Golden Oldie: Mr. Fish Is 27

Five years ago, Edith had a problem: Her goldfish of 25 years, Mr. Fish, had dropsy, a disease characterized by a swollen or hollow abdomen and in most cases fatal. In her last attempt to save her pet, on a whim, Edith wrote a message on GoldfishConnection asking for help.

Rick G. Copeland, the specialist at the goldfish site, recommended some Medi-Gold pellets. Two years later, at age 27, Mr. Fish swam around his tank as if his close call with death never happened.

Mr. Fish may not have the 49 year-old record of the oldest goldfish ever, but he's working on it. In the meantime, Mr. Fish is competing with the millions of other pet goldfish around the world.

Goldfish, which can grow to be up to two feet long, were one of the first fish to be domesticated dating as far back as 1162 when the Tang Dynasty dammed carp in rivers and goldfish were the result of a genetic mutation. Since then, the flow of changes associated with the pet is well studied in ichthyology.

Nowadays, goldfish are often linked to certain myths including not living long, and having an extra short memory span.

In the area of memory the popular show on the Discovery Channel, Mythbusters, showed that when it comes to recollection, the phrase "fish brain" may not be such a bad thing.

In the study, representatives from Mythbusters aimed to prove fish have a memory span over three seconds, by directing fish to swim a maze for an allotted period of time. As a result, the goldfish proved the "three second rule" wrong by being able to make their way through the maze during the time.

In a different 2003 study by the school of psychology at the University of Plymouth researchers showed goldfish to have a memory span of three months as well as the ability to decipher between colors shapes and sounds.

In the study that required fish to push a lever to get food, experts only turned the lever on for one hour at a specific time of the day. During the three month span, the fish learned how to activate the lever, more specifically, at the correct time.

Josh Kroot, who is the owner of several fish over 15 years of age, describes fish care as an involved process which begins with air. "Putting a fish in water with no oxygen is like buying a cat and then putting it underwater." Fish live much better when they have a bubbler, or some other device that helps oxygen dissolve into the water in the tank.

Kroot, who won his pets at a fair in middle school, admits that his goldfish have lived a shocking number of years more than he initially assumed. Many goldfish owners share the same pessimism about how long their fish will live.

In order to be on the same boat as fish owners like Kroot who have managed to keep goldfish alive for an extended period of time the steps are relatively simple. Proper maintenance means dechlorinating the water, putting oxygen into the tank and cleaning the water regularly because everyone poops — even fish.

Copeland, who provides goldfish maintenance tips in detail on GoldfishConnection, bubbles down the criteria for goldfish sustainability in one of his articles on the site. "With regular maintenance and a good diet your goldfish aquarium will be a pleasant addition to your home. Sit back, and enjoy the show!"

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Audrey Amara blogs for ScientificBlogging.com.