The environmental physiology and ecology of land crabs

Dr Lucy Turner (with Professor John Spicer and Dr Mairi Knight) works on the environmental physiology and ecology of land crabs, especially those endemic to Christmas Island in the Indian Ocean.

Her work seeks to understand the relevance of hormones as drivers of the seasonally variable ecology of these crabs, especially during their yearly breeding migration. Despite spending most of their life in the rainforest these crabs must return once a year to the ocean to reproduce, and consequently must embark on an arduous journey from their terrestrial home to the lower shore terraces where they undertake their breeding activities.

These crabs face extreme challenges from their environment, for instance it is the arrival of the monsoon rains which is the trigger for the migration to start, and thus the crabs must be able to cope with the twin demands of maintaining metabolic and ionic homeostasis during their journey. Recent findings (in collaboration with Prof Simon Webster at Bangor University) have revealed that hormone levels appear to be influenced by the existence of a seasonally dependent glucose-sensitive negative feedback loop which appears to be important in the control of energy supply during the migration.

Land crabs are also great models to enable us to understand more about the mechanisms that have driven the evolution of life from the marine to the terrestrial environment. Understanding the potential role of peptide hormones in this is another long term aim of her research.

Her research combines laboratory and field work (including regular trips to Christmas Island) in an integrated molecular, ecophysiological and ecological approach. Molecular ecology work has sought to understand the phylogeography of several of the island’s endemic land crab species and she is interested in applying the results of her work to the building of a long term strategy for conservation of the island ecosystem, including the challenges posed by global climate change.