Cephalopods
Keeping cephalopods in captivity
What is a Cephalopod?
The order cephalopoda consists of four main types of animals: squid, cuttlefish, nautilus and octopus, the latter having the largest number of described species (~200). The word 'cephalopod' means head-foot, which is in reference to the fact that their limbs are attached onto their heads. Cephalopods are all invertebrates and are closely related to other molluscs like slugs and snails. They are found all over the World's oceans from the shallow tropical reefs to down in the deepest sea trenches. They show incredible variety and can weigh in at only one gram for the smallest species and up to 200 kilograms for the largest member of the group the Giant Pacific Octopus.
Octopuses and cuttlefish can be cared for in captivity with relative ease, as can nautiluses if you can get a deep enough tank with a good chiller! Squid, however, are still considered impossible for the home aquarium, as they require a huge cylindrical tank that is not transparent. These pelagic animals are not suited to captivity.
The Cephalopod Aquarium
Unfortunately there are no cephalopods that are suitable for a reef tank or for a mixedcommunity. A well maintained home aquarium would just be an expensive menu and any fish, shrimps and crabs would get eaten within a few days of adding the new inhabitant.Also bear in mind that many fish eat cephalopods and a small octopus is just as likely to disappear down the throat of a larger fish! So set the tank up as a specimen tank.
As octopuses are most commonly seen for sale the rest of this article will focus mainly on their husbandry
”The most commonly seen cephalopods for sale in the UK are octopuses, cuttlefish and nautiluses. Their husbandry is not too far removed from caring for any other marine species but differences lie more in the misinformation and poor species identification.
As long as a few aspects are catered for, I'd argue that these are the most interesting, if short lived, marine animals we could ever maintain in the home aquarium.”
Tank Requirements
1. Size matters
The aquarium should be as large as possible for the species that you intend to keep. The minimum size should be at least 36x18x18 (inches) to be used for small octopus species and as big as you can get after that.
Most cephalopods lead a solitary life and cannibalism is very common so it's best to keep only one per tank.
If possible use an aquarium with a sump. This protects all your equipment and reduces the different paths of escape quite significantly. The hood of the aquarium needs to be very tightly fitted. Even species that are not prone to climbing out have been known to try.
2. Water Parameters and Quality
Cephalopods have soft bodies and are essentially naked (except the nautilus that has an external shell). They have a huge surface area and therefore are very sensitive to water quality and pollutants like ammonia and nitrite, which should all be kept at zero. Nitrates seem to be tolerated to 50 - 100ppm with no apparent ill effects.
Copper is lethal and should be tested for before the octopus is added to an aquarium. Treat them like all other invertebrates in this respect.
An octopus produces approximately three times more ammonia than a fish of a similar mass; partly due to it's having three hearts and therefore three times the oxygen requirement of fish. As a result oxygen levels should always be kept as high as possible. To do this (and to remove all the excess waste) always use oversized filters and skimmers.When an octopus feels threatened it may eject viscous ink as a smoke screen. Although it is not poisonous it can and will coat gills and this may lead to asphyxiation. The ink can often be removed by catching it in a fine net but protein skimmers and good quality carbon is a must have! Always work slowly to avoid startling a new octopus.
Salinity is the other water quality parameter that must be controlled carefully. It is of paramount importance that the octopus aquarium has full strength seawater. Aim for 1.026 at all times, a lower salinity will kill them.
PH must be kept between 8 and 8.4 and it is always worthwhile to do a 25% water change on a fortnightly basis. Remember they do produce a lot of waste!
3. Aquascaping
Perhaps the most common reason for keeping an octopus is to witness its incredible brainpower, problem-solving skills and its willingness for interaction with its owner.
Its intelligence requires an enriched environment, that is lots of things to interest it in the aquarium. The simplest way to do this is to add lots of rocks and food grade quality plastic pipes of various diameters. The rocks should be glued into position to avoid landslides through the front of the aquarium as octopuses are very strong and like to re-arrange their own 'furniture'! The plastic pipes can be littered about the bottom of the tank. A large amount of shells and various small rocks should also be added as an octopus will appreciate being able to use them to make a door on its den. Caulerpa may also be used but avoid the temptation to add corals and anemones, they may sting the octopus but more likely, the octopus's activity will bury them.
The best substrate to use is a fine, well washed silver sand. Coral sand and similar substrates are too course for an octopus's sensitive skin and may damage them as they attempt to dig.
Most octopuses are nocturnal but they will generally change their habits in the home to suit times that we are active. A great way of breaking the ice with a new octopus and building a trusting relationship is at feeding time. If food is offered on a wooden or plastic stick at the same time each day, it wont be long before the arms come out the top of the tank to take food from your fingers! Also to help encourage the shyest of individuals, keep the lighting subdued. There is no need for metal halides, a small fluorescent strip is all that's needed on a timer for approximately 10 – 12 hours per day.
Enrichment comes in many guises so be creative. One of the most interesting ways of keeping an octopus entertained is by using various toys. This includes floating table tennis balls, Lego bricks, Star Wars action figures, plastic toy sharks and possibly any item of aquarium equipment, like a thermometer or cleaning magnet, you might have left in by accident! (Insure that anything added will not poison the water! Being 'food grade quality' or 'for babies' is a good guide)
4. Feeding :
In the wild an octopus's diet would consist mainly of crustaceans. This should always be reflected in the home aquarium. Although many of them will accept other food like feeder fish, this is not an ideal diet for a healthy octopus and feeder fish may have been treated with copper! An average size octopus of 18" arm span will eat approximately two 2" wide shore crabs every day or two. There are companies that supply food suitable for cephalopods.
5. Lifespan :
If ever there was a drawback to keeping cephalopods; it is this: the majority have a natural lifespan of somewhere between six months and two years. Some deep sea or coldwater species like Bathypolypus arcticus have been known to live for six years. It is your decision whether or not it all seems worth it.
6. Reproduction :
After becoming sexually mature, octopuses will mate and shortly afterwards the male dies. The female takes up residence in a well-enclosed den to lay her eggs. During the incubation period, which may be a month or more, the female often refuses to eat, and she will die shortly after the eggs hatch. The process of a cephalopod dying is calledsenescence. An unmated female will often lay infertile eggs in captivity and attempt to rear them. Unfortunately her fate is the same.
What species of Octopus are available?
What are we actually getting when we see that sucker covered arm waving at us from deep inside the live rock cavity in the dealer's tank? Buying an octopus in the UK is like the lottery. They are bought and sold with such meaningless names as 'brown octopus', 'common octopus', 'Bali Octopus' and a personal favourite 'Octopus Spp.'. This is not the fault of the shops however as octopuses are incredibly difficult to identify, even after a long time studying the group. They can change colour and body shape in the blink of an eye. One minute they may look 45cm wide and the next they've tucked themselves into a small ball. They can even lift flaps of skin on their bodies called papillae to allow them to resemble the rocks and plants surrounding them.
In all honesty there is no hard and fast octopus ID kit! Instead, here is a list of the more commonly imported species that you might find and their associated suitability. Always ask what part of the world the octopus came from as this helps to identify the species. Be warned though, you may never find out what species it is!
Octopus bocki :
A small retiring species frequently sold a 'Bali Octopus'. Best described as a dwarf it is short lived and most imported specimens are fully grown adults with maybe only weeks to live.
Octopus aculeatus :
This long armed species is frequently imported and has an arm span of some 30cms compared to a 4cm mantle. It has a good nature and will be diurnal once acclimatised.
Octopus vulgaris :
This is the common octopus. Be aware that the above two are often confused with juveniles of this species. This octopus can reach a large size of up to a 70cm span in captivity therefore a large tank is required. Notorious for climbing out so seal the tank carefully.
Octopus briareus :
This is the Caribbean or Florida Octopus. Settles in well to captive life. It normally has a reddish or bluish tinge and large eyes.
Octopus bimaculoides
The two-spot or Californian octopus is by far the best species of octopus to keep. It has a diurnal habit and doesn't get as large as vulgaris. This species is best kept at room temperature, as it is not a tropical species.
Species to avoid :
Avoid the temptation of buying the following species: The Blue Ringed OctopusHapalochlaena Spp., The Mimic Octopus and Wunderpus.
Blue rings are one of the World's most toxic marine animals with a bite that can kill a person. Frequently imported, they are poor travellers and are imported as short-lived adults. Their entire life span from hatching is naturally 6 months or so. The risks are not worth taking.
Wunderpus and Mimic octopuses do not yet have scientific names and have recently been seen in some TV documentaries. This has resulted in requests for captive specimens. Neither species is well documented in the wild and could in fact be rare. Both could potentially be toxic and the Mimic will never live up to its name in captivity refusing to act like it does in the wild. Again, normally imported as adults they are best left in the sea.
Cuttlefish and Nautiluses :
There are occasions when other species of cephalopod are available. The Common European cuttlefish (Sepia officinalis) is often available but its large size (up to 18") often limits its potential for home aquariums, a 6-foot tank is minimum for one adult!
Cuttlefish are generally very poor travellers and many die during exportation from the tropics. Success rates are very low and at this point they are perhaps best avoided. Sepia bandensis is the most commonly imported species - adult at 3" long.
Nautilus is often frequently seen and is another one to be avoided unless you are planning on setting up a very deep tank and can keep the temperature in the low sixties. Anything above that will kill them in a matter of time.
Further Reading
Websites:
The Octopus News Magazine Online (www.tonmo.com)
The Cephalopod Page (http://is.dal.ca/~ceph/TCP/index.html)
Caldwell R and Shaw C.D. 2002 Mimic Octopuses: Will we love them to death?(http://is.dal.ca/~ceph/TCP/mimic.html)
Monks N. 2002 The Perils of the Pearly Nautilus(http://is.dal.ca/~ceph/TCP/nautcon.html)
Biegler R. 2002 Begging in Cephalopods?
(http://is.dal.ca/~ceph/TCP/octopanrep.html)
Mather J. and Anderson R. 2000 Octopuses are Smart Suckers!
Caldwell R. 2000 Death in a Pretty Package: The Blue-Ringed Octopuses
Wood J.B. and Wood D.A. 1999 Enrichment for an Advanced Invertebrate
King, N. 2003 Octopus Basics
Dunlop, C. 2003 Cuttlefish Basics
Books
Norman M. 2000. Cephalopods A World Guide. ConchBooks.
Moynihan M. 1985 Communication and Noncommunication by cephalopods. IndianaUniversity Press
Boyle P R. 1991 The Care and Management of Cephalopods in the Laboratory. UFAW
Food Supplies
Aqualogistix, 01387 261 839 (can also seasonally supply native cephalopods UK only)
Thanks to Nancy King, Carol Sauer and Roy Caldwell for pictures!!!
feeding the octopus seattle aquarium
pet octopus playing/eating
Cephalopods list :
courtesy to : www.liveaquaria.com
Cuttlefish and octopi are masters of camouflage and can change color quickly. Both of these animals should be kept alone, as they are pure predators that will eventually devour their tank mates. They can be fed clams and pieces of shrimp or fish. Tight lids are required since they may propel or climb out of the aquarium.
Octopus - Assorted (Octopus sp.)
Minimum Tank Size: 70 gallons
Care Level: Expert Only
Temperament: Aggressive
Reef Compatible: No
Water Conditions: 72-78° F, dKH 8-12, pH 8.1-8.4, sg 1.023-1.025
Diet: Carnivore
Compatibility: View Chart
Origin: Indo-Pacific
Family: Octopodidae
The body of the Octopus is covered with chromatophores that allow it to blend in with any background by changing color. These Octopi from the Caribbean are brown with white spots when they are in a neutral mood. Unlike most animals, the Octopus has a rectangular pupil. It usually comes out at night to feed on small invertebrates or sleeping fish. It uses its eight tentacles to bring the catch to its beak-like mouth. Of its total length, the arms will represent about 80%, with the body comprising the rest.
The Octopus will do best in an aquarium if provided with plenty of live rock and ample hiding places and a large area in which to move. It prefers an aquarium with caves and medium to coarse substrate with low lighting levels. The ideal lighting for this aquarium is dim actinic lighting.
The Octopus can be surprisingly strong, so in the home aquarium, it is best to anchor the rocks, or even glue them together to keep the Octopus from toppling the rocks into the glass or onto itself. Cover all tank openings very well or it will try to escape. The Octopus is sensitive to high levels of nitrates and copper-based medications. It can be very difficult to acclimate into a new environment.
Always approach the Octopus slowly to avoid causing it to release its ink cloud in defense. In the aquarium, this release of ink will necessitate a large water change to avoid its death.
It is an extremely difficult species to breed in an aquarium.
The Octopus can be fed shrimp and mussel meat. It will also eat live crayfish and feeder shrimp. Any live foods should be fed spirulina based dry foods, plankton, and krill to enhance their nutritional value.
Please Note: Maximum size of Octopus sp. will vary upon assorted species. Octopus are measured by total body/tentacle length.
Approximate Purchase Size: Small 1 1/2" to 2"; Medium 2" to 3 1/4"; Large 3 1/4" to 4 1/2"; X Large 4 1/2" to 6"
Cuttlefish Husbandry: How do I keep a cuttlefish?
courtesy to : www.thecephalopodpage.org/
Parts one and two of this article on keeping cuttlefish described what cuttlefish are and how to purchase one. Our intrepid readers
(that is you) were left hanging with this question in their minds: How do I keep one? This section will bring our intrepid readers up to speed on the filtration, foods, tank sizes, tank mates and lighting needed to successfully keep one of the most interesting creatures on the planet, the common cuttlefish.
Filtration :
There is a plethora of books on the market that cover the science and art of setting up a marine aquarium. As this information is already readily available I will concentrate on specifics that apply to cephalopods. Hobbyists that are interested in keeping a cuttlefish and aren't yet familiar with the nitrogen cycle, the use of protein skimmers, pH, salinity, and the importance of regularly testing water quality are strongly encouraged to read several books on the subject first. Cephalopods aren't as hard to keep as many think; however, I'd advise against keeping them in your first marine aquarium.
Cuttlefish should be provided with well oxygenated, clean water. They are very sensitive to heavy metals, especially copper. Copper probes or chiller coils can not be used and metals should be kept out of the aquarium. 'Aquarium safe metals like stainless steel and titanium may be OK but should be kept to a minimum.
Since cuttlefish grow fast, eat a lot, and are active, it would be a good idea to slightly over-filter the tank. Canister filters, turf scrubbers, hang on the backs, wet/drys, fluidized bed filters or whatever the latest flavor of filter is, can all be used on a cuttlefish tank. Undergravel filters are not advised as cuttlefish often dig in gravel which could create dead spots. Also, the cuttlefish may get stressed when the gravel is cleaned. If you have small cuttlefish, place a sponge over the filter intake so that the cuttlefish does not get pinned to it.
No matter what you use as a filter, I would advise adding a protein skimmer, even if it is just a small one. Protein skimmers remove some waste products even before they decay into ammonia, and they also create a lot of water/air surface area which keeps the water well oxygenated. Carbon and/or resins like polyfilter can also be added in the filter. They remove unwanted organics as well as ink and heavy metals. Water changes of about 20% should be done monthly, and pH, salinity, ammonia, and nitrite should be monitored. Cuttlefish will ink if stressed. The ink should be siphoned out of the aquarium, and the cause of the stress should be located and removed if possible.
Cuttlefish should be housed in well established tanks—preferably ones that have been up and running successfully, with a biological load in them, for at least 3-4 months.
Lighting :
Cuttlefish don't need any special kind of lighting. Keeping the lights to a minimum also reduces the growth of algae and one or two standard flourescent bulbs will suffice. Those keeping reef tanks and using much brighter lighting need not worry as the intense lighting will not bother cuttlefish; rapid increases in light level will though. New cuttlefish are especially prone to inking if their environment rapidly changes. For example, if someone bumps the tank or the lights come on suddenly they may ink. In addition to inking, nervous cuttlefish may react by jetting and hitting the side of the aquarium. This can cause the delicate skin to rip, exposing the muscle below, and is termed 'butt burn' by Dr. Jean Boul. This lesion can get worse if the animal continues to jet into the side of the tank and it can become infected. If you see this happening turn on the lights slowly and try not to startle your cuttlefish.
Temperature :
Cephalopods live from the poles to the tropics and from the intertidal to the abyss. Sepia officinalis isn't a tropical species and it should be kept between 15-25°C (59-77°F). If your live in a warm climate, a fan blowing over the top of the water and moderate lighting is often all that is needed to cool a tank down enough forSepia officinalis. If you buy a cuttlefish from a pet store try to find out where it was collected so you can make an educated guess regarding the temperature at which to keep it.
Tankmates :
Cuttlefish such as Sepia officinals, are more social than octopuses and are generally found in loose groups in nature. A group of cuttlefish can be raised together in a large aquarium. However, if an adult male that has been raised by himself is introduced to another adult male they are likely to fight and may damage each other. Keep in mind that if food is limited, cephalopods can be cannibalistic.
Fish one intends to keep should not be kept with cuttlefish, they will either become dinner for them or vice versa. Like myself, cuttlefish will devour any crustacean in sight, so please keep them out of their tank unless they are intended as food. Cuttlefish might not be able to get hermit crabs out of their shells but they will certainly try. They generally leave echinoderms alone (sea stars, brittle stars, sea cucumbers) though there are a few exceptions. Some cephalopods will eat bivalves, snails and worms while others do not. They won't try to eat the anthazoans (coral, sea anemones, zooanthids, etc), sponges and tunicates (sea squirts) found in reef tanks. However, some of the more aggressive hard corals can sting them. This is more likely to occur to octopuses as they usually are in contact with the bottom. Both cuttlefish and octopuses may move things like gravel and small rocks around.
Tank size :
Tank size, of course, depends on the size, and the potential size of the animals that you are planning to keep. Some species like Euprymna scolopes, are small and can easily be kept in a ten gallon aquarium. Other species like Sepia officinalis get much larger - one of ours is approximately 15 inches long. I'd recommend at least a 40 gallon aquarium for a single Sepia officinalis. A larger tank certainly wouldn't hurt. (UPDATE/CORECTION: ACTUALLY I WOULD RECOMMEND 100 GALLONS PER ADULT CUTTELFISH. GROUPS OF SMALLER CUTTLEFISH CAN EASILY BE HELD IN MUCH SMALLER TANKS BUT AN ADULT COMMON CUTTLEFISH NEEDS MORE ROOM THAN I PREVIOUSLY INDICATED. ADULT MALES MAY NEED TO BE SEPERATED EVEN IN SYSTEM THAT IS 15 M DIAMETER.)
Feeding :
Cuttlefish primarily eat live marine fish and crustaceans in nature and these are ideal foods for them in captivity as well. If you are lucky enough to live near a beach, estuary, or marine bait shop and can give your cephalopod live food it will love you forever. Healthy cephalopods eagerly go after live food and seem to be always hungry. A cuttlefish that hasn't eaten in a few days and does not go after live food is very ill. Unlike most octopuses, cuttlefish will still eagerly take food after they start laying eggs.
Luckily for inland aquarists, adult cuttlefish will often take frozen food such as frozen shrimp and fish and such foods can make up their staple diet. Variety is the spice of life for cephalopods as well as humans. Most large grocery stores have a good selection of frozen marine shrimp, crab, lobster, mussels, squid, and fish to chose from. It may be necessary, especially at first, to skewer frozen food and swim it around the tank to get a feeding reaction. If you have been feeding frozen food for a while and are having problems feeding try temporarily switching to live food. Live freshwater crustaceans such as freshwater shrimp, crayfish and fish can also be used. Although live freshwater foods are not quite as nutritious as their marine cousins, cephalopods will grow and thrive on them, and they do elicit a healthy feeding response.
Cuttlefish do eat a lot, but like most marine creatures they can be overfed. A healthy cuttlefish that feels secure in its surroundings is very likely to 'beg' for food and train its owner to give it more than it needs - especially if it is being fed live food. Excess, uneaten food should be removed, as it will rot and may cause an ammonia spike. Proportions should also be reduced past the point where the little beast is able to eat everything. If your cuttlefish isn't eating very much of the frozen food that you are offering, switch back to live food for a while.
Underfeeding can also be a problem. Cephalopods can be cannibalistic especially when they are underfed. Boletzky and Hanlon (1983) report that one of the first signs of under feeding is the appearance of a dark longitudinal stripe on the dorsal (top or upper) side of the mantle.
Cuttlefish generally eat the meat out from crustaceans and discard the shells, but they ingest entire fish. Cuttlefish have a large cuttlebone, and they may get some of the calcium for it from their diet. It might be a good idea to occasionally fed them whole fish, either live or frozen.
Now you not only know where to purchase a cuttlefish, but what to feed one, how to filter the tank and what tank mates are likely to remain alive. There is only one question left. The question that all serious marine aquarists in this modern age want to know. The question that proves beyond a doubt to our spouses that our 'curiosity' with marine life goes well into the realm of obsession. The question that separates the amateurs from the truly addicted aquarists. The question: Can I breed them? See ya next month for the final section of this article and the answer to that question.
References :
Boletzky S.v. 1983 Sepia officinalis. In: Boyle, P.R. (ed) Cephalopod life Cycles, vol 1. Academic Press, London. 31-52.
Boletzky S.v. and Hanlon R.T. 1983. A review of the laboratory maintenance, rearing and culture of cephalopod molluscs. Memoirs of the National Museum Victoria, 44: 147-187.
Boyle P.R. 1991 The UFAW handbook on the care and management of cephalopods in the laboratory. Universities Federation for Animal Welfare.
Articles Reference
Wood, J. B. 1998 Cuttlefish Husbandry. Part III; How do I keep a cuttlefish? Freshwater and Marine Aquarium Magazine. vol 21, no 9. Reprinted in: The Cephalopod Page. Wood, J. B. Ed.
Cuttlefish Husbandry: How do cuttlefish reproduce?
courtesy to : www.thecephalopodpage.org/
You have read parts I, II and III of this article and already know where to purchase a cuttlefish and how to keep one. Now you want to know the hard core details, you want to delve into the sex life and reproductive biology of a creature that has been described as the closest thing we have to a living alien.
Many cephalopods are short lived and only reproduce once. For example, most tropical and semi tropical species of octopus live for a year or so, and the females die after their single brood of eggs hatch. The males also have short life spans. This strategy seems odd to us; people tend to associate long life spans and iteroparity (producing offspring more than once) with intelligence. It seems a waste for something as intelligent as a cephalopod to have such a short life cycle. Mammals, however, are just one of many groups of animals and we should not expect other groups to have the same reproductive strategies that we do.
The cephalopod strategy can best be summed up by the phrase 'live fast and die young', though there are a few exceptions. Sepia officinalis is fairly long lived for a cephalopod, they live for 1.5 to 2 years, depending primarily on temperature. Because of their short life spans, it isn't uncommon for a cephalopod to reach maturity and reproduce in a home aquarium.
OK, let's assume your goal is to mate cuttlefish and produce a second generation. Perhaps you want to help fill in the colossal demand that will surely appear once this article goes to print. Or perhaps you have heard of cephalopods' amazing cognitive abilities and wanted to train a small army of them to do the dishes, walk the dog or buy and sell securities.
The first thing you need is... correct! A male and a female cuttlefish. Adult cuttlefish are hard to sex and the only 100% reliable way to sex a live one is to see it mating or laying eggs. However, a male cuttlefish might aggressively display to a reflection of itself in a mirror. The aggressive display of cuttlefish consists of a vivid zebra stripped pattern, bulging eyes, and often lining up parallel to its reflection. Unfortunately, females will also occasionally do this display. We tried this method and lets just say that the 'flip a quarter method' would likely have been more productive. Another and more effective test, is to put two cuttlefish in a tank that is divided by a clear pane of plexiglass. If one cuttlefish displays the aggressive pattern and rushes head first at the other cuttlefish which is not striped and is brownish in color, you probably have a male and a female. Cuttlefish mate head to head. If you have two males they should both do the aggressive pattern and line up parallel to each other to size each other up. Unfortunately, if you put two males together that haven't grown up together they may fight. They should go through their assessment display first which gives you time to separate them.
Since sexing techniques are far from reliable, the best way to get mated cuttlefish is to raise a group together in a large aquarium. They can tell each others sex by sight and will mate readily when they are old enough to do so. By keeping several cuttlefish you are increasing the chances that you will have at least one male and one female. You will need a very large tank to raise a group of Sepia officinalis to maturity.
Unlike octopuses, female cuttlefish will lay eggs and continue to eat for several months. The large eggs are laid one at a time. My cuttlefish attached her eggs to the airline and incoming water tubing. The female incorporates ink into the egg case when she lays the eggs causing them to look a bit like a cluster of dark grapes. The eggs take approximately 50 days to develop depending on temperature.
Hatchling Sepia officinalis are one of the easiest species of cephalopods to rear. Currently, the National Research Center for Cephalopods has a 14th generation of consecutively lab raised Sepia officinalis. The hatchlings are fully formed versions of their parents at birth and do not go though a difficult to rear planktonic phase like many marine creatures do.
Hatchling cephalopods require live food. While Sepia officinalis is the only cephalopod species that has been reared through their youth on Artemia, I do not recommend using Artemia unless there are no other options as many of the cuttlefish will die and the growth rates of the survivors will be retarded. Mysid shrimp, small marine fish, amphipods, isopods, and other small live marine crustaceans and fish are ideal first foods. Bill Mebane, a scientist at the Marine Biological Lab at Wood's Hole, has had great success using newly hatched killifish (Fundulis grandis, sorry killifish lovers!) to feed hatchling cuttlefish. Killifish eggs can be ordered from Gulf Coast Minnows; their address is at the end of this article. The eggs can be shipped damp, are inexpensive, and are an especially great option for land locked aquarists. Essentially they are the Artemia of the fish world. I've heard that some aquarium stores are starting to regularly offer live amphipods (also known as scuds, hoppers, or beach fleas) for sale; these are the main food I have using to fed my hatchling cuttlefish.
Foods should be 0.5 to 1.5 times the mantle length of cuttlefish. Freshwater fish, fresh water amphipods and fresh water shrimp could be tried if live marine foods are not available. Artemia should only be tried as a last resort.
Hatchlings grow very quickly and will eat a lot of food. Most hatchling cephalopods double their weight every week or so for the first few months. To put that kind of growth rate into perspective, imagine how big you would be if your weight doubled every week! Food quality and quantity are very important at this point. If you have too many hatchlings it would be a good idea to farm some out to friends instead of starving all of them. If you need some friends, I'm sure there are plenty of people on Ceph Group willing to adopt your excess cuttlefish.
Hatchlings can be reared as a group in a small tank, or in a floating container in your main tank. They will associate you with food and take food from tweezers, a skewer or your hand at a very young age. If all goes well, your cephalopods will quickly out grow their rearing containers and you can train them in international espionage and unleash them on the world.
Conclusion :
In the last 20 years scientists have learned a lot about the husbandry requirements of cephalopods but unfortunately little of this information has filtered down to aquarists. Because of this, much incorrect or outdated information and advice on keeping cephalopods exits in the hobby; there still are no books for aquarists on keeping cephalopods. Hopefully articles such as this will convince aquarists to consider keeping a pet cephalopod. The common cuttlefish, Sepia officinalis, is an excellent choice for a new pet.
More information :
Cephalopod life cycles and The UFAW handbook on the care & management of cephalopods in the laboratory are good books on cephalopods though they are not written for hobbyists. Hanlon and Messenger have recently published an excellent book on cephalopod behavior. All of these books are listed in the references.
Acknowledgments :
Thanks to my wife Deborah and also to Erika Chen for commenting on this publication.
Addresses:
Gulf Coast Minnows, Inc.
110 Bobcat Lane
Thibodaux, LA 70301
(504) 447-7322
National Research Center for Cephalopods (NRCC)
Marine Biomedical Institute
301 University Blvd.
Galveston, TX 77555-1163
Part I - What is a Cuttlefish anyway?
References
Boyle P.R. 1991 The UFAW handbook on the care and management of cephalopods in the laboratory. Universities Federation for Animal Welfare.Boyle P.R. (ed) 1983 Cephalopod life cycles, vol 1. Academic Press, London.Boyle P.R. (ed) 1987 Cephalopod life cycles, vol 2. Academic Press, London.DeRush R.H., Forsythe J.W., DiMarco, F.P. and Hanlon R.T. 1989 Alternative diets for maintaining and rearing cephalopods in captivity. Laboratory animal science. 39(4): 306-312.Hanlon R.T. and Messenger J.B. 1996 Cephalopod Behavior. Cambridge University Press, Cambridge.O'Dor R.K. and Webber D.M. 1986 The constraints on cephalopods; why squid aren't fish. Vie Milieu 35: 267-271.Wood, J.B. 1994 Don't fear the raptor; an octopus in the home aquarium. Freshwater and Marine Aquarium Magazine. 17(4).
Articles Reference
Wood, J. B. 1998 Cuttlefish Husbandry. Part IV; How do cuttlefish reproduce? Freshwater and Marine Aquarium Magazine. vol 21, no 10. Reprinted in: The Cephalopod Page. Wood, J. B. Ed.
Caring for Cuttlefish
Flamboyant Cuttlefish at the Aquarium of the Pacific