Marshall Research Interests
Some of reef fish are able to change their colours rapidly depending on the situation they are in. In addition to the amazing colours we as humans see, many fish can also see and use ultraviolet (UV) as a colour to communicate in their environment. As a research group we are particularly interested in addressing fundamental questions relating to what fish see and how this impacts their general ecology through both intra- and inter- species communication, feeding, camouflage and predation.
Adding to our interest in crustacean vision (see stomatopods but not forgetting fiddler crabs), and again using a system-wide approach incorporating physiology, ecology, anatomy, behaviour, neural integration and advanced imagining, we hope to determine what cephalopods (octopus, squid, cuttlefish) see and in particular how their brain processes this information. The first preparation used to discover how nerves function was a squid and the last detailed work on cephalopod neuroanatomy is over 50 years old. We are returning to this model system to learn more. Our aim is to understand how cephalopods see their world and communicate. How do they use their remarkable and famous camouflage while being colour blind? Have they ‘replaced’ colour vision with polarisation?
Stomatopods (mantis shrimps) are colourful marine crustaceans that live in reef environments as well as other less tropical and more muddy-bottom habitats. Stomatopod eyes contain up to 20 different functional input channels. These include 12 colour receptors (humans have only 3), 6 for linear polarisation (including a specialised UV polarisation channel) and 2 for circular polarization. Through an integrative whole-systems approach based on anatomy, physiology, ecology, behaviour, neural integration and advanced imagining, we hope to understand how and what these animals see, and how these animals process this complex information. This knowledge will help us determine how stomatopods use both colour and polarization to communicate and make decisions within their environment. We are already using this information in the bio-inspired design of optics and camera sensors.
Our key aims are to discover, observe and document new life forms from the deep sea and their associated sensory systems. As part of the Deep Australia ARC Linkage project, and in collaboration with industry partners Australian Oceanographics, Deep OceanQuest, Harbour Branch and Blue Turtle Engineering, we have developed an array of custom-made, state-of-the-art marine technology that enables us to sample organisms, measure environmental parameters and capture in situ footage of deep sea organisms like never before, for example Giant Squid. Please see our “research tools” for more information about our custom made deep-sea equipment, including camera platforms, trawl nets and submersibles.
Birds, Reptiles, Other Animals
The interests of the Marshall group often lead our researchers away from the lab’s model marine animals and into other exciting research areas where key concepts are applied to a diverse range of questions, applications and animals. For example, researchers from the group have looked at colour communication and retinal neurophysiology in birds, how jellyfish see, how spiders find the right rock to hide under and the evolutionary impact of body colour in lizards.
CoralWatch is a non-profit citizen-science organisation based out of the Marshall Lab. It is a community data gathering and environmental awareness project now in use in more than 80 countries and translated into 12 languages. CoralWatch integrates global monitoring of coral bleaching and reef health with education about coral reef conservation.