bean Snail), it had never been recorded before from Lord Howe Island, so Molly has made this important contribution to science through her discovery.
Our goal following from this trip is to prepare a checklist of marine invertebrates from Lord Howe. This record will provide an important snapshot of what we know about the island fauna at this time in our history. Change, particularly climate change, is clearly already affecting the distributions of marine animals, but before we can understand what is really going on in marine environments, we need to have a good idea of what exists in particular locations in the first place. We hope our work will add to this understanding. Watch this space for further updates!
By Dr Mandy Reid, Collection Manager, Malacology, AMRI