An almost half-tonne mako shark which died in the Mapua estuary could help unravel the mystery of how the beasts breed.
Touch the Sea aquarium marine educator Richard de Hamel said he was teaching a class at the aquarium when a local alerted him to the 3.6m shark yesterday, which was floating listlessly in the tide.
It was strange behaviour for mako sharks, which were believed to be the world's fastest shark, reaching speeds of up to 80kmh, he said.
It had earlier been stuck on a sand bar and then stranded on the beach opposite Mapua, until a man pushed it out into the water again.
It got beached again so the man tied a rope around its tail and with the use of a motor boat, dragged it across to the Mapua side of the estuary, where it was still just alive.
Because it was drying out, it was tied in the water until it died. It was then towed out and weighed at 460kg.
Mr de Hamel said he had contacted New Zealand shark expert Clinton Duffy, who was excited about the shark, as it was a female and little was known about the reproductive process of makos.
Because it had scars on its back, indicating recent mating, and it was the breeding season, it was likely to be carrying a pup, Mr de Hamel said. It was being stored in an industrial freezer in Richmond but would likely be partially dissected here, with its reproductive system being sent to Mr Duffy in Auckland.
But first, because it was such a good specimen, a cast would likely to be made of it, Mr de Hamel said.
And while the find may have been a scientific coup, it came with a loss to science, albeit to one octopus's gain.
Mr de Hamel said two remora fish that attach to sharks were still attached to it and he put them alive into the Touch the Sea holding tank, unaware that an octopus had also been put in the tank.
When he returned later in the day, there was one happy octopus and just one remora, which would be sent to Te Papa.
- © Fairfax NZ News
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