any clues what this is, please?

[fishwish]

friend found this on the beach here in Australia. It smells fishy - literally. it's light and seems hollow.
any clues?

[OdinsRaven]

My first thought is an egg or something related to it. Cool find.

[JackBean]

My first thought was a teeth

[wbla3335]

My guess is an air bladder.

[fishwish]

hi, thanks for those thoughts - I think a tooth can be ruled out, though it sure looks like one, because it's light and hollow and just not tooth material. An air bladder - had to look this up on Wiki, but I'd imagine it would have soft flexible walls? this thing hasn't collapsed out of the water, so it has some structure to it.
My original thought was also an egg, but of what?? weird shape, but then so are some critters.
Any further thoughts/info welcome

[wbla3335]

Have a look at this: http://www.julianrocks.net/Shells2/ShlPgs/PorcSb.html

[fishwish]

oh wow, that's it!! thanks so much - I'll let my friend know right now!
cheers!

[JackBean]

I agree it's the air bladder, that was my thought as well, although it is oddly shaped. But the "material" seems similar.