Common Cuttlefish

Up next we have a marine mollusc. (and, to be super bias, one of my favourites).

A recent addition to the aquarium is the common cuttlefish (Sepia officinalis). Though the name tries to suggest it, these animals are not fish at all, but molluscs, they’re related to octopus, squids and nautiluses, and more related to a garden snail than a fish. Maybe it was named by the same person who named the starfish a starfish when that's not a fish either. Then again, there's no true definition of a fish or what an actual fish is, but that's way to clever for me to even try and touch on, so I won't.

When we first got these cuttles in they were only a few cm in length, we fattened them up in the back and waited till they were feeding fine and grown on to put them out. They’re currently around 6cm in length.

(I do apologise for my gross looking finger. My hands are gross due to working with salt water, and also my fingernails grow pretty quickly and I'm convinced that's the salt too.)

The common cuttlefish can grow up to 50cm though the majority grow to 20-30cm in length and eat smaller molluscs like snails and clams, as well as crabs, shrimps and small fish. They are eaten by sharks and larger fish. They're also known to eat each other. But fear not, these guys have grown up together and get plenty of food so they won't be eyeing each other up for dinner.

Cuttlefish are amazing animals; I like to think of them as little rippling aliens. They can change the colour (by controlling their chromatophores) and texture of their skin to help camouflage into their surroundings. If you happen to be in our aquarium go and take a look you and you will notice the different body patterns each cuttle has depending on where they are in the tank. If they’re by a darkened patch with stones and other bits going on, they will create a disrupted body pattern- displaying a variety of coloured tones to blend in, and if they’re in clear sand the cuttle will be all one colour and bumpy.

This is going to be a long one because I do love these cuttlefish. So brace yourself for some reading, or just stop reading altogether and look at the pictures. Here's another picture.

Watching a cuttlefish feed is one of the best things ever. As a massive fan of watching animals chomping away believe me when I say this is something special. Cuttles are attracted by movement, if they see a crab or shrimp tottering along they will be on it. They like to "lure" their prey. Imagine the scene, there's a shrimp about and the cuttles spotted him, he heads over that way. Now the cuttle is face to face with this shrimp and now the cuttles moving two arms from side to side. The shrimps confused and curious, what is this lure? is it food? The cuttlefish still wiggling about starts to shimmer, ripples of colour go across his body and the shrimp is just fascinated, and in that instant the shrimp lets his guard down and the cuttle strikes! There are two tenticles hidden behind the 8 arms that are visible, these are special as they're long and fast and used to grab and stick to food. The shrimps now caught and stuck on the cuttles tentacles, and the cuttle pulls the tasty shrimp into its mouth (located behind all those arms). And starts to nibble away at it with its beak. Yes. Beak. I didn't say teeth I said beak. What a way to go.

Not the information you were looking for? Try MarLIN.ac.uk