Ranchu Goldfish

Ranchu Goldfish

General Information
Scientific Name Carassius auratus
Minimum Water Size 30+ gallons (113.56+ liters)
Ease Of Care Easy
Average Lifespan 30 years
Temperament Peaceful
Approximate Adult Size 10 inches (25.4 centimeters)
Water Parameters 65-75 degrees Fahrenheit (18.33-23.89 degrees Celsius), 4-20 KH, 6.5-7.5 pH
Diet Omnivore
Native Region Asia


The goldfish is one of the most commonly known fish in the world due to it being well known as the "starting aquarium fish" when it truly is not. Goldfish come in a mixture of different varieties, some might be special due to location restrictions and other reasoning. Due to their nature, they are cold water fish and must be kept in waters that are not tropical. Many fish keepers will tend to keep this species mixed with other tropical fish, when it reality they are hurting both fish in the end. Goldfish are common diggers and will dig up any plants, move gravel and sand to other parts of the tank in both their pond or aquarium environment.

Goldfish are commonly used in harmless experiments that can test if fish are able to learn tricks, what conditions fish can live under, and other various science experiments across the world. The first record of this fish being domesticated and kept as either a pet of as a food source dates all the way back to the years 618-907. These fish are commonly found in Asian history along with their songs, paintings, and other types of media sources throughout the years.


The male goldfish will chase around the female goldfish, and they will have a breeding ritual where they may dance around each other, flash fins, or get very close to one another. Once the water parameters and temperatures are perfect for them, the female will start to lay her eggs all over the substrate, leaves, rocks, or anywhere that she feels safe. The male will then get close to them and release his sperm, which will fertilize the eggs. A female goldfish can release up to 1,000 eggs at a single time, where the hatching period is roughly 48-72 hours depending on the temperature of the water. Once the eggs have hatched, they will tend to stay at the bottom of the water column hidden away and will have no parental care from either of the parents. It will take anywhere from 5-10 days for the fry to be fully developed and be fully free swimming. Since goldfish are adapted to living in conditions where many of the other fish are bigger than they are, the fry will grow exponentially for the first few weeks in order to outgrow those other fish that may have just laid their eggs during the same timeframe.

Sadly due to the way that some goldfish have been bred by various breeders, many are unable to reproduce (both male and female counterparts). If you find yourself being unable to have any eggs hatch, any eggs being laid, and all of the water parameters are within the conditions listed above, try getting another male or female goldfish. Since goldfish do not care whom they mate with, this method works for the general population that have issues with breeding. Another issue might be the age of the goldfish, since they tend to only breed after a year or two of age. Since many aquarium stores do not know the age of the fish, you can always wait a few months and see if anything changes.


Goldfish will eat a variety of foods, including crustaceans, insects, and any plant matter. Since they will eat any live plants, it is strongly advised to not keep them in any planted aquarium (in ponds they will eat some plants however not be able to keep up with their growth rates). Many of the goldfish brand food has more carbohydrates than it does protein, which can lead to goldfish getting bloat more often than not.

Since goldfish do not have a stomach that can store food, it is strongly recommended that you feed them smaller meals multiple times a day rather than one big feeding that is only given once a day. They are also known as opportunistic feeders, which will not stop eating if there is any food source present in front of them. Unfortunately this means that they can be overfed quickly easily which may block their internal organs, and result in death.