Do you know the origin of the term “Siamese Twins”? It comes from Chang and Eng Bunker, conjoined twins who travelled the world in the 1800’s lecturing and being gawked at. They came from Siam (modern day Thailand). Now their journey might sound logistically tricky but there are conjoined twins in the ocean that take it one step further.
Siphonophores are long stringy animals that were believed to grow (until recently) up to around 30m long. But they are not technically one animal. They are instead a collection of asexually reproduced clone bodies all joined together These clones, called zooids, all have specialised functions, such as floatation, movement, feeding, protection and reproduction. Joined, they behave as a single large animal.
You might think they seem bizarre and alien but there’s one Siphonophore I bet you’re all familiar with.
It’s the Portuguese Man-O-War, or Blue Bottle Jellyfish. The large blue balloon on top is a single zooid that maintains buoyancy and catches the wind allowing it to sail. The parts dangling underneath are strings of tiny zooids for stinging, digesting and movement (retracting tentacles).
You might also recognise another Siphonophore, this one.
This was spotted by an ROV on a deep sea dive here in Western Australia near Ningaloo. Remember how I said it was believed that Siphonophores got up to around 30m until recently. Well this one was spotted in early April and is estimate to be around 50m long!!! That’s a lot of conjoined twins.