Thesis: Neural correlates of predator avoidance in the fiddler crab
Historically, arthropod behaviour has been considered as a collection of automaton-like sequences commanded by domain-specific brain modules working independently. It is becoming increasingly evident that despite their comparatively simple brains arthropods are able to perform complex behaviours that are adaptable. Some semi-terrestrial crabs, for example, have evolved a multi-stage predator avoidance strategy, that allows them to efficiently avoid potential threats. At each stage of their response they make a decision about whether the threat is great enough to continue their escape. Recently, a number of neurons in the crab, Neohelice granulata, have been closely correlated with escape behaviours. However, there is still uncertainty about the specific role of each type of neuron and how these neurons work together to produce an escape response. In this project I aim to further understand the roles that these neurons might play individually and how they might work together to produce the well described escape response of the fiddler crab, Uca dampieri. To do this, I will use novel physiological and anatomical techniques that have the potential to improve the way that we study decision-making in animals. Additionally, I will develop a new method that will enable the estimation of specific visual capabilities from anatomy in preserved specimens. Information on the optics and morphology of visual systems of animals has been invaluable for making reasonable inferences about how animals perceive the world and for understanding adaptive aspects of their behaviour, including predator avoidance.
Why my research is important
A crucial problem for biology is to understand how animals, including humans, can make adaptive decisions in natural, complex sensory environments. The escape behaviours of crabs provide a unique opportunity to examine, in unparalleled detail, a decision making process that bridges the gap between simple reflexes and higher cognitive function. My project will further our knowledge of how simple nervous systems can make complex decisions, an important first step to understanding how more complicated animals make decisions.