bubble fish

Question
I just bought a bubble fish and was told fish like these were created by cross breeding. I was hoping you could quench my curiosity and tell me what fish were bred to make these interesting creatures. Do the fluid filled bubble sacs hold any useful purpose for the fish-like to help it feed??? What is the fluid in the sacs?

Answer
Hi Meghan;

Your bubble fish is really a "Bubble-Eye Goldfish" and not actually a cross-breed of any other type. They are a very nice sweet goldfish with personality and one of my personal favorites. Bubble-eyes are one of many ornamental types of goldfish that are developed by "selective breeding" of other goldfish that share certain traits or mutations. He's all goldfish and requires the same care and feeding that other goldfish do, except his tank should not have sharp objects that could injure his bubbles. If your tank is newly set up you will want to know about "The Break-in Period" too. Here is my own page about it so you can get him through this difficult process;

http://www.xanga.com/Expert_Fish_Help

The sacs or "bladders" under his eyes are just filled with his own body fluid. A baby bubble-eye starts to develop them when he is 6 to 9 months old. They serve no purpose whatsoever, it is simply ornamental. Bubbles are a genetic mutation that ornamental fish breeders in China noticed many generations ago and bred fish together that had it. The babies of the selectively bred parents had a stronger tendency and probably more enhanced bubbles so some of those were bred together to strengthen the tendency in the next generation, and so on and so on. Parents are also selected for uniformity of their sacs, color, and dorsal fin absence, just to name a few other traits. This is a simplified explanation but that's basically how it's done. It is the same with Telescopes, Celestials, Orandas, Lionheads, etc. All goldfish, just selectively bred according to their unique mutations and traits. It takes many years but goldfish are actually very genetically "pliable". Their mutations are much easier and quicker to enhance through the selective breeding process than other types of fish.

To keep your fancy goldfish healthy, he needs at least a ten gallon tank with a good filter and a weekly 25% water change. He needs veggies in his diet too, just like other goldfish. Here are some sites that help you know more about goldfish and how to care for bubble-eyes;

http://www.firsttankguide.net/goldfish.php

http://www.kokosgoldfish.com/bubbleeyes.html

http://animal-world.com/encyclo/fresh/goldfish/BubbleEye.php

http://www.bristol-aquarists.org.uk/goldfish/bubble/bubble.htm

http://www.aquaticcommunity.com/goldfish/bubbleeye.php

http://en.wikipedia.org/wiki/Bubble_eye

Have fun!

At Your Service;
Chris Robbins