Volume 4, Number 37 - February 21, 2003
Why Do Goldfish Die?


   Goldfish might be the most popular pet in the United States but all too often the orange fish can be found floating at the top of their bowls. Why do goldfish die?

   "Like with many pets, people are often unaware of what goldfish really need, they don't get the advice they need and they don't know the right questions to ask," Paula Powell, director of husbandry at the Dallas World Aquarium, told UPI's Animal Health.

   "But even if the goldfish owner deals with water temperature, filtration and feeding, the fish could die because it was inbred or diseased -- some varieties do not do well."

   The goldfish, a member of the carp family, is a pretty hardy fish that with proper care can live 10-to-15 years and even up to 20 years, Powell said.

   What a pet owner should not do is to wake up one Saturday, decide having some goldfish would be a good idea, buy them and the aquarium and think it will take only a few hours on the weekend to set everything up.

   "There's a plethora of reference materials in libraries, pet stores and the Web on tropical fish and each fish deserves to have its owner do a little boning up because if properly maintained a goldfish can be a 10-year or more commitment," George Parsons, director of aquarium collections at the John G. Shedd Aquarium in Chicago, told UPI.

   When a pet owner determines what type of goldfish he or she wants, that person also must decide how many fish, what type of aquarium, what type of filter, vacuum, gravel or heater will be needed. Prepare to do some math.

   The Goldfish Sanctuary, a Web page on petlibrary.com, suggests using the following formula to determine how many fish can live in a
rectangular tank:

-- Surface Area = Length times Depth
-- Inches of goldfish = Surface Area divided by 30

   For example, if the tank is 18 inches long, 10 inches deep, and 10 inches high, multiply the length (18) by the depth (10), which equals 180 square inches of surface area. A goldfish needs 30 square inches of surface area for each inch of fish. This size tank could accommodate six one-inch fish, three two-inch fish, two three-inch fish, or a combination.

   "Purchase a tank as large as you can afford because the more water there is the more time people have before waste can hurt the fish," Parsons said. "The larger the tank the larger the margin of error."

   Placing a tank should be given consideration. A tank can be very heavy and should be placed on a strong surface. The water for a 10-gallon tank weighs 85 pounds; a 100-gallon tank weighs close to a half-ton, according to petlibrary.com.

   A tank should not be placed near a sunny window or a heater, but it should be near an electrical outlet, a little out of the way so people and other pets don't knock into it and somewhat close to a water faucet because water will have to be changed.

   "Remember that you will spill water around the tank inevitably, never put the tank on an appliance, antique, etc.," advises petlibrary.com. "Goldfish grow quickly, especially when cared for well, and they will need as much space as you can provide. A small tank or fishbowl does not provide as much space, and can sometimes stunt the growth of goldfish or cause other developmental problems."

   If gravel is chosen for the aquarium, it must be washed. Nonporous rocks can be added but Parsons warned gravel and rocks can trap food and fish waste, which makes cleaning more difficult.

   Petlibrary.com recommends purchasing rocks and plants from a pet dealer because rocks from nature can contain pollutants that could poison the fish.

   Most tap water contains chlorine, which needs to dissipate before being added to the tank. One way is to fill a bucket and let it stand for 24 hours before pouring it into the tank. This allows the water to warm to room temperature -- the right temperature for goldfish.

   Petlibrary.com recommends letting a new tank run for two weeks before adding fish so any faulty equipment or hidden leaks can be addressed.

   "Mass produced fish, often given as prizes in contests, live in crowded tanks, often aren't fed enough, may be inbred, and start out with a lot of strikes against them," Parsons said. "But a common goldfish is available in many grades in pet stores and other pet outlets."

   He warned never to buy a fish from a pet dealer where dead fish are floating in the tank "because the rest of the fish can be sick, or get sick later. Seek a knowledgeable and reputable pet dealer and never buy from a tank that is cloudy or has an odor." 

   Petlibrary.com also recommends taking fish home in a shaded container or perhaps in a picnic cooler, to maintain body temperature, so the fish are not stressed.

   "The tank water is best changed on a schedule such as twice a week. More often and it stresses the fish, less often and the fish won't have enough oxygen and won't eat," Parsons said. "Since it's impossible to tell if a goldfish is male or female, it is possible a couple could mate but it's unlikely because goldfish need temperature changes and seasonality to spawn."

   Despite research and careful planning, the fish still can get sick. How can you tell?

   "Some may never tell that a fish is sick until it starts floating at the top of the tank, but some hobbyists study their fish carefully and can detect signs and symptoms of disease," Dan Conklin, of the Florida Aquarium in Tampa, told UPI. "New fish added to an established tank should be guaranteed for a while to make sure they are not sick, because some fish may appear healthy but are carriers of disease."

   Conklin said the best place to get advice for a sick fish is the pet dealer because a there are few fish veterinarians and it makes no economic sense "to take a five-dollar fish to a vet that charges many times that amount."

   He said goldfish can die from water that is too hot or too cold, a buildup of ammonia from food not eaten or fishwaste and overfeeding, so although keeping a goldfish without filtration or heaters or fans is possible, it might not produce long-term results.

   Still, it is possible to keep a goldfish with gravel in a goldfish bowl. UPI's Animal Health babysat a goldfish that lived in a goldfish bowl for three weeks with aqua gravel. This important assignment was for a 7-year-old girl who had gone on vacation. The fish survived.
Copyright 2003 by United Press International.
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