Shark's brains share several common features with those of humans, scientists at The University of Western Australia have found, prompting a suggestion it may help researchers working to design a shark repellent.
The parallels are outlined in several papers published in a special edition of the journal Brain, Behavior and Evolution.
The special issue - The Nervous System of Cartilaginous Fishes - focuses on the latest comparative and evolutionary research on the brains of sharks and other cartilaginous fishes, such as rays and sawfish.
"The studies cover several areas of recent research and suggest that people may have more in common with sharks than we thought," said the issue's editor, Dr Kara Yopak from UWA's Oceans Institute and the University's School of Animal Biology.
"Sharks, and their relatives, represent the earliest jawed vertebrates. Despite broad divergence, there are a number of common features of the brain that evolved at least as early as cartilaginous fishes, and persist across all vertebrates.
"For instance, one of the papers shows that with great white sharks, the area of the brain that receives visual input is quite large, and suggests the relative importance of vision in these animals is quite high.
"This information may direct researchers' efforts towards targeting the visual system when developing repellents for sharks."
Although sharks were previously thought to have relatively simple brains, the researchers have shown that sharks and other cartilaginous fishes have a battery of highly developed sensory systems and relatively large brains.
"Another of the papers suggests that the cerebellum - which appeared first in early sharks - is an important evolutionary advancement that has paved the way for some aspects of higher neural function in vertebrates, including humans," Dr Yopak said.
The papers in Brain, Behavior and Evolution that feature UWA Oceans Institute researchers are:
Preface, Dr Kara Yopak, UWA Oceans Institute and School of Animal Biology.
The Neuroecology of Cartilaginous Fishes: Sensory Strategies for Survival, Winthrop Professor Shaun Collin, UWA Oceans Institute and the School of Animal Biology.
Electroreception in Elasmobranchs: Sawfish as a Case Study, Barbara Wueringer, UWA Oceans Institute and the School of Animal Biology.
Allometric Scaling of the Optic Tectum in Cartilaginous Fishes, Dr Kara Yopak, UWA Oceans Institute; and T.J. Lisney, University of Alberta.
The Cerebellum and Cerebellum-Like Structures of Cartilaginous Fishes, J.C. Montgomery, University of Auckland; D. Bodznick, Wesleyan University; Dr Kara Yopak, UWA Oceans Institute and the School of Animal Biology.