Banksy’s spokesperson wasn’t lying yesterday after telling Londoners to keep their eyes peeled for yet another animal mural. A seventh artwork has been confirmed on the artist’s Instagram, this time showing a school of fish – which look like piranhas – painted on a police box in the City of London, the capital’s financial district.

Conjecture has been rife on social media about the meaning behind the street artist’s recent series of animals plastered around London over the last week. They include a mountain goat, a pair of elephants, three monkeys, a wolf, two pelicans, a big cat, and now the fish.

The Guardian wrote yesterday, however, that Banksy’s support organization, Pest Control Office, said that “recent theorising about the deeper significance of each new image has been way too involved.” The paper said it “understands” that “the artist’s vision is simple: the latest street art has been designed to cheer up the public during a period when the new headlines have been bleak, and light has often been harder to spot than shade.”

PA Media reported that the fish mural, which makes the police box look like a fish tank, was picked up on CCTV cameras before being examined by police officers, who are awaiting orders about what to do with it. “We are aware of criminal damage to a City of London Police box in Ludgate Hill,” detective chief inspector Andy Spooner reportedly said. “We are liaising with the City of London Corporation who own the police box.”

So far, two of Banksy’s seven murals have been removed just hours after being spotted. A wolf painted on a white satellite dish in Peckham, south London, was stolen by a trio of hooded men in broad daylight on Thursday, while a big cat sprayed on a bare billboard in northeast London was removed by a contractor to prevent it being stolen.