How to Identify and Care for Red Cap Oranda Fish

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How to Identify and Care for Red Cap Oranda Fish
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Fish make pretty pets, and watching them glide around in their tank can be quite relaxing. They can also be quite interactive. While they'll never play fetch with you or curl up on your lap, red cap orandas do recognize their owners and will often show off a bit for them when receiving attention. These sweet little goldfish grow to about 10 inches long and live 10 to 15 years or longer with proper care.


Red cap oranda identification

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The red cap oranda (Carassius auratus) is a particular species of goldfish and, like all other goldfish, originally descended from carp. This attractive little fish has an oval body shaped like an egg and metallic-looking scales for a bit of shimmer. Red caps have white bodies and a bright-red growth atop their heads called a wen. The wen starts to form when a fish is between three and four months old and will continue getting bigger until he is about two.


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Red caps also boast long, flowing white tails and fins that fan out beautifully when the fish stops swimming. These fins are attractive and make identifying red cap fish easier. Because of their similar coloration and wens, red caps are often mistaken for lionhead goldfish. Lionhead have no dorsal fins, however, and red caps do.


Choosing a home

If desired, you can house your red cap goldfish in a clean, outdoor pond. The pond must be a minimum of 2 feet deep and hold 250 gallons or more. If you live in U.S. Department of Agriculture zone 4 or colder, skip the pond or bring your fish indoors for the winter.


When choosing an indoor tank, opt for one that holds at least 20 gallons of water. If you want to get more than one oranda, start with a 20-gallon tank and then add 10 gallons for each additional goldfish. Goldfish require lots of oxygen, so each fish needs plenty of breathing room.


This need for oxygen also dictates the best shape for a fish tank. Ideally, you should provide the largest water surface area that you can. As such, rectangular tanks with wide tops make a much better choice than round bowls or octagonal tanks.

Get ready for moving day

Once you have a tank, you'll need to get it ready for your new fish. Start by lining the bottom of the tank with gravel, unless you plan to use an undergravel filter. In this case, the filter goes in before the gravel. You can use any filter you like as long as it provides mechanical, biological, and chemical filtration, but undergravel filters blend in better and improve the tank's aesthetics.


When adding decorations to the tank, choose only those with rounded edges. Sharp edges can cut into your red cap's wen, leaving it exposed to infection. Decorations that add air to the water are also a good choice, but live plants aren't. Goldfish are diggers, and your fish will happily uproot any plants she finds in her tank and may eat them.



After decorating, add water to your tank and then install the heater and a thermometer. Wait at least 24 hours before adding fish to the tank. While you're waiting, make any adjustments you need to get the water temperature between 65 and 72 degrees Fahrenheit with a pH level of 6.0 to 8.0.


Getting the right fish

When you're ready to buy a red cap oranda, pick out a healthy one. Avoid stores where you see dead fish floating atop their tanks as well as any tanks that seem to have a tint to the water. This may indicate that the fish recently required medication. Choose one of the most active fish in the tank and choose specimens free of spots, discoloration, dull scales, or sores.

Meeting the neighbors

Goldfish are quite social and can absolutely share living space with other fish. There are, however, a few caveats. First, keep in mind that red cap orandas are gentle souls who don't do well with aggressive fish. Even mildly aggressive fish can stress orandas, so stick to super mellow roommates.

Note too that red caps are slow swimmers. When housed with faster fish, orandas fall behind at feeding time and may not get enough to eat. They don't do well in koi ponds for this reason, since koi are voracious feeders. The best companions for red caps are other egg-shaped goldfish like the black moor, ranchu, lionhead, bubble eye, and ryukin, as well as snails, who help keep the tank clean.

Care and feeding

Red caps are fussier about water quality than the common goldfish and require very clean water. In addition to running a filtration system, you'll need to perform biweekly water changes. To do so, remove about 30 percent of the water in your fish tank. Replace it with bottled water or tap water that you've either conditioned to remove chemicals or allowed to sit for 24 hours.


Feed your oranda three times a day, remembering to mix up his diet a bit. As omnivores, red caps enjoy both meat and vegetables. Feed your fish a high-quality flake food every day and then treat him to brine shrimp, bloodworms, and the occasional lettuce leaf. When feeding worms and shrimp, always provide frozen specimens so you don't accidentally introduce bacteria or parasites into his environment.

Watch the wen

Sometimes, the wen growing on top of a red cap's head can get too big. If it does, it will hang over her eyes and make it difficult for her to spot food. If this happens to your fish, consult your veterinarian about a wen trim. During this procedure, the doctor will anesthetize your fish to keep her still and comfortable and then remove the problematic portion of the wen.

The wen can also cause other problems. Due to its wrinkly, brain-like texture, the wen is prone to catching and holding on to any bacteria or dirt found in the water. You can usually avoid problems by keeping the tank clean, but consult your vet if you notice anything odd about your fish's wen like discoloration, swelling, or soreness. An infected wen may require treatment or even removal.

Health concerns

Red cap goldfish are generally hardy and do well with proper care. Illnesses can happen, however, and some are fatal if left untreated. Ich is the most common aquarium fish disease and is characterized by white spots on the fish that look like salt. To deal with ich, treat your fish tank with an ich treatment promptly, carefully following the directions on the bottle.

Unfortunately, most other fish diseases have a wide variety of causes. Swim bladder disease, for example, causes a fish to have trouble staying upright when swimming. It has numerous causes, however, including constipation, deformity, parasites, and poor nutrition. These multiple causes make it hard to know how you should treat the condition.

The best course of action is to watch your fish for signs of illness and put in a call to your vet or an experienced aquarist for help if you see any signs. This minimizes your risk of misdiagnosing the problem or taking improper steps to treat the issue. Signs of illness you can look for include:

  • Wounds and ulcers
  • Cloudy skin or eyes
  • Swimming sideways, upside down, or in circles
  • Parasites on fish
  • Loss of appetite



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