Tremoctopus: The Bizarre Blanket Octopus

On June 6, 2015 by Tim Newman

Blanket Octopus - Weird Facts

The tremoctopus, otherwise known as the blanket octopus, is one of nature’s oddest creations. It really does have some bizarre traits. And, when I say bizarre, I mean bizarre in a bold font for emphasis. It looks strange, as you can see from the image above, but when you find out what it actually does, well, you’ll probably cry elated tears of confused rage.

The blanket octopus comprises four species, all of which live in tropical and subtropical waters; they get their name from the curtains which liberally adorn their tentacles, making them look like a slimy bedspread. But it’s not just their duvet-like appearance that makes them strange.

Here are three incredible oddities about the blanket octopus:

1) Extreme Sexual Dimorphism

Blanket Octopus - Weird Facts 2

Many animals display sexual dimorphism i.e. the males are larger than the females, or the female is less colourful than the male etc. This sexual dimorphism reaches ludicrous extremes with the blanket octopus.

The female can reach 2 metres (6.6 ft) in length, but the male is only a few centimetres long. Now that’s extreme sexual dimorphism for you.

It’s the largest sexual difference in the animal kingdom, the female is often 40,000 times heavier than the male.


2) Reproduction The Weird Way

Blanket Octopus - Tremoctopus

Male blanket octopus store their sperm in a modified third right arm called a hectocotylus. This isn’t too odd, cephalopods (octopus, squid, cuttlefish etc.) often have sperm storage devices like these. But they’re pretty creepy. During mating, the arm detaches itself and crawls, all by itself, into the female’s mantle to fertilise the egg. Gross, huh?

The male has this one role to complete and dies shortly after mating. It wasn’t until 2003 that scientists first saw a male blanket octopus swimming in the wild. They aren’t much to look at.

3) Portuguese Man O’ War Immunity

Blanket Octopus - Tremoctopus video

The Portuguese man o’ war is a fearsome beast. It has enough fire power in its stinging tentacles to kill a man, and those tentacles can drift 10 metres from its balloon like head.

They look like jellyfish, but they are actually a siphonophore. Siphonophores are a huge society of tiny zooids that all club together to make what looks like one creature; they’re a colony rather than an individual. Weird.

Blanket Octopus - Portuguese Man O War

The Portuguese man o’ war is strange to start with, and it is rightly feared by many a sea creature, but not our blanket octopus, oh no. Do you know what the blanket octopus does? It seeks them out and rips off their dangerous tentacles. And what does it do with them? It wears them to defend itself from others. They are completely immune to the sting somehow.

So they are weird, gross and powerful. What a trinity.

Here’s a video of a blanket octopus for you:



To summarise: the blanket octopus looks weird and it most certainly is weird.





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