February 28

Sarah Robertson

Get to Know the C123 Corydoras- Fun Facts and Care Tips

Corydoras elegans, a beautiful species of fish, is widely distributed and known to come in many color forms. Perhaps all of these variants are distinct species, although no study has yet been done to determine this. The Rio Nanay in Peru has fish with unique yellow-orange tinted fins, which distinguishes it from the rest. Some males (their dorsal fins are blotched with dark bands) have even rather brightly colored dorsal fins in old age. Anyway, this Rio Nanay variety has been assigned the code number C123 so that it can be identified in the aquarium trade.

C123 Corydoras species does best in an aquarium with a sandy substrate, some rocks for hiding, and some plants. It is a peaceful fish that does well in a community tank with other small fish. Cory Catfish are a social species that does best in a group of 5-10 fish, and they generally get along well with other non-aggressive tankmates. This fish is an omnivore and will eat most anything, but it is especially fond of live or frozen foods such as brine shrimp, daphnia, and bloodworms. When compared to other Corydoras, these fish are quite social and tend to swim peacefully in open water rather than staying close to the bottom. 

To learn more about keeping and caring for C123 Corydoras, read on!

Quick Facts about

  • Scientific Name : Corydoras(ln5) sp. (C123)
  • Common Names: C123, Gulfinnet Pansermalle (Denmark), Yellow Fin Cory, Peru Yellow Cory.
  • Distribution: Rio Nanay, Peru. Amazon River Basin, Upper Amazon.
  • Size: 45mm or 1.8
  • Diet: Omnivore, Insects, invertebrates, most sinking frozen & prepared feeds
  • Recommended Tank Size: 15 gallons
  • Lifespan: 5-7 years
  • Compatibility: Peaceful, excellent community fish
  • Water Temperature: 78-82F
  • pH: 6.0 – 7.5
  • Ammonia : 0ppm
  • Nitrite : 0ppm
  • Nitrate : <30ppm
  • Breed Type: Egg Layer

C123 Corydoras Care

The C123 Corydoras is a relatively easy fish to care for. These fish are very hardy and can withstand a wide range of water conditions, making them ideal for both beginner and experienced aquarists alike. Cory Cats are best kept in a group of 5 or more fish, as they are a social species that do best when living in close quarters with other Corydoras. A minimum tank size of 15 gallons is recommended for housing a small group of C123 Corydoras.

These fish are omnivores and will eat most anything, but they do seem to prefer live or frozen foods such as brine shrimp, daphnia, and bloodworms. It is also a good idea to supplement their diet with some sinking pellets or tablets as well. Cory Cats are known to be bottom feeders, so make sure that there is plenty of food available for them to scavenge.

For their proper care, it is recommended to do a 20-30% water change every week or two. These fish are very sensitive to ammonia and nitrites, so it is important to keep a close eye on your water parameters and perform regular water changes as needed.

C123 Corydoras Size

The length of C123 Corydoras is approximately 4.5 cm with a maximum of 5-6 cm.

C123 Corydoras Lifespan

The lifespan of C123 Corydoras is around 5-7 years, but some have been known to live more than that in captivity.

C123 Corydoras Appearance 

What makes this fish stand out is the bright yellow fins, especially on the males. This coloration is quite rare in Corydoras. Otherwise, they appear to be most like C. elegans with the dark brown body with silver white markings. The pattern on the animal's head is mottled, and then there are two more-or-less stripes running down its back to the tail. The dorsal and tail fins are yellow with horizontal dark bands and the caudal fin has less dark coloration. The remaining fins are also yellow.

Sexual Dimorphism

C123 Corydoras males have higher dorsal fins with dark bands and their dorsal fins are strongly orange colored, but only in old age. Females are generally plumper than males. Males typically grow to be around two inches, while females are slightly larger at half an inch; however, the latter tend to have heavier-set bodies.

C123 Corydoras Behavior 

This is a very active fish that loves to play. They are schooling fish, so they do best when kept in groups of five or more. They are peaceful by nature and get along well with other community fish. They swim all over the tank, often in groups of five or more.

They always prefer well-planted tanks. This will help them feel more secure, as they are constantly on the lookout for predators. They are bottom dwellers, So you will often see them swimming near the bottom of the tank or in and out of plants.

c123 corydoras

C123 Corydoras Tank Mates

Picking the right tank mates for your C123 Corydoras is important – not only do you want to choose fish that will get along well together, but you also want to pick fish that will compliment the unique look and personality of your C123. Here are a few ideas to get you started:

  • Tetras are a popular choice for tank mates since they are small, peaceful fish that school together.
  • Guppies are another good option since they are also small and relatively peaceful. Plus, their colorful fins add a splash of visual interest to the tank.
  • If you want something a little bigger, consider angelfish or Gouramis. Just be sure to choose a species that is known for being calm and social, as some angelfish can be aggressive.

A few other good tankmates for C123 Corydoras are:

  • Platies
  • Swordtails
  • Barbs
  • Rainbow fish

As always, it's a good idea to do your research before adding any new fish to your tank. This will help you ensure that everyone gets along and that your C123 Corydoras stays happy and healthy.

Bigger and more aggressive fish are not recommended as tank mates for your C123 Corydoras.

While choosing ideal tankmates, it’s important to keep in mind that every fish has its own unique personality. Some fish get along well with others, while some do not. It’s important to evaluate each fish individually and see how they interact with the others in the tank before making any decisions.

Play it safe by choosing fish that won't start any trouble and are generally easy to get along with. This will help lower the risk of aggression and stress in your fish tank.

C123 Corydoras Tank Setup 

The C123 Corydoras is a peaceful bottom-dwelling fish that does best in a well-planted tank with plenty of hiding spots. While setting up a tank for your C123, be sure to include:

A sandy substrate: The C123 Corydoras is a burrowing fish, so a sandy substrate is necessary to help keep its skin and fins healthy.

Plenty of plants: The C123 Corydoras is a timid fish that tends to stay hidden among the plants. Be sure to include a variety of plants, both tall and short, to give your fish plenty of places to hide. When choosing plants for your tank, be sure to avoid any that are known to be poisonous to fish. Some examples of safe plants include java fern, hornwort, and Anacharis.

Hiding spots: In addition to plants, the C123 Corydoras also needs hiding spots like caves or rocks. This will help your fish feel safe and secure in its environment.

Good water quality: The C123 Corydoras is a sensitive fish that requires clean, well-oxygenated water to stay healthy. Be sure to perform regular water changes and use a high-quality filter to keep the water in your tank clean and healthy.

Another important thing to consider is the water temperature and pH. The C123 Corydoras prefers a water temperature of 78-82 degrees Fahrenheit and a pH of 6.0-7.5. If you are unsure about the water quality in your tank, it's a good idea to have it tested by a professional before adding any fish.

C123 Corydoras Breeding

To breed your C123 Corydoras, start by getting a group of 6-8 fish and keeping them in an aquarium that's at least 20 gallons. If you have both genders, the male-to-female ratio should be 2:1. The next step is to slowly raise the temperature of the water over a period of 1-2 weeks until it reaches 83-86 degrees Fahrenheit. Then, you'll need to do a large water change of 50-70% and add in some moss or plants for the fish to lay their eggs in.

After the eggs are laid, remove the parents from the tank so they don't eat them.

C123 Corydoras Fry

The eggs will hatch in 4-5 days, and the fry will be free-swimming a week after that. You can feed them baby brine shrimp or crushed flake food until they're big enough to eat regular-sized food. Keep in mind that C123 Corydoras are slow growers, so it may take 6-8 months before they're fully grown.

C123 Corydoras Diseases

C123 Corydoras are generally hardy fish, but they are susceptible to some diseases. It is always better to prevent diseases rather than treat them. The best way to do this is by maintaining good water quality in your tank and performing regular water changes. You should also quarantine any new fish before adding them to your tank to make sure they are not sick.

If you think your fish is sick, the best thing to do is take it to a veterinarian or fish store that specializes in fish health. They will be able to diagnose the problem and give you the best course of treatment.

Some common symptoms of disease in C123 Corydoras include:

  • Loss of appetite
  • lethargy
  • Clamped fins
  • White spots on the skin or fins
  • Red streaks on the body or fins
  • Flashing (rubbing against objects in the tank)
  • Gill damage

Some of the common diseases that affect C123 Corydoras include:

Ich :

This is a parasitic infection that causes white spots to form on the fish's body. Ich can be treated with a variety of different medications, but the best way to prevent it is to maintain good water quality in your tank.

Hole in the Head:

This disease is caused by a build-up of toxins in the fish's system and can be treated with a variety of medications. The best way to prevent hole in the head is to perform regular water changes and use a high-quality filter.

Fin Rot:

This is a bacterial infection that causes the fish's fins to rot. Fin rot can be treated with a variety of different medications, but the best way to prevent it is to maintain good water quality in your tank.

If you find any of these symptoms in your fish, it's important to take them to a vet or fish store as soon as possible so they can be treated properly.

C123 Corydoras


How Big of a Tank Does a C123 Corydoras Need?

A full-grown C123 Corydoras needs at least a 15-gallon tank. If you have a smaller tank, you may need to upgrade to a larger one as your fish grows. The bigger the tank, the better.

How Many C123 Corydoras Should I Put in My Tank? 

The general rule of thumb is to allow 2-5 gallons (7.6-19 L) of water per fish. However, with corydoras, more space is always better. Because they are bottom feeders, they appreciate a longer and wider tank rather than a tall one. A 15-gallon tank is a minimum size you should consider for a small group of corydoras, and a 20-gallon tank would be even better.

What Kind of Food Does a C123 Corydoras Eat?

C123 Corydoras are omnivorous and will eat most kinds of aquarium foods, including flakes, pellets, and freeze-dried or live foods. To ensure optimal health, it is important to give them a variety of foods. For example, you could feed them flakes one day, pellets the next, and live or frozen foods once or twice a week.

How Often Should I Feed My C123 Corydoras?

As a general rule, you should feed your corydoras small amounts of food 2 or 3 times a day. However, it is important to adjust the amount and frequency of feedings based on the fish's activity level and appetite. For example, if your corydoras are very active and seem to always be searching for food, you may need to increase the amount of food you're giving them or feed them more often. On the other hand, if your corydoras are not very active and don't seem to be eating much, you may need to reduce the amount of food you're giving them or feed them less often.

What Can Live With C123 Corydoras?

C123 Corydoras are peaceful fish that get along well with other peaceful fish. In terms of tank mates, you can pretty much choose any fish that is roughly the same size or smaller than your corydoras. Some good choices include Tetras, Danios, and Guppies. Avoid keeping corydoras with larger, more aggressive fish, as they may bully or harass the corydoras.

Can C123 Corydoras Be Kept Alone?

While corydoras can technically be kept alone, it is not recommended. These fish are social creatures that do best when kept in groups. A group of corydoras will not only be happier and healthier, but they will also be much more active and interesting to watch. If you do decide to keep corydoras alone, be sure to provide them with plenty of hiding places, as they may become stressed if they feel exposed.

How Can I Tell If My C123 Corydoras Is Healthy?

A healthy corydoras is an active fish with bright colors. The scales should be smooth and the belly should not be swollen. The fins should be intact and the fish should be able to swim easily. If you notice any of these problems, it is a good idea to take your fish to a veterinarian for a check-up.

Final Thoughts

C123 Corydoras are peaceful, social fish that make a great addition to most aquariums. These hardy fish are relatively easy to care for, but there are a few things you need to keep in mind, such as their diet and tank mates. Because they are omnivores, it is critical to provide them with a variety of foods, as well as to modify the quantity and frequency of feedings based on the fish's activity level and hunger. It's advisable to pick tankmates for corydoras that are similarly sized or smaller. Larger, more aggressive fish may bully or harass them. All in all, with the proper care, corydoras make wonderful pets that will bring years of enjoyment to any aquarium enthusiast.

C123 Corydoras are susceptible to a few different diseases, the most common being infections of the skin and fins. These infections are usually caused by bacteria or fungi and can be treated with antibiotics or antifungal medications. If left untreated, these infections can spread to other parts of the fish's body and eventually kill the fish. So if you notice any unusual bumps, sores, or discoloration on your corydoras, be sure to take them to a veterinarian for a check-up.

C123 Corydoras are one of the most popular fish among aquarium enthusiasts since they are simple to care for and are fantastic pets. If you're looking for a peaceful, social fish to add to your tank, consider getting a few corydoras!

Sarah Robertson

I am a passionate blogger who also happens to be a fish keeping enthusiast. Writing about my hobby is something that I absolutely love to do, and it's no secret that my chosen topic is always centered around fish keeping.

Sarah Robertson

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