Molluscan deep-sea diversity

We are tracing the evolution and diversification of deep-sea molluscs and investigating how they adapt to their environment.

The deep sea was once thought to be devoid of life. Studies over the past 100 years, however, have shown there is a great diversity of life well adapted to the conditions of the deep.

Molluscs have not only survived in the deep sea, but have diversified and spread widely.

The deep marine environment is at risk from overexploitation and habitat destruction as a result of fishing and mining ventures. It is important to learn about the diversity and evolution of organisms in the deep before there is further destruction.

We are using molecular methods to build robust phylogenies of deep-sea molluscs to help answer some fundamental questions.

Research questions

• How have eyes evolved in deep-sea gastropods?
• Have changes to diet enabled shallow water lineages to invade the nutrient-poor deep sea?
• Can complete mitochondrial genomes help resolve the phylogeny of deep-sea bivalves?
• Has Antarctica acted as a source of diversity for deep-water communities elsewhere?
• How has global climate change affected evolution on the continental slope?

Some deep-sea molluscs have developed novel diets. Some have become carnivorous while others survive by only eating wood.

Preliminary results

Our research so far has shown that Antarctic species samples represent a recent invasion. 

We also show that a global cooling around 33.7 million years ago created a great diversification among the deep-water solariellid gastropods. This appears to be a result of increased nutrients supplied to the ocean by changing erosion, ocean circulation, tectonic events and upwelling.

This suggests that food availability may have been a factor limiting the exploitation of deep-sea habitats.