This is a 'Cask' or 'Tun' shell.
I found it and several broken ones on
Tokerau Beach where I have been parked for a few days.
They live at a depth of 25-145 metres
and eat sea cucumbers, starfish, sea urchins, crabs and
burrowing shellfish, finding their way in by drilling a hole.
There has been stormy seas and a variety of shells and
lots of seaweed washed up.
They are amazing shells. This one is 15cm long.
They don't grow much bigger than this.
As you can see it has a big opening where the fish has been.
Details in my shell book told me is has no operculum,
or stopper (we can know them as cat's eyes)
to protect the fish.
It has a small hole otherwise it's a perfect shell...
Quite rare as the shell is very thin and brittle so easily broken.
They are only found round the top half of New Zealand's
north island on both the east and west coasts.
They are also found round Australia where they are known
as the 'Beer-Barrel Tun'.
These are the others I found, all broken but beautiful colours
It's interesting to read about the home that this shell was
and the life of the shellfish...
Before I found them empty...
Floating in the low tide.