Various seaweeds grow flotation nodules like this in order to hold themselves upright.

And it's segmented like and tastes like an orange. That's just too cool for words!

Carole

@ tcstoehr

Have you got a link to this information? I can't find anything at all like this nor can I find anything to do with seaweed flotation nodules and as I said there was NO other signs of it on other seaweeds.

@ Carole

It is too cool I intend to keep it as long as possible theres a seed in it as well but I don't see how it could possibly grow...even if it grew into a miniature orange tree it would be pretty damn awesome.

and I mean come on...it's exactly like an orange it can't be anything but an orange surely?

Edit:

Originally I thought maybe this could of been caused by cross-pollenization but not being a plant/fruit expert I'm not really able to judge and I'm not even sure if it would be physically possible to cross pollinate an aquatic plant with a citrus fruit...but weirder things have happened.

maybe it's you saw an orange/citrus branch with a fruit still attached that blew off a tree and got blown into the ocean, then the branch side sank and the orange floated.

oh and no, no cross-pollination/hybdridization is possible - seaweeds and land plants like citrus are far too unrelated to cross. A lot of seaweeds aren't even plants in the scientific sense, they're collections of algae.

Note though that a lot of plants that aren't even in the citrus family produce citrus scents, and segmentation in fruit isn't uncommon

I mean cross-pollination/hybridization is not possible

Jaytac:

A marine biologist familiar with the sea plants of Australia would be the best source of info for you. I don't know whether you are currently in Australia or the UK, but Australia has outstanding professionals in this field. Here, we are mostly backyard fruit growers, though many of us have other interests as well.

I can't think of an event more wierd than cross-pollination between a seaweed and citrus fruit, and if anything wierder has happened, I haven't noticed it.

Don Yellman, Great Falls, VA

The actual term for the "flotation device" that seaweeds use is pneumatocyst. Google for "seaweed pneumatocyst" and you'll find what I'm talking about. Keep in mind that different sea plants will have completely different forms of pneumatocysts. A segmented pneumatocyst is quite logical as the segmentation would give structural support.

@ tcstoehr

searching seaweed pneumatocyst came up with 453 results and although would seem to be the only logical explanation I really doubt this is one of them, pneumatocysts contain carbon dioxide, surprisingly to help them float lol the concept of a pneumatocyst that's fruit like wouldn't really be efficient as a flotation device I doubt.

@ peanuttree

Even so I've not seen a fruit like this and It wasn't in the water, it was on the beach attached to the seaweed, I know for sure because I picked it up by the "fruit" I'm also sure it was seaweed not a branch.

@ jellyman

I'm in Australia till the 27th I think but, although a marine biologist would be useful, this would baffle them either that or they wouldn't believe me seeing as I technically have no other proof then the fruit itself which, as time goes by, is getting dryer an dryer and will eventually rot, shamefully I didn't have the sense to take it with the seaweed or even attached which would of definitely helped me.

Thanks everyone for replying.

you haven't preserved it? Freeze it or dry it or something. Or go to a college/university to talk to a seaweed expert and ask them to preserve it in formaldehyde. The only thing you could lose is a little bit of your time, but if you're right and it is a new discovery you'd be the discoverer of a new specimen!

Is it possible somebody may have discarded a citrus fruit amongst some wet seaweed on the beach, and after drying it became stuck to it? It may then have appeared to have been growing directly from the clump of seaweed? Many seaweeds contain sticky proteins and indeed the Japanese cultivate the Funori seaweed to be processed and used as glue. Just a suggestion as it seems unlikely to me that this is a new citrus species that grows in the sea.