If you talk to pet owners they will claim that their dog, cat, parrot or other animal companion has a personality of its own. It now appears that sharks too have distinct personality traits. Researchers at the University of Essex along with the Marine Biological Association of the UK (MBA) have shown that some sharks have strong social connections while others are solitary and try to remain out of the spotlight.

This should not come as a huge surprise. Although it is not clear how much personality is genetic and how much is shaped by environment and experiences, most researchers believe that both are part of shaping personality. Because no two animals of any species have the exact same DNA or share the exact same experiences, they would be expected to show different characteristics, even if the differences are slight.

In animals personalities are usually characterized by how bold, aggressive or exploratory an individual is.

For their research, published in the journal Behavioral Ecology and Sociobiology the team tested small spotted catsharks (Scyliorhinus canicula) in captivity in three different controlled environments. The sharks, commonly found in the Northeast Atlantic Ocean and Mediterranean, were placed in tanks which varied in structural complexity.

The sociability, or lack-there-of, of the animals is easily observable because of the way they group themselves. Spotted catsharks tend to group together, resting near to or even on tool of one another on the sea floor.

“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 colour with the colour of the gravel substrate in the bottom of the tank,” said Dr David Jacoby, a behavioural ecologist now at the Institute of Zoology, London in a statement.

“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 colour with the colour of the gravel substrate in the bottom of the tank. We define personality as a repeatable behaviour across time and contexts. What is interesting is that these behaviours differ consistently among individuals. This study shows, for the first time, that individual sharks possess social personalities.” said Professor Darren Croft, of the Centre for Research into Animal Behaviour in Psychology at the University of Exeter.

Although these specific tests were applied to only one species of shark, it is the first time such studies have been done on any species of sharks and adds to the perception that all animals will demonstrate individual personalities, to some extent.