Perth boys bitten by animal not a shark

Whatever creature bit two 10-year-old boys on their legs at a Perth beach was not a shark, authorities have confirmed.

A shark warning at Perth metropolitan beaches has been downgraded after a Fisheries Departmenbt investigation found the boys' injuries were not consistent with a shark bite but "some other marine animal".

The pair suffered minor injuries after they were both bitten within the space of a few minutes on Wednesday while wading in knee-deep water about three metres offshore at Waterman's Bay Beach.

Fisheries officers sought expert scientific opinion on the bites using photographs supplied by one of the boys' family.