My fish is gone from its small, dirty tank. What happened?

All these fish can grow quite large. The loach would be the "smallest" at about 6 to 8 inches when full grown. The Oscars can reach lengths of 18 inches and the Texas cichlid and sharks can reach a foot in length. All these fish will require much larger tanks than the ones you have now. The three Oscars alone would do best in a 125 gallon aquarium MINIMUM. The others may thrive in 55 to 75 gallon tanks. To leave them in small tanks will cause stress, aggression and likely infection.

A pet store won't be able to take them due to disease risk to their stock, regardless of how healthy they are. You could advertise them as free to a good home on a buy and sell site. You can't just put them into a body of water as they wouldn't be used to it and would not survive. You don't necessarily have to keep them in a tank, even a large plastic box/ bucket would do.

Thank you for using Petco Pet Education Center, formerly Petcoach! It looks like the tank provides enough room for Speedy and Explorer to swim comfortably. Keep an eye on them, and move them into a larger tank if they get significantly larger or you notice signs of fighting or increasing ammonia levels in the tank.

Sorry for the problems. Intestinal parasitism can affect small fish. Please check water quality to ensure ammonia, pH, nitrates and nitrites are appropriate. Taking a fish to a veterinarian for identification of the parasite can lead to a treatment plan for the adults. Sometimes invertebrates (snails) are intermediate host for the parasites, and removing them can reduce the problem. Good luck.

Thanks for reaching out. Not sure how when the lights were turned on, the fish responded when it had no eyes. Could the corneas be cloudy? This could be due to trauma from an aggressive fish, parasitic infestations, or infections. A veterinary visit would be recommended. If the one has no eyes, it needs to be humanly euthanized as can not find food and will starve to death or succumb to infection. Continue to test water quality and correct any problems. Good luck.

This could be due to having a tank that is too small. 6 goldfish in one tank poses several potential issues. Ideally, 1 fish should have a 20 gallon tank with an additional 10 gallons provided per extra fish. This would mean they should be in at least a 70-75 gallon tank. The reason being goldfish produce a larger than average bio-load (wastes) that can quickly overwhelm a small tank and filter. Poor water quality can lead to stress and infection as well as behavioral issues. Depending on their sizes, the present tank could be overstocked leading to bullying and fin nipping. Check the water quality and chemistry. Use a home test kit or submit a water sample for testing. Most pet stores will do this for free or for a small fee. Aim for an absence (0 ppm) of ammonia and nitrites with a nitrate level of 20 ppm or less. Perform partial water changes, if indicated, to stabilize chemistry and maintain or improve water quality. Use only aged or conditioned water that is temperature matched to prevent further stress or shock. Goldfish are cold water fish and do best between 65 F and 72 F (18.3 - 22.2 C). Make sure the filter is rated for at least twice the volume of the tank. If possible, separate out the aggressive goldfish to a different tank to prevent further bullying and injury.

Thanks for your question about your fish, and congratulations on your new family members! I didn't see how recently the tank was set up, but there are a couple of things that could be going on. I would start by checking your water quality - any abnormalities in water quality can make fish have abnormal behaviors, and the water looks a bit murky in the photos you provided. There may be parameters that need to be addressed depending on what you find. If you do not have a water quality kit, they can be purchased at the pet store or an aquarium store, or you can take a sample of your water in for evaluation to these places as well. Some will charge a small fee for this service, just so you are prepared. Also, with recent tank set ups, it can be stressful for fish as they are in a new habitat. I would recommend keeping the light on for only a few hours per day to start, as the bright lights can be shocking for them (since fish don't have eyelids). Gradually you can increase the length of time that the lights are on so that you reach a cycle of 10-12 hours of light and 12-14 hours of darkness for them. I hope this gives you a place to start, and I wish you and your mom the best with the new pets!