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MARINE Cephalopods

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A former senior biologist, and MASNA’s Aquarist of the Year for 2014, Richard is a committed ceph fan.

RICHARD ROSS

The trouble with CEPHALOPODS…

Who wouldn’t be excited about keeping an octopus? Alas, such a magnificent creature is a high demand

animal with a short life. Richard Ross discusses.

CEPHALOPODS ARE some of the coolest animals on the planet. Octopus, cuttlefish, squid, and curiously shelled nautilus intrigue us for good reason;

their big eyes, along with their many arms and tentacles, make them simultaneously attractive and repulsive to the human eye.

They move like they are from another planet. Their copper-based blood is blue. They are masters of camouflage, capable of changing the colour and even the very texture of their skin. They have jet propulsion, suckers, a parrot-like beak, three hearts, weird shaped brains, extensive nervous systems, magnificent eyesight, amazing behaviours, a toxic bite, and can disappear in a cloud of ink when they are threatened. What’s not to love?

As a result of all this, all too many people look into those large ceph eyes, and think “I’ve got to have one in my tank!”

But do cephs really make great pets? For the dedicated, experienced, and slightly insane saltwater aquarium keeper? Yes. For everyone else? Probably not. It is my hope that this article will encourage you to think hard and long about whether keeping these animals is right for you.

General considerationsIt is important to realize that all cephalopods are not the same,

each having its own suite of specific requirements. You can’t just get any old ceph and expect to keep it successfully. Squid need open water, octopus spend most of their time on the substrate or hidden in their dens, cuttlefish need both open water and aquascape to hide in, while nautilus seem to do better in taller tanks.

To make matters more complicated, any species of a given kind of cephalopod can have drastically different requirements from another species. For instance, Octopus hummelincki, is about the size of a tangerine and comes from seas with an average temperature of around 25°C.

Meanwhile, Enteroctopus dofleini can weigh in at 15kg with an arm span of two to four meters and lives at an average temperature of about 10°C. You’d need a very different aquarium system for each of these animals, even though they are both octopuses. It’s critical that you know what species you are going to get and plan accordingly.

Sourcing the right cephGetting a cephalopod can be difficult, and getting the species that you actually want can be even harder. These animals are always on supplier lists, but most collectors don’t really know the difference between them. Even the distributers make mistakes on what species they are sending.

I speak from experience when I tell you this is incredibly frustrating. Adjusting everything on the fly to

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take care of an animal (or ten) that you received, instead of the ones you ordered and prepared for, is not a good time.

Despite your best intentions, you can end up with a species that simply gets too big for you to be able to care for responsibly. Captive bred cephalopods reduce or eliminate that risk, but unfortunately they are few and far between; the market simply isn’t large enough to support plentiful octopus breeding.

Cephalopod housingAssuming you can get the ceph you want, you have to house it properly. These animals all start small, but they grow quickly, and you need to provide for them at each stage of their maturity.

A small ceph is best kept in a small tank, making feeding and health checks easier, because if you think that you will be able to assess the needs of a thumbnail-sized camouflage expert in a 200-liter tank you are living in a dream world. They are so good at blending in that your specimen can be sitting in plain sight, on a rock right in front of you, and you still won’t be able to see it. But the container that will keep the juvenile within your sights will not work for the full-grown adult’s needs.

While on the subject of housing, it’s important to remember that octopus will explore their environment, pull on everything, and climb out of the tank if there is a way for them to do it. They can squeeze through tiny gaps, as small as their beaks.

The stories about octopus leaving their tanks and coming back later are just stories — I know this because one commonly accepted fable was once attributed to me, and it did not happen. My experience is that if an octopus leaves its tank, you will likely find it dried out and covered in dust bunnies under your couch, if you find it at all.

This means that any tank needs to be escape proof. This can be tricky, and one public aquarist’s trick —using AstroTurf as an escape deterrent — only seems to reliably work for larger species of octopus.

Your lid will need to be tight fitting, preferably something with secure latches or weighted down. That latch or weight needs to be replaced every single time you open your system, as a ceph will see it’s opening and take it in an instant. Squid and cuttles can jump out of tanks, and need lids too.

Pump intakes and returns need to be screened. Not only can this stop an octopus from going in or out, but it will also prevent the potential tragedy of a squid or cuttlefish getting stuck on the intake.

Big belliesOnce your ceph is properly housed, you’ll need to feed it. A lot. Really. Whatever you think of as ‘a lot’, rest assured that they eat more than that.

Food needs also change as they grow, with babies needing live planktonic animals (emphasis on live), and lots of them. As they get older, their prey needs to get larger.

Ideally, you need access to an uninterrupted supply of live fish, crabs, shrimp, and, if you have an octopus, clams or other bivalves. All of these need to be the right size for your ceph’s current size. What was large enough last week, may not be large enough this week. (Editor’s note: In the UK, all vertebrates are protected under the Animal Welfare Act 2006, making the feeding of live fish unlawful.)

As consummate predators, cephs are notoriously difficult to transition to dead prey. Sometimes it can be done, but more often it cannot.

If it is ethically or practically problematic for you to feed live food to a cephalopod, then this is not the pet for you.

If you think a ceph is as smart as a dog, a pig, or a 3-year old child, I don’t see how you can justify keeping one in

a glass box in your living room

MARINE Cephalopods

Hiding in plain sight; octopus are masters of

camouflage.

Who’s watching who here?

An octopus mother guards her eggs.

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Note that all cephs are inefficient, messy eaters. They leave half eaten carcasses lying around, rotting and ruining your water quality, and yet they’re extremely sensitive to those same changes in water quality. You’ll be constantly picking up after them, testing, and doing water changes when things get bad.

Kids with extra legsAny fish or crustacean that you may want to keep with a ceph will likely either eat the ceph, or be eaten by it. Cephs usually eat other cephs, too, so good luck keeping two octopuses in the same tank. There are always reports of people that have been keeping fish with cephs, or even cephs with cephs for a month or two, but at some point, we stop hearing from them and can only assume that the pairing did not end well.

My shorthand for keeping tankmates with cephs — it works until it doesn’t. I don’t think the risks are worth it.

If you think of your cephs as children… only children who are escape experts, need to be housed in bedrooms of escalating size, who have huge, expensive appetites, who leave rotting food all over the place,

then you’ll have a fair insight into raising your cephalopod.

Live fast, die young The life motto for cephalopods is ‘live fast, die young’.

While cephs from cooler waters tend to live longer (a Giant pacific octopus can live up to seven years), the smaller tropical cephalopods that are easier to keep as pets live for just one or two years at best in the wild.

The animal that you have supported so lavishly, and devoted so much effort to, is not going to be with you for very long. This is critical to understand, and made more heartbreaking because most of the cephalopods that are available in the marine aquarium trade are wild caught adults, which may mean that they are already nearing the end of their natural lifespan. You will likely only have its company for a few months before it dies.

Worse still, you must prepare for the fact that the end of life for most cephalopods is disturbing.

The animal goes through what is called senescence, where it becomes lethargic, often ignores food, and can actually begin to rot while still alive, losing arms and sloughing its skin off in large chunks. This slide into death is terrible to watch, especially as the process is always irreversible.

In the wild, one would imagine that animals in this state would be quickly eaten by predators. In the sanctity of the home aquarium, there are no predators to do the eating.

Kind-hearted keepers hand feed their decaying pet, and in doing so, can keep them in this senescent state for months. We are unsure if a senescent cephalopod is suffering or not. Thus, the keeper must decide if it is in fact more humane to feed or to euthanize their beloved cephalopod when it reaches this stage.

Venomous bitesCephalopods have venomous bites to subdue their prey, but none are as famed as the Blue ringed octopus, Hapalochlaena sp. A single bite from a Blue ringed octopus contains enough venom to kill over 25 adult humans, and no antivenom treatment is available (or known). If you’re bitten, you’re on your own.

Astonishingly, there are no laws preventing the import and sale of Blue ringed octopus in the UK.

They have jet propulsion, arms, tentacles, suckers, a parrot-like beak, three hearts, weird shaped brains, great eye sight, amazing behaviours, a toxic bite, and can disappear in a cloud of ink when threatened. What’s not to love?

The ability for a cephalopod to change colour is down to the presence of tiny, colourful

chromatophores in the skin.These expand or contract

on command.

MARINE Cephalopods

Flamboyant cuttlefish are expensive but available.

An octopus inks the water in

response to a diver.

INSET ABOVE: Some octopus are famed for jar opening skills.

Octopus awaiting sale.

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Smart as a dog? There has been a recent surge in the number of popular books, articles and stories about the relative intelligence of cephs. A lot of these sources distort reality, and create overblown conclusions, but that is an article for another day.

Recently, on a reef keeping forum, someone posted “I love these and would love to have one someday. So cool, some of the smartest creatures on the planet”.

I don’t agree that cephs are the smartest creatures on the planet. But what if they were, or what if you really think they are? How can one ethically keep one of the smartest creatures on the planet in the confines of a home aquarium?

How big would the aquarium have to be for one of the smartest animals on the planet, if, let’s say, it’s the size of a tangerine? Even an aquarium 100x100x100cm seems doesn’t seem adequate, meaning most home aquaria would be way too small.

If you think a ceph is as smart as a dog, a pig, or a 3-year old child, I don’t see how you can justify keeping one in a glass box in your living room.

Personally, I think the intelligence of cephs is really hard to pin down. Then again, all intelligence, even in humans, is hard to pin down and quantify. I think some cephs are clever, but I do not believe that they are problem solvers in the same way that humans are.

Octopus don’t just open jars, or take pictures of people with a camera; they have to be trained to do those actions, and they often lose interest in those activities when any food stimulus is removed.

Octopus may not be doing anything special when they explore a new object or try to escape, and those kinds of actions may simply be how an octopus interacts with the world, no intelligence necessary.

It sure seems like they are clever, but if you sincerely believe that they are more than clever, you may also want to think through to the ethics of keeping one.

Are they for you? Cephalopods are challenging even for experienced aquarists. Before keeping any cephalopod, I suggest that you keep a reef tank successfully for at least a year.

There is a learning curve for keeping saltwater animals alive, and during that learning, horrible things can happen to an aquarium. Water quality can become toxic for many reasons. Oxygen can be depleted quickly. Salinity can crash or skyrocket over time. Cut your aquarium keeping teeth on easy to keep, cultured animals before attempting a difficult, messy eater like a cephalopod.

I guess this article is more about why you shouldn’t keep a ceph as a pet than why you should. But if, after all this, you are still interested, I suggest you visit www.tonmo.com, the most comprehensive cephalopod website around, to find out more.

There, you can read about different species and what their needs are, the best feeding and weaning onto dead food strategies, responsible sources for cephalopods, how to make your tank safe. You can also connect with other keepers with real life experience, in real time.

Only then, when you are experienced, prepared, and a just little crazy, do you have a shot at meeting the needs of your own tentacled, blue-blooded, ringed brained, clever ceph.

MARINE Cephalopods

Squid can be especially hard

to care for.

Octopus vulgaris, one of the more commonly available species.

Some octopus can grow to be gigantic creatures.

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