Jan 27

#LoveSpecies nominee: common cuttlefish

Nominated by: Marine Conservation Society UK

Why do you love them?

The common cuttlefish (Sepia officinalis) is an incredible creature that we believe deserves more love. Amongst the most intelligent invertebrates known, cuttlefish will definitely appreciate the love we give them.

Cuttlefish have incredible eyesight and an odd W-shaped eyelid that allows them to have panoramic vision. Despite their eyesight being advanced, it is thought that they are colour-blind, which is even more amazing as their skill in visual camouflage is unprecedented. Even in the dark, cuttlefish can detect textures and colour from the environment to help them camouflage. It is not truly understood how they can do this, but the cuttlefish clearly has a unique perspective and relationship with the physical world that we are yet to understand. This mysterious creature also has three hearts so clearly has the potential to return our love in a triple heartfelt way!

What are the threats to the common cuttlefish?

Cuttlefish, like other cephalopods, are extremely sensitive to environmental variability and their populations can fluctuate rapidly. In order to know how many cuttlefish we can catch, we must understand how various climate and ocean variables are changing and how cuttlefish react to those important variables. The acidity of the water is particularly important to cuttlefish as it affects the density of their cuttlebone and therefore impacts their buoyancy. If we catch too many cuttlefish any year, there may be too few adults to spawn the following years. Cuttlefish are more frequently fished for and are often caught as bycatch.

Often there is little data available about the level of cuttlefish catches per year. Having so little data is a problem as we often don’t know how many cuttlefish that we remove from our seas, making it difficult to understand how many are left to spawn in the future.

What we do to protect them?

One of our collective aims at the Marine Conservation Society is to raise awareness of important marine habitats, to create a network of marine protected areas (MPA’s) in the UK and encourage the government to legally establish and protect a network of habitats. One of our established areas lie below the white cliffs of Dover and offers an attractive habitat for the common cuttlefish. The intertidal and subtidal chalk has formed unique reefs, ledges, gullies and sand pits where young cuttlefish can thrive as they develop their amazing camouflage skills. Our campaigns also aim to highlight the importance of collecting data on commercial fishing and bycatch, which may prove valuable for the government to further protect cuttlefish and other species alike.

VOTE NOW!

Apr 25

Cephalopods are arguably the weirdest of all marine invertebrates. The name cephalopod literally translates to ‘head-footed’ in Greek, indicating just how strange members of this taxonomic class are, but nothing in their name indicates how incredibly intelligent they are. Their alien-like features are truly fascinating and cephalopods are commonly regarded as the most advanced of all invertebrates!

The weirdest one – nautilus (Nautilus pompilius)

Kicking off our list is the bizarre-looking nautilus, whose appearance resembles a cross between a snail and a shrimp. They are the only species of cephalopod to have retained their external shell, which means they cannot alter their appearance as well as their counterparts.

The invisible one – common cuttlefish (Sepia officinalis)

The common cuttlefish is a master of disguise, possessing the ability to transform its appearance to suit its surroundings in an instant. Check out this amazing talent in this video!

The deadly one – southern blue-ringed octopus (Hapalochlaena maculosa)

This species has one of the most potent venoms on the planet, 1000 times more powerful than cyanide, and there is no known antidote. The blue rings after which this species is named will only appear when an individual is disturbed and serve as a warning before it attacks. The helpless crab in this video finds this out the hard way!

The strangely familiar one – opalescent squid (Loligo opalescens)

You may have come into contact with this cephalopod more than any other – the opalescent squid is more commonly known to us as ‘calamari’. These small squids live in extremely large shoals and hunt by striking their prey with their tentacles.

The one-size-fits-all one – curled octopus (Eledone cirrhosa)

The ability of the curled octopus to transform and camouflage its body is truly fascinating – there is no gap too small or seaweed too colourful for this species! The curled octopus is also equipped with an ink jet they can utilise as a distraction when a predator is nearby. On top of all that, it also has an extremely toxic venom that it uses to paralyse its prey!

The colourful one – Carribean reef squid (Sepioteuthis sepioidea)

Commonly found in shallow reef waters, this intriguing species has enormous eyes and is known to have the largest eye-to-body ratio of the whole animal kingdom! Carribean reef squid communicate with each other by changing the colour of their skin.

The huge one – giant Australian cuttlefish (Sepia apama)

The giant Australian cuttlefish is largest cuttlefish species, reaching lengths of up to a metre.  Despite its large size, this species it is a master of disguise and can easily blend in with its  surroundings due to special pigment cells called chromatophores which allow it to change colour in an instant.

The even huger one – Humboldt squid (Dosidicus gigas)

A close relative of the giant squid, this species, also known as the ‘jumbo squid’, is a monster capable of growing up to 2 metres long and weighing over 50 kilograms! They can move at considerable speeds (up to 24km/h) and have been known to propel themselves out of the water and soar through the air to evade their predators which include whales, sharks, seals and swordfish.

The bright one – firefly squid (Watasenia scintillans)

This bioluminescent species is definitely deserving of a top 10 spot as it is responsible for one of the most spectacular light shows on the planet! Between March and June millions of firefly squid gather off of the coast of Japan, as well as hundreds of tourists, producing a natural spectacle like no other. The firefly squid also uses its bioluminescence to attract prey and select mates.

The strong one – North Pacific giant octopus (Enteroctopus dofleini)

Reaching lengths of up to 5 metres and weighing in at up to 50 kilograms, this monster octopus had to make the top 10! The photograph below is not photoshopped, this species does eat sharks! Its raw strength makes it capable of ripping apart shells and flesh with its tentacles or using its powerful ‘beak’ to make easy work of its prey. This, in tandem with its camouflaging talent, makes it a truly ferocious predator.

Have we missed out your favourite cephalopod? Let us know!

Discover more cephalopods on the Arkive website

Will Powell, Arkive guest blogger

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