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Related FAQs: Finding Nemo Input

Caring for the Fish of Finding Nemo


By Steven Pro 


            With all the publicity of Finding Nemo, there is sure to be a considerable amount of interest in aquarium keeping and in particular, the care of Clownfish and Tangs.  Young, impressionable children are going to be clamoring for their parents to buy them their very own Marlin, Nemo, and Dory.  This article is intended to give a beginner some of the basic information on the care and environment required to properly house these types of pets. 

            Luckily, Marlin and Nemo are actually very popular and hardy fish that can be cared for relatively easily.  They are sold under several common names; common Clownfish, Clown Anemonefish, false Clown Anemonefish, Percula Clownfish, or false Percula Clownfish, but their scientific name is Amphiprion ocellaris or more casually as the Ocellaris Clownfish.  These fish are naturally found throughout the Eastern Indian Ocean and Western Pacific and make an excellent addition for a beginner's first marine aquarium.  They have an interesting, undulating swimming pattern, bright coloration, a great personality, and grow to a manageable size; making them a favorite of all saltwater enthusiasts.  Clownfish are most recognized for their symbiotic association with anemones, although they do not require an anemone to be happy and healthy in captivity.  Clownfish are almost always found within the protection of an anemone in the wild, rarely venturing more than three feet from their home.  This close association and tendency for limited travel make them a perfect subject for life in the confines of aquaria. 

The anemones are another story.  Currently, there is no guaranteed methodology to succeed in keeping an anemone alive, with most all anemones removed from the ocean perishing in under a year.  This is truly appalling given that anemones are nearly immortal in the wild, have a low rate of reproduction, limited distribution, and provide critical protection from predation for Clownfishes in the wild.  Luckily, like I said above, clownfish adapt quite readily to life in the aquarium without an anemone because they don't need the protection from predators in an aquarium.  Many times they merely take shelter near a small cave, or live with an artificial anemone, or accept an unnatural surrogate such as a Leather Coral (Sarcophyton or Lobophytum). 

The other factor that makes Clownfish such a good candidate for a beginner's aquarium is that a large number of them are currently being bred in captivity.  These farm raised fish are hardier because they do not have to survive the rigors of transport from the Indo-Pacific, a lot less disease prone and considerably less aggressive than their wild counterparts, just as colorful, already accustomed to people and prepared foods, and are an environmentally conscientious choice.  For all these reasons and more, I always urge hobbyists to purchase captive raised fish whenever possible. 

            Clownfish will usually take to eating just about any food offered.  A high-quality, dry, pellet food would be a good standard offering, supplemented by some frozen foods.  Frozen mysis shrimp, plankton, and bloodworms as well as any of the frozen food mixes (example: Ocean Nutrition's Formula One) are all good choices that should be offered at least once per week.  The frozen food should be defrosted for a few minutes in a small cup containing some water from the aquarium.  Heating the frozen food in a microwave destroys some of the vitamin content of the food and should be avoided.  Simply allowing it to sit out for a minute or two on a counter will sufficiently thaw the food.  As it is defrosting, it would be a good idea to add some additional vitamin supplements to the cup.  This will allow time for the frozen food to absorb the vitamins and provide the fish with a little extra help to maintain and boost their natural coloration.  Products like Boyd's Vita-Chem and American Marine Selcon would be excellent choices.  If the local fish store does not carry these brands, I am sure one of the knowledgeable employees there will be able to help find a suitable substitute. 

            If your only goal is to keep two Clownfishes, you are in luck as the initial investment will not be too great.  This is, of course, a relative statement.  I have put together some larger saltwater tanks that run into the thousands, even tens of thousands of dollars.  For the setup I outlined in the sidebar, you are probably looking at just several hundred dollars. 

While two Clownfishes can live in a tank as small as 10 gallons, most beginning aquarists will be more successful starting off with something a bit larger.  The reason for this is simple; say there is a minor mishap.  An error diluted over 10 gallons could be much more tragic than the same error diluted over twice the volume.  For that reason, I would strongly urge you to purchase a minimum of a 20-gallon tank.  And, of course, something larger will give you more options for adding additional pets in the future. 

Once you have selected and purchased a suitable size aquarium, choose a location in your home where it can be easily viewed and enjoyed.  While a child may desire to have the tank in their room, the rest of the family cannot see it, appreciate it, nor notice when something is going awry.  A living room or family room is a much better choice. 

There are a few additional considerations as far as placement goes.  The aquarium should not be near a window, as direct sunlight may fuel unwanted algae and necessitate frequent cleaning.  Also, drafts from windows or heating and cooling ducts could cause significant temperature fluctuations in a smaller aquarium.  Dramatic shifts in temperature are unhealthy for the inhabitants and should be avoided.  Third, be sure that the tank and stand are flat and level.  It is much easier to take care of this now while everything is empty.  Another thing that is much easier to do while the tank is empty is attach the background.  This will permit removing the tank or spinning it around to make it much more convenient to securely adhere the background.  Fourth, consider that having the tank located somewhere near a sink will make maintenance that much easier and more likely to get done.  No matter what your child says, you know you are going to be the one taking care of this pet.  Make it as easy on yourself as possible.  Lastly, the tank must be situated near an electrical outlet and remember to leave space behind the aquarium for the filters that will hang off of the back and for the wires. 

            Once an appropriate location has been decided upon, the assembly can begin.  Please note that no fish should be brought home the same day that the equipment is purchased.  Their new home must be setup first or else the fish could be killed due to insufficiently mix saltwater or some sort of mechanical problem - and break the child's heart.  The first thing to do would be to begin treating the tap water for chlorine and mixing the saltwater in buckets.  Do not use the bucket that you use to mop the floor, as any kind of cleaning chemicals can be fatal to your fish.  Purchase several buckets for fish use only.  Follow the directions on the labels, but realize that it is much easier to add just a bit more salt to the mix than it is to dilute water with too high a concentration of salt.  And please always check with a clean hydrometer (salt concentration testing device) what the actual salinity is.  Don't just rely on the instructions on the salt mix.  The exact amount of salt is crucial to the proper health of your pet fish. 

            What I am going to describe for you is what is referred to as a Fish Only With Live Rock setup or a FOWLR display.  It is a more natural methodology for caring for ornamental marine tropicals.  While there are many other acceptable ways to provide a proper environment, I prefer this method, as it is functional, relatively easy to maintain in comparison to other methodologies, and aesthetically pleasing. 

Equipment Checklist for a Clownfish only tank (Sidebar)


q       Standard 20-gallon tank

q       Background (I prefer a solid color, blue or black, as this shows the fish better)

q       Hood with fluorescent light (fluorescent lighting gives the tank a far better color and appearance than incandescent lighting)

q       Aquarium stand (not a rickety end table)

q       20 pounds of live sand

q       30 pounds of live rock

q       Protein skimmer (A Red Sea Prizm would be a fine choice for up to a 30 gallon tank.  If you think you may upgrade to a larger tank in the near future an Aqua-C Remora, CPR Bak-Pak 2R, or Precision Marine HOT-1 would be a good investment.)

q       Two ~100 gallon per hour powerheads for water motion (models from Aquarium Systems or Hagen are good choices)

q       100-watt submersible heater (Aquarium Systems, Ebo-Jager, Marineland, and Tetra all make fine units)

q       Thermometer

q       Test kits for pH, ammonia, nitrite, and nitrate (Aquarium Pharmaceuticals Dry-Tab test kits are reliable and easy to use)

q       Hydrometer

q       Salt mix (I have always used and liked Instant Ocean or Reef Crystals)

q       Dechlorinater

q       Buckets for mixing

q       Gravel siphon for changing water

q       Algae pad/scraper (be sure to get a model appropriate for the tank's material - glass or acrylic)

q       Net

q       Power strip (like the ones used for computers) to plug in all the electrical devices 

            Into the aquarium add enough live sand so that when it is evenly distributed it is approximately one inch deep.  At this point, I would put all the mechanicals in place; pumps, heater, and protein skimmer.  This way when you add your live rock and decorations you can attempt to cover and disguise this items.  Just don't plug anything on yet.  Most all aquarium devices are designed to operate submersed in water.  Operating in air (what is referred to as running dry) will damage them.  Now place the live rock into the aquarium.  Be sure to work the first few pieces down into the sand so that they end up resting securely on the bottom.  This will prevent settling of the rockwork and provide a stable footing for subsequently higher placed pieces.  Continue adding the rest of the rock while attempting to create an open looking display.  Try to build caves, crevices, and overhangs versus a brick wall.  Once you are satisfied with the layout and look of the aquascaping, you can begin to pour in the mixed saltwater.  Try to avoid dumping the water directly onto the sand, as this will quickly turn the display into a cloudy mess.  A trick it to place a small bowl or plate onto the sand and then to slowly pour the water onto it.  This basically cushions and absorbs the force of the falling water.  When the tank is filled, you can turn everything on and see your finished masterpiece. 

            Now that it is full and running you are probably going to be tempted to run out and buy some fish to stock it.  Don't do this just yet.  You have to allow the live rock and sand time to fully cure and the tank time to cycle.  This means merely giving the system time to develop the bacteria that will help to support the tank's inhabitants.  This can take anywhere from one week to one month depending on the live rock and sand.  Use the test kits to monitor the progress.  Once the ammonia and nitrite are both zero and holding, you can add your fish few fish.  In the case of the twenty-gallon tank outlined here, that would be a pair of small Ocellaris Clownfish.  After one month, if ammonia and nitrite are still absent, you could introduce another tank mate or two. 

            Unfortunately, while properly housing Marlin and Nemo is going to be relatively easy and inexpensive, bringing home Dory is another matter completely.  Dory-type fish are known by whole host of common names in the hobby: Blue Regal Tang, Hippo Tang, Pacific Blue Surgeonfish, Palette Tang, or Blue Yellowtail Surgeonfish.  The scientific name for this fish is Paracanthurs hepatus.  One of the problems with keeping one of these fish is their full-grown size.  They grow up to a foot long as adults!  While there are many juveniles offered for sale, not being prepared to house it as an adult is inappropriate.  The smallest appropriate tank for one of these is 90 gallons.  Anything smaller than that is cruel.  Think of it much in the same way as caring for a dog.  If you were to bring home a puppy Saint Bernard and try to keep it in a cage/kennel meant for a Toy Poodle, the ASPCA would have you arrested for animal cruelty.  Fish should be thought of in the same way - as cherished family pets. 

            One of the other problems associated with Hepatus Tangs is their tendency to become sickly.  They have a strong propensity to contract a variety of parasitic infections, especially marine Ich or Cryptocaryon.  This infection is so prevalent with this species that many people refer to this fish as the "Ich magnet".  There is another health concern with this particular fish.  There is a practice in some parts of the world, namely the Philippines and Indonesia, of collecting some fish using cyanide to "temporarily anesthetize" the fish and make it easier to catch.  I put these words in quotes because it does far more than that.  The cyanide does permanent damage to the fish and many times while they survive the initial exposure, death is almost certain later.  Currently there are several trade associations working to eliminate this practice, but unfortunately it is still with us.  Purchasing Hepatus Tangs that originate from Hawaii, or if they come from elsewhere, are guaranteed net caught (you may be able to find a limited number of fish that have been certified net caught by the Marine Aquarium Council, MAC for short), or were raised from larvae is a reasonable assurance that this particular specimen is safe from cyanide poisoning. 

            If you intend to house a Dory-type fish, I would still recommend a FOWLR setup.  It is just that everything needs to be bigger; aquarium, pumps, protein skimmer, and amounts of live rock and sand.  Again, a competent, experienced aquarium professional should be able to help guide you. 

One last piece of "equipment" I would like to mention is a good book.  While I have hopefully outlined much of the basics here, this is a rather broad stroke at a vast and addictive hobby.  If long-term success is desired, I would recommend investing in a couple of good books.  Any of the publications mentioned in the bibliography would be fine, but I wanted to point out two in particular.  Michael Paletta's "The New Marine Aquarium" is an excellent book for the general beginning saltwater hobbyist.  It is only 140 pages or so, with pictures and illustrations, and written in very comfortable language, so it should be a quick read.  It will provide a more in depth discussion than what could be provide here on topics such as equipment selection, setup, compatibility issues with fishes, selection of healthy individuals, some disease diagnosis and treatment information, and ongoing maintenance.  Scott Michael's "Marine Fishes" is a very handy reference covering the 500+ most popular saltwater aquarium fishes.  It has pictures and a brief summary for each fish discussing adult size, suitable volume aquarium, feeding, hardiness, compatibility, and general care notes. 

Hopefully, I have put you on the right road to becoming a successful hobbyist.  Like anything in life, the more you put into it, the more you will get back out of it.  Be sure to continue to read more about aquarium keeping.  The more educated you are, the better your tank will look, the healthier and longer lived your fish will be, and the fish won't dread coming home with you like they did with Darla.



Allen, Dr. Gerald R. and Daphne G. Fautin. 1994. Anemone Fishes and Their Host Sea Anemones. Tetra Press: Blacksburg, VA. 

Fenner, Robert M. 1998. The Conscientious Marine Aquarist. Microcosm Ltd: Shelburne, Vermont. 

Michael, Scott. 2001. Marine Fishes. T.F.H. Publications, Inc.: Neptune City, NJ. 

Paletta, Michael. 2001. The New Marine Aquarium. T.F.H. Publications, Inc.: Neptune City, NJ. 

Tullock, John. 2002. "Anemonefishes: The First Part." Tropical Fish Hobbyist, March 2002. 

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