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Sharks have a fearsome reputation as ruthless and aggressive hunters.

But some 'tigers of the sea' can also be solitary, and prefer to remain in the background, according to new research on shark personalities.

UK scientists claim they have shown that the notorious predators have personality traits that determines how they behave in groups.

A University of Exeter team tested for social personality by recording the interactions of groups of juvenile small spotted catsharks in captivity under three different habitat types

A University of Exeter team tested for social personality by recording the interactions of groups of juvenile small spotted catsharks in captivity under three different habitat types.

The species of shark are found throughout the northeast Atlantic and Mediterranean and usually form mixed-sexed social groups driven by individual familiarity.

Ten groups of sharks were monitored in large tanks containing three habitats which differed in their level of structural complexity.

'We found that even though the sizes of the groups forming changed, socially well-connected individuals remained well-connected under each new habitat,' said Dr David Jacoby, a behavioural ecologist now at the Zoological Society of London (ZSL), London.

Ten groups of sharks were monitored in large tanks containing three habitats which differed in their level of structural complexity. The team 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 that appeared to reflect different strategies for staying safe. '

The study found that well-connected sharks formed groups, while less social individuals tended to camouflage alone, matching their skin colour with the colour of the gravel at the bottom of the tank.

'In the wild these small juveniles can make easy prey items for larger fish, so different anti-predator strategies are likely to have evolved,' said Professor Darren Croft, of the Centre for Research into Animal Behaviour at Exeter. 

The research follows a similar study last year by a biologist from the Bahamas who also discovered while that some lemon sharks (pictured) can be aggressive, others can be 'mellow'

'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.'

The research follows a similar study last year by a biologist from the Bahamas who also discovered while that some sharks can be aggressive, others can be 'mellow'.

Biologist Jean Sebastien Finger added that it is impossible to generalise the behaviour of one individual to a species.

In a study of young lemon sharks, he found that some of the fish were novelty-seekers while others were less sociable and played it safe when exploring a new enclosure.

Scientists are interested in comparing research into animals' personalities across different species to see how the quality has evolved.

A mixture of personalities in a group could potentially have a huge bearing on the survival of certain species.