Never Underestimate The Power Of Molluscs

Article | Updated 3 months ago

Ranging from snails to clams to octopus, Molluscs are the second largest group of marine invertebrates (animals without a backbone). Dr Lisa Kirkendale, Curator of Molluscs in the Western Australian Museum describes these invertebrates as 4 groups:

The Tasties: yummy things like clams and mussels
The Smarties: squids and octopus (have successfully predicted the outcome of the multiple World Cups)
The Pretties: sea snails, sea slugs, sea butterflies
The Poor Cousins: often forgotten, tiny, deep sea molluscs with shells

Being a large diverse group, there is so much to learn and discover about molluscs. They’ve been around a really long time, with fossil records dating back 550 million years ago. This also means that they can be used as a system to answer many interesting ecological and evolutionary questions.

Of particular interest are The Poor Cousins, which are found in the deep, dark corners of the ocean, in areas we don’t typically get access to. Much of those areas are still present all-around Western Australia and many other remote parts of the world.

The Microscopic Search

The Poor Cousins are small, microscopic molluscs. Because they are so tiny, how do we find and study these organisms, you may ask? The methods are interesting. A variety of methods are used, as opposed to using only traditional SCUBA surveys, we scrub rocks (like underwater Cinderella) and brush the underside of caves or areas where fauna inhabit. Sediments are collected, sifted through, and sorted under a microscope, before being individually picked out.

A person standing next to a body of water

Dr. Lisa Kirkendale out in the field
Image copyright WA Museum 

Sitting (on a microscope) and sorting through micro-mollusc is zen, it’s very relaxing and therapeutic, yet with the anticipation of discovering something new.

A picture containing animal, invertebrate, micro molluscs

Micro-molluscs from Epitoniidae, Epitoniidae, Dialidae, Rissoidae and Clathurellidae family (left to right), scaled to 1mm
Image copyright P. Middelfart, 2016 


Visible only under the microscope, these shells have beautifully intricate designs which are so captivating. 

UH Oh, They’re In Trouble

Micro-molluscs are very vulnerable to changes in our oceans. As our oceans become more acidic due to excess carbon dioxide getting absorbed into the seawater, the thin, delicate shells of micro-molluscs start dissolving.

How is this happening? Basically the acid strips these fragile beings of their calcium carbonate shells, altering its chemical properties. This affects their ability to build and maintain shells, especially during its early life stages.

Key points:

  • Molluscs are everywhere.
  • Sorting and finding micro-molluscs requires a meticulous eye. 
  • Increasingly acidic oceans cause the shells of tiny, vulnerable molluscs to be stripped off their shells.
  • There’s still so much to learn about our oceans, especially about the things we can’t see with our naked eye.

You Can’t Protect What You Don’t Know

There’s still so much to learn about our oceans and what lives in it. Molluscs are a diverse group ranging from the microscopic micro-mollusc shells to macro-molluscs like octopus. With groups like the micro-molluscs, its beauty often gets underestimated because of how small they are. Taking steps to discovering the beauty and importance these species have in our ecosystems are important before we are able to work towards protecting it.  

The new WA Museum, set to open late 2020, features a gallery called “Changes”- with a series of exhibits highlighting human impact on land and in sea through time in Western Australia. Amongst some of the topics presented include plastics, climate change and sustainable fisheries in WA. So, be sure to watch that space.

Articles
Siti Mutaza – Science Communication Practicum
University of Western Australia Student