10 Underwater Creatures That Don’t Need to Dress up for Halloween

hw skeleton

Photo: Wikimedia Commons

There’s plenty of stuff underwater that – even if they’re perfectly harmless – most people wouldn’t want to meet, especially on a night-dive, when you’ve become separated from your buddy, and the battery in your flashlight is failing fast, and you start hearing the opening strains of The Twilight Zone underneath your hoodie. Remember: underwater, nobody can hear you scream.

Well, okay, if you shout loudly enough then yes, you can be quite easily heard underwater, actually. But it’s Hallowe’en, so here’s some underwater critters that might at the very least put you off your dinner, if they go bumping into you in the night…


hw amglerfish

Humpback blackdevil anglerfish, Melanocetus johnsonii. (Photo: Edith Widder / EOL)

The term ‘anglerfish’ covers a number of different species, all of whom have one thing in common: a bioluminescent lure that they can swing from the top of their heads to attract their prey, before sinking in a set of gnashers that would impress even Dracula. Definitely a case of having a face that ‘only a mother could love’, and well – it would have to be a mother, because mates are hard to find in the inky blackness of the deep sea, so females of some species form a very close bond with the males. So close, in fact, that the male’s head is fused into her body, effectively turning him into a portable sack of nuts. Who said romance was dead?


hw blobfish1000

Whoever gave the blobfish its name was perhaps a little bit lazy, possibly a little bit mean, but definitely scientifically accurate. Psychrolutes marcidus lives between 600-1200m near the sea floor where, to be fair, they look a lot less blobby than they do up here.They never visit the surface (with a face like that, who would?) – but they are sometimes accidentally brought up as bycatch and their gelatinous bodies – like lots of other fish – can’t cope with gravity. Voted ‘World’s Ugliest Animal’ in 2013.


The frilled shark (Chlamydoselachus anguineus) is one of the oldest surviving species of shark in the water – and therefore among the oldest animals to have ever inhabited the planet – with some estimates dating the species to around 150 million years. That’s twice as old as the last surviving dinosaur and 149.9 million years older than humans. The frilled shark is found from the poles to the equator in both the Atlantic and the Pacific, and isn’t thought to be dangerous. Pretty scary looking, but not dangerous…


hw isopod

One of the largest isopods, Bathynomus giganteus (Photo: Eric Kilby / Wikimedia Commons)

Looking for all the world like a giant woodlouse, but nastier, giant isopods are a group of crustaceans comprised of at least 20 individual species. Evil in appearance if not by nature, they thrive in cold, deep water, and range in size from 5cm and upwards. The largest model Bathynomus giganteus (pictured above) can reach up to 76cm in length and weighs in at close to 2kg. Just out of interest, woodlice are, in fact, crustaceans, not insects, and therefore B. giganticus is a distant relative, as are shrimp, crabs and other underwater shelled creatures. Now that you’ve seen it, an image of the giant isopod and his little pal the woodlouse will pop into your head every time you order prawns, or crack into a lobster. Forever.


The Goblin shark was discovered near Yokohama, Japan, and takes its common name from the Japanese word tenguzame, a creature of Japanese mythology similar to the goblins of western mythology and – well – because it looks like a goblin. Mitsukurina owstoni is, like the frilled shark,  one of the oldest living species of fish in the water, coming in at around 125 million years old. The elongated ‘nose’ gives it a fairly evil appearance, and at 3m long, it’s probably best not to encounter one while night diving, although as a deep-water shark that’s fairly unlikely. The jaws extend considerably when it feeds, adding to the nightmarish look.


hw thing

Eunice aphroditois, the Bobbit worm (Photo by Jenny / Wikimedia creative commons)

‘The Thing’ is an unknown species of polychaete worm that is occasionally sighted in the Caribbean islands of Curaçao, Bonaire and St Lucia, and is listed in fish ID books simply as ‘The Thing’. It is probably a relative of the creature pictured above which is the Australian version and known as the Bobbit worm. They say a picture tells a thousand words but what this one doesn’t tell is the story of the thousand legs. These giant worms look for all the world like giant centipedes but reaching over 2m in length and with infinitely more appendages. They are so rare that there aren’t many pictures on the internet, but you can find some close-up shots of The Thing in St Lucia in this article. Interestingly, the Bobbit worm’s scientific name is Eunice aphroditois. given that Aphrodite is the goddess of love, it seems likely that whoever named it was taking the mickey, or had been in the pub waaaaay too long.



Deep-sea dragonfish (Photo: JesseKlaggett / Flickr)

If somebody was to ever re-boot a very popular TV show and call it The Swimming Dead, then this would be the face of every flesh-eating zombie wiped out by – or indeed wiping out – the heroes. Dragonfish are agressive deep-sea predators, and Sloane’s viperfish (Chauliodus sloani) is the current world-record holder for tooth-to-body size of any living fish known to science, so large that the fish is unable to properly close its mouth. It hunts by opening its jaws and rushing at its prey, impaling its dinner in much the same way as any decent horror movie hero impales the undead. Fortunately, it lives very deep in the ocean and only grows to around 30cm – but one bite is all it takes…


hw wolfeel2

Wolf Eels (Anarrhichthys ocellatus) are actually quite lovely (Photo: Wikimedia Commons / D.P. Hershman)

Wolves look graceful, powerful, beautiful and majestic. Wolf eels do not. Growing to around 2.5m in length, Anarrhichthys ocellatus is mostly harmless to humans, although like the more common moray eels, if you poke around in its den, you’re going to lose whatever you’re poking with. Resident of the cooler waters of the North Pacific, wolf eels often mate for life, take up residence in a small cave and take turns guarding their eggs as the other adult goes foraging for crustaceans and shellfish. Rather a family-oriented sort of fish, really, and not at all scary. Just comes up a little short in the department of fairer features. 


No round up of Hallowe’en-themed aquatic life would be complete without the vampire squid. Unlike other species that sound dangerous but have deceptively boring scientific names,Vampyroteuthis infernalis quite literally translates as ‘the vampire squid from hell’. The name might be a little undeserved, however, as it doesn’t have fangs, the spines on the underside of its tentacles are harmless and it doesn’t suck blood. Possibly whoever named it had been up a little late reading Bram Stoker novels with a tad too much absinthe.


hw plastic

Plastic is one of greatest threats to our oceans, not scary fish (Photo: Rich Carey / Shutterstock)

If there was one thing that human beings should fear most about our oceans today, it’s not toothy, bitey fish or ugly monsters, even though – seriously – after the isopod you’re never going to look at a prawn cocktail the same way again. No, if there’s one thing to be afraid of, it’s not the creatures that are living under the waves, it’s the monstrous creation that is killing them en masse. Plastic in our seas has become a nightmare of epic proportions, and the results of its presence would turn the stomachs of even the hardiest of bloodthirsty horror movie fanatics. Hallowe’en probably started out somewhere in our distant past as a ritual to appease the souls of the dead, drive out evil spirits and set the world to rights before winter set in. It would seem that’s as good a reason as any to start thinking more carefully about our use of plastic, and what we do with it afterwards. Enjoy the evening, don’t let the trick-or-treaters rob you blind (or egg your car), recycle the sweet wrappers and the costume packaging and then perhaps we can start to set the world to rights. Again.

Happy Hallowe’en! 


0 replies

Leave a Reply

Want to join the discussion?
Feel free to contribute!

Leave a Reply

Your email address will not be published. Required fields are marked *