The deep-sea remains the least explored environment on earth although biological adaptations to this extreme habitat have led to exceptional discoveries. Due to limited access and resources, and to the difficulty in performing in-situ experiments, the behaviour of most deep-sea organisms remains a mystery. The study of sensory systems can be used to shed light on the behaviour of these animals. One way to do so in teleost fishes, is to analyse the structure and size of the different brain areas of a species to identify sensory specialisations. Myctophidae (lanternfish) is one of the most abundant families of deep-sea fish. Recently, their visual system was investigated into details and results showed a huge interspecific variability in eye designs at all levels suggesting that some species might rely more on vision than others. The aim of this study will be to assess the diversity in brain morphology within the myctophid family to confirm whether some species rely more on vision than others and assess what other sensory systems lanternfish preferentially rely on. Relationships between brain area dimensions and the preferred environmental conditions of each species (i.e. depth, bioluminescence, sexual dimorphism) will be assessed, considering the evolutionary history of the family. Samples for this project have been collected over several deep-sea cruise. This study could include over 60 species of lanternfish, representing more than 50% of the recognised genera and provide a significant contribution to the understanding of deep-sea fish ecology and behaviour. This project will be done in collaboration with Dr Kara Yopak from the University of North Carolina Wilmington and Prof. Justin Marshall (QBI).

Supervisor:

Dr Fanny de Busserolles, (QBI) Email: f.debusserolles@uq.edu.au and Dr Karen Cheney