It takes a long time be­fore sharks sleep with the fishes

The Courier-Mail - - NEWS -

SHARKS and rays live a lot longer than thought, some twice as long as pre­vi­ously es­ti­mated, ac­cord­ing to a Queens­land study.dy.

Dr Alas­tairr Harry, of Jamess Cook Univer­sity,y, re­searched 53 3 dif­fer­ent popu- la­tions of sharks s and rays and dis­cov­ered that a grey nurse shark k can live up to 40 0 years – twice as s long as had been es­ti­mated.ti td

“And the age of New Zealand por­bea­gle sharks had been un­der­es­ti­mated by an aver­age of 22 years,” he said. “Across the cases I stud­ied, age was un­der­es­ti­mated by an aver­age of 18 years and up to 34 years in one in­stance.” Sci­en­tists usua ally mea­sure a sh shark’s age by count­ingc the rings in their ver­te­brae. Dr Harry said thatth er­rors in cal­cu­la­tionsc ap­pearedp to have oc­curredo due to growthg rings ceas­ingceasin to form or be­com­ing un­re­li­able be­yond a cer­tain size or age. Age cal­cu­la­tion is im­por­tant for the man­age­ment of ma­rine re­sources.

AC­TION: Jaiden John­stone and Tia Boyd-Long set­tle in; and (left) Bris­bane’s grand old Re­gent Theatre. Pic­ture: Peter Wal­lis

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