Feeder Goldfish and Aquarium Predators
Many aquarium hobbyists are drawn towards maintaining predatory species because they find it interesting to watch them consume other fish. There are endless possibilities of aquarium predators including but not limited to large cichlids, catfish, piranhas and gars. Most pet stores and local aquarium shops sell feeder goldfish for sufficing the appetites of aquarium predators. Feeder goldfish are simply common goldfish, and they are often offered in large numbers at low prices to attract hobbyists to feed them to their predatory fish. In fact most pet stores and aquarium shops offer an individual price for single feeder goldfish and a price by the dozen which results in the cost being less per fish.
What many hobbyists may not realize is that feeder goldfish are very risky to feed to aquarium predators as they often introduce disease to the aquarium and its prized inhabitants. Feeder goldfish are bred in massive quantities and shipped in large numbers. When I worked at a local fish store our feeder goldfish were shipped to us in very large plastic bags with 500 or so goldfish in each bag. Although we worked with a good distributor and didn't have many goldfish arrive at our facility dead, they were still quite stressed out from the shipping circumstances. Goldfish are tough and resilient but the conditions in which they are bred and shipped compromises their immune systems and leads to disease outbreaks.
Often times one can go to a pet store and view their holding tank of feeder goldfish and you will probably see at least one fish showing signs of some type of disease. Whether it be white spots, clamped fins, or red streaks on the goldfish it means that every fish in that water is exposed to that particular ailment. When hundreds of goldfish are shipped together in the same bag and when even more are maintained in the same holding tank it is inevitable that disease are passed on. In addition to all of the above mentioned details feeder goldfish often carry internal parasites which are not visible to casual observer. Once your predator consumes the goldfish with an internal parasite, they now carry that same parasite and may simply waste away over time.
In addition feeder goldfish are not a good means of nutrition on their own and the feeding of exclusively feeder goldfish can cause severe malnutrition and death. I can attest from all of my personal experiences that giving feeder goldfish to your predatory fish is not worth the risk in most circumstances. When I was young and a novice hobbyist I fed many of my large cichlids feeder goldfish, whereas now I do not. As a young teenager many of my large cichlids lived significantly shorter life spans compared to nowadays when I do not use feeder goldfish. With all of this in mind there are some circumstances that may warrant the use of feeder goldfish such as acquiring an exotic wild caught fish that is only accepting live food.
If a fish is only accepting live feeder goldfish then there are a few precautions that can be taken to significantly reduce the likelihood of disease transmission. The most vital aspect is to have a separate quarantine tank for the feeder goldfish in which they are introduced and acclimated. After being acclimated to the quarantine tank it should be dosed with an anti-parasite and/or anti-ich medication. If there are any signs of fungal or bacterial infections then the various tea extract medications on the market can be used accordingly with the other medications. I also use a medicated flake to feed the goldfish for at least 10 days and the medicated flake food is designed to rid the feeders of internal parasites.
Feeder goldfish should be in quarantine for at least 2 weeks with no signs of disease. The use of feeder goldfish for a predator that is only accepting live food should only be a temporary circumstance. The key here is getting the predator to elicit a feeding response in captivity and after the predator has been fed feeder goldfish a few times it should be fasted for multiple days. This will increase the likelihood of the predator accepting a non-living food item. In addition, if the predator is being really picky and taking a long time to learn to accept non-living foods, you can gut load your feeder goldfish. Gut loading is the process of feeding your already quarantined and disease free feeder goldfish a highly nutritional food that will pass on some nutritional value to the predator that consumes the goldfish. In my experiences I like to use high quality spirulina flakes and a color enhancing flake. Feed this to the goldfish a few days in a row and 10 to 15 minutes prior to offering them to your predators. With this method you are being sure to balance your predators diet versus only offering the feeder goldfish which does not have a very high nutritional value.
In the end one must remember to be very cautious in regards to using feeder goldfish to suffice their predatory aquarium inhabitants. If you are going to obtain feeder goldfish from a local fish store or pet store be sure to ask them about how the fish are shipped to them and if they medicate their feeder goldfish for diseases. If a store reports that they medicate their feeders and monitor them closely for disease then it would be worth it to pay a little bit more for healthier specimens. But again, the risks most often outweigh the benefits as a host of diseases can infect your prized specimens and their life expectancy can be cut dramatically short. If needed, the precautions above can be utilized to reduce the likelihood of disease transmission. Any questions, comments, or first hand experiences are welcome in the comments section!