The Secret World of Squid and Cuttlefish

The Secret World of Squid and Cuttlefish

They squirt ink, change colour, and taste amazing – they’re officially the coolest creatures in the sea.

At Rockfish autumn means one thing: squid season. Well, two things technically: squid and cuttlefish season. It’s the time when the deck of the Rockfisher gets stained black with the sticky, fishy ink that these alien-like creatures use to bamboozle potential threats.

If cephalopods, which is the family name for all squid, cuttlefish, and octopus, didn’t exist Hollywood would have invented them. If you look at a cephalopod (pronounced SEF-ah-lo-pod) it’s shocking to learn that they’re from planet earth let alone growing in abundance just within skimming stones distance of any of our Rockfish restaurants.

Straight out of Doctor Who these tentacled extra-terrestrials pack a Tardis-full of biological gadgets and gizmos gained through years of evolutionary struggle. Night vision that would be the jealousy of the SAS, ink cannons, colour changing skin, and an IQ higher than your average pre-schooler.

But even once you have grappled with the idea that we do share a planet with these monsters of the deep it’s still hard to believe that they’re readily available in British waters. Which is fair enough. We actually don’t tend to know much about cephalopods. To many they’re strange mythological creatures, the Kraken in Pirates of the Caribbean, or the ‘monster’ in Jules Verne’s Twenty Thousand Leagues Under the Seas.

Even in gastronomy, you’d be forgiven for conjuring up images of exotic global cuisines, rather than imagining them on the table of any British household. When you think about squid, octopus, or cuttlefish you think of that sweet and sour squid of southeast Asia. Or super fresh Japanese squid sashimi. Pulpo a la Gallega from Spain. Or, steamy bowls of jet-black Italian spaghetti – where cuttlefish ink is prized for its delicate sweet-seaweed tang. You don’t think England. And you certainly don’t think Devon.

However, as our waters warm in the UK our squid and cuttle fishery especially, is becoming increasingly abundant. Over the season it’s not uncommon to see over 40 tonnes of cuttlefish sell in one day at our local Brixham market. Any local fisher worth their salt will tell you with glee about the fish they adoringly refer to as “black gold”.

But as you hold back the salivating thought of crispy-calamari, fresh lemon, and aioli, we have to ask should we actually be eating cephalopods? Is it sustainable?!


Legend French sea explorer Jacques Cousteau called them “the long-ago monarchs of the sea”. Before human beings, or even dinosaurs, the planets number one predator was the cephalopod. How did they do it? Easy. They invented swimming.

Cephalopods are a type of mollusc. Like a garden snail. Like a garden snail their bodies are made up of two parts: a foot and a mantle. Similar to the technical challenge in The Great British Bake Off where bakers use the same ingredients to produce different variations of the same pudding, molluscs have used these two defining characteristic features (mantle and foot) in a variety of differing ways. Your garden snail, for example, oozes along on its slimy foot, protecting itself with a coiled shell mantle. A mussel, hides its foot inside a hinged shell, using it to latch on to rocks on the seabed. Cephalopods, meanwhile, divide their foot into arms and tentacles and shed the shell completely repurposing it instead into a soft muscular jet engine.

Originally, squid, octopus and cuttlefish, were like snails. They leached along the seafloor amongst all the other molluscs. Then, one sunny morning, 500 million years ago, they did something very curious. They filled their hard shells with gas and floated up becoming the world’s first swimmers. Sure, they were slow at first, but they had no need for speed. They drifted over the ocean floor, perusing their bottom dwelling prey like they were choosing from an all you can eat buffet.

The problem was, the rest of marine life soon caught on and saw swimming as a pretty hot skill to have. Fish evolved and suddenly buffet days were over. Fish could not only swim faster, but they could grow much bigger and crunch through a measly shell with one snap of their newly evolved jaws. For the early cephalopods it was not so much sink or swim, but rather, swim faster or become just another fossilised failure in earth’s great history.

Which over thousands of millions of years is exactly what they did, experimenting with various different designs, from coiling their shell, to truncating it, growing it in knots and eventually internalising it, and dissolving it to create a propulsion organ capable of propelling them through the water at twice speed of Michael Phelps.


Squid, cuttlefish and octopus are so strange, so other-worldly that it’s tempting to call them aliens. Indeed, when an octopuses genetic code was sequenced for the first time in 2015 a leader of the research team joked that it was “the first sequenced genome of something like an alien”.

Disappointingly, their findings showed that the octopuses genetic code is basically the same as that of a snail. Undeniably relating it, and every other cephalopod, to all other life forms on earth. But just because they haven’t arrived here from the planet Krypton it doesn’t make them any less cool.

The skin of a cephalopod is the most complex camouflage system in nature. Capable of hypnotising their prey with psychedelic patterns. Or simply blending into their surroundings. If colour-shifting was a sport they’d run rings around any chameleon.

In each millimetre of cephalopod skin there are 200 tiny spots of colour controlled by nerves that link directly to the brain. Colour change in a chameleon takes a couple of minutes. Changes in the skin of a squid, cuttlefish or octopus have been clocked at speeds of up to four per second.

With wizard-like powers of invisibility, and enhanced night vision the hunting squid or cuttlefish will silently sneak upon their quarry, before grabbing it with their tentacles which shoot out at the same speed of an AK47 round exiting its chamber.

Once the target is suckered, it’s then dragged into the cephalopods lethal embrace, where the victims spinal-cord is duly severed from one bite of its samurai sword beak.

While they don’t have a sonic screwdriver, squid and cuttlefish do have three brains. One behind each of their large dinner-plate eyes and a third which is shaped like a doughnut through the middle of which the creature’s oesophagus passes. As a result, eating is a little bit of a hazard. We all know what a nuisance it is to get a fish bone stuck in your throat, but for a squid or cuttlefish such a nuisance could be fatal. A stray bone can easily impale the creatures throat-brain killing it instantly. Much like your grandmother telling you to eat slower, the cephalopod eats in very small methodical bites. That or it simply eats its mate, or brother, or sister or cousin, being shell-less, and having no spiky little fish bones to worry about, cephalopods enjoy nothing more than eating other cephalopods. So much so, in one particular deep-sea species of squid cannibalism accounts for over 42% of their diet.


If you’ve ever sat down to a plate of our Salt & Pepper Brixham ‘Calamari’ (crisp fried cuttlefish sprinkled with black, white & Sichuan pepper served with Singapore chilli sauce) you’ll know that cuttlefish, as well as squid, are born delicious. Pretty much every animal that encounters one wants to eat them.

As a result, squid and cuttlefish are the sea’s Hells Angels. They live fast and die young. Within a year they’re having sex, and they’re dead within three. Producing hundreds and thousands of offspring. Their eggs are about the size of a Coco Pop, which makes them the perfect little snack for a hungry baby fish.

But those that survive this marine toddler predation turn the tables quick and within a matter of days they’re soon getting fat on the very babies that tried to eat them.

In the cruel cycle of life however, this rapid size increase gains them the attention of much larger species, like seals, sea birds and even sharks.

Being unshelled animals, cephalopods make great eating for any large carnivorous fish. While a jelly fish for example, might also not have a shell, it’s also 95% water and therefore not nearly as nourishing as these aggressive spears of juicy rich muscle. The sheer scale of cephalopod consumption in the sea is mind-boggling. A single sperm whale can eat 700 to 800 squid every single day.

Rough luck for the squid. However, it earns them the somewhat unconvincing honour of being “ecological keystones”. They start small, grow fast, and provide abundant food for marine predators of every size, even humans.


Cephalopods have been caught and eaten by humans for probably as long as humans have lived by the sea. However, recent research titled Squids in the Spotlight uncovered the enormous scale of the cephalopod fishing industry. It reveals that the world’s squid fishery has grown over 10-fold since 1950. Because squid are such an essential keystone species, this meteoric rise in their consumption is potentially jeopardising marine ecosystems globally.

The majority of squid sold in the UK comes from Pacific coasts of North America and the Asiatic seas. It’s fished by commercial boats that use banks of fluorescent deck lights to attract squid to hundreds of automated hooked lines. Each big ship working out of the Far East is capable of landing up to 50 tonnes of squid in one night (more than the entire Brixham fleet!), processing and freezing them all on board.

Is this sustainable? Absolutely not. Does that mean all cephalopods are unsustainable to eat? Of course not. We’ve just managed to get ourselves into a fishy mess. Almost all British cuttlefish (and a lot of our squid) is exported directly to Spain. In this country you’re more likely to meet a cuttlefish in a pet shop than on the fishmonger’s slab (the cuttle ‘bone’ is used to as a dietary supplement for budgies).

In return we import thousands of tonnes of frozen squid every year from southeast Asia. This makes zero sense. In taste a cuttlefish is almost identical to a squid, perhaps just being a little sweeter and little thicker. Yet for some reason we won’t touch it.

At Rockfish cuttlefish is on our menu year-round (except during its spring spawning season), we also preserve it in tins where the cuttle is seasoned in its own ink. It’s our take on a traditional Spanish snack, we urge you to give it a try.

Should we be eating cephalopods? YES! They are a fantastic fish that grow in abundance right off of our shores. But always British. It’s the only way to ensure that these “monarchs of the sea” are caught using low intensity methods, and haven't travelled thousands of miles to end up on your plate. Eating a squid or cuttlefish, fresh, fried and doused in lemon is the result of millions of years of evolution and biological transformation, and is nothing short of a total honour. Treat it as such and it’ll be an experience you’ll never forget.