Presented by Jeremy Horowitz
James Cook University, Centre of Excellence for Coral Reef Studies; Museum of Tropical Queensland; and 2020/21 AMF/AMRI Visiting Collections Fellow, Marine Invertebrates, Australian Museum.
Dr Tim O’Hara’s dream is to create an ecological and historical biogeography of the global oceans for one entire class of animals: the Ophiuroidea (brittle-stars). For this, Tim has collated occurrence data from museum databases and literature from across the planet and embarked on a program to sequence 400+ genes from as many different species as possible to create a robust tree of life for the group.
To date, Tim and his team have sequenced almost 1400 samples for around 1000 species. Along depth gradients, ophiuroids form distinct faunal groups. The genetic divergence between shallow (0-200 m) and deep sea is profound and often ancient.
Latitudinally, ophiuroids are separated into broad bands (tropical, temperate and polar in both hemispheres) that reflect the cooling of the earth over the last 50 my. Longitudinally, the story is one of barriers and fluxes over time, as tectonic realignments open and close oceanic seaways. The fauna of the deep sea is well adapted to life in a challenging environment.