Some sharks are more 'gregarious' than others and have strong social connections while others are solitary and prefer to remain inconspicuous. That's not an exception, according to a new study, these notorious predators have personality traits.
Personalities obviously exist in many animals but are more broad; how exploratory, bold or aggressive an individual animal is. The new work examined social personality by recording the social interactions of groups of juvenile small spotted catsharks (Scyliorhinus canicula) in captivity under three different habitat types.
The catsharks are found throughout the northeast Atlantic and Mediterranean and group together by, around and even on top of one another on the bottom of the seafloor. Ten such groups were monitored in large tanks containing three habitats which differed in their level of structural complexity.
Sharks have personalities but sometimes we think they do based on the angle of a photo. A shark upside down can be Halloween every day of the year.
Lead author Dr. David Jacoby, lead author from the Institute of Zoology, London said, "We found that even though the sizes of the groups forming changed, socially well-connected individuals remained well-connected under each new habitat. In other words, their social network positions were repeated through time and across different habitats.
"These results were driven by different social preferences (i.e social/antisocial individuals) that appeared to reflect different strategies for staying safe. Well-connected individuals formed conspicuous groups, while less social individuals tended to camouflage alone, matching their skin color with the color of the gravel substrate in the bottom of the tank."
Senior author and University of Exeter Professor Darren Croft added, "We define personality as a repeatable behavior across time and contexts. What is interesting is that these behaviors differ consistently among individuals. This study shows, for the first time, that individual sharks possess social personalities.
"In the wild these small juveniles can make easy prey items for larger fish, so different anti-predator strategies are likely to have evolved. More research, however, is required to truly test the influence of predators on social personality traits in sharks. This study is the first step in that direction."
