Lobster navigate using odours and water flow, and fisherman exploit this by baiting their traps to attract the lobsters. However, little is known about optimal bait types and the important odours found in plumes that attract lobster. Our goal is to build understanding of lobster responses to bait by:
- using laboratory experiments and underwater field video surveys to better understand lobster responses to natural food sources and bait
- analysis of larger scale lobster movement patterns relative to bait odour plumes generated by lobster traps
- analyzing chemical constituents of bait for their attractiveness to lobster
A primary driver behind this research to is help lobster fisherman attempting to improve the cost-effectiveness of their bait use.
Collaboration with Jim Williams and local lobster fishermen.
The sea slug Tritonia Below: video shows slugs navigating towards and feeding on soft coral prey.
Navigation is a key behaviour performed by all motile animals. We work with gastropods because they are both amenable to a variety of experiments (both behavioural and neurophysiological) and they provide an interesting contrast to the navigation behaviours of other animals. Slugs and snails primarily relay on odours and water flow to guide their longer distance movements, although light and other cues (including possibly the earth’s magnetic field) also can play a role. Our long term goal is to understand how the different sensory cues are integrated together to produce the coordinated responses we see as the animals seek out food and possible mates, while avoiding predators.
We tackle this problem using several approaches:
- Modelling of navigation based on different sensory systems (including chemosensation, mechanosensation, and magnetoreception) and to explore the relative performance of different strategies in different sensory cue regimes.
doi: 10.1093/icb/icv073 doi:10.3389/fnbeh.2010.00042
- Field observations and experiments using SCUBA and underwater video to characterize the sensory cues and navigational responses in sea slug Tritonia
- Tritonia and the pond snail Lymnaea
Laboratory experiments testing responses to different sensory cues (odour gradients, odours plumes in flow, etc.) in both
doi: 10.1242/jeb.02164 doi:10.1080/10236244.2015.1123870
- Neurophysiological experiments exploring the connection between the sensory organs that detect odours, flow and other cues, and the motor neurons that control turning.
A Tritonia neuron responsive to predator odour
Collaborators: Ryan Lukeman, Jim Murray
A control plate (left) fouled by C. intestinalis vs a siloxane plate (right) with reduced fouling.
Biofouling, or the growth of organisms on man-made surfaces, affects many industries: food production, oil and gas, and shipping, among many others. As part of the StFX Centre for Biofouling Research, we are exploring novel non-toxic options for reducing biofouling, particularly focused on cold water marine habitats. The WyethLab’s role is primarily involved in field surveys of biofouling and field tests of candidate coatings that may reduce biofouling. We also partner with industry members to collaborative test commercial coatings.
Our projects include:
The pond snail Lymnaea
Sensory systems are a key component in the control of most behaviours. At present, our understanding of gastropod sensory systems is limited. Previous research on the peripheral nervous system has created a patchwork of information encompassing different sensory cell types scattered across different species. Our long-term goal is to create a catalog of sensory cell types, including morphology, distributions and modality (particularly mechanosensory vs chemosensory).
Our experimental animals for this work:
Hermissenda‘s brain, with histamine in the statocyst (s) but not the eye (e).
- Lymnaea stagnalis (pond snail)
- Hermissenda crassicornis (opalescent nudibranch)
- Aplysia californica (California sea hare)
And we use these animals in various projects:
- Immunohistochemical, backfill, and vital dye labelling of sensory neurons to provide both anatomical information as well as putative neurotransmitter(s) for each sensory cell type.
- Behavioural assays to test the roles of different sensory cell types/neurotransmitters in different behaviours.
- Novel approaches to assessing function of the sensory cells by directly testing their responses to mechanical and chemical stimuli (optical recordings) or making use of modern molecular genetics (gene expression analyses, perhaps knock-down experiments).
Sensory cells in Aplysia siphon
Collaborators: Roger Croll, Dan Jackson, Scott Cummins
Project Update: we develop methods (hacks) to analyze videos using freely available open- source software.
A “videogram” showing movement path of a sea slug. Video below demos its creation.
The overall goal is two-fold:
- Create frame-processing algorithms that allow videos of animal behaviour to be displayed as single images displaying key components of behaviour. Subsequent image projection techniques then allow all replicates within a treatment to be combined into a single image. These then provide a useful tool for qualitative and quantitative analyses of behaviour without explicit of tracking of structures or individuals.
- Establish work-flows for using open-source tracking software options with maximum flexibility in video sources and subsequent analyses.
Examples of our videograms or tracking used to analyze behaviour in:
Some initial tips…
For videograms: This chapter explains videograms and how to use them in more detail. To get started, use the demo procedure in ImageJ to produce a videogram from one of the versions of this sample video.
For open-source tracking: start with ImageJ (that’s the FIJI version), and make use of the FFMPEG plugin (available in the “Manage update sites option” in the Updater). Then explore the MTrackJ (manual tracking, great analysis options) and Trackmate (automated tracking) plugins. This converter helps get Trackmate data into MTrackJ for analysis.