A goldfish is the smallest fish belonging to the carp family. It is one of the most popular freshwater fish commonly held in aquariums and ponds.
Fishkeepers are oftentimes curious to know the gender of their goldfish, either for breeding or naming purposes.
Typically, a goldfish’s gender is virtually indiscernible when they are young. We have to wait until the fish matures to assess gender. Generally, it takes 9 to 12 months for the goldfish to reach maturity.
The following are ways in which you can tell the gender of your goldfish by being keen on the behavior and physical signs.
Identifying male goldfish
- Start by examining the fins, gills, and body of your goldfish. If white dots (tubercles) appear in neat rows on the scales of the body, the front fins or the gills, then your fish is male. Typically, the white spots will appear during the breeding season. Since you might have to wait for the fish to reach maturity before using this method. This typically takes 12 months, depending on the breed, health, and environment of the fish. Occasionally, male goldfish will not develop tubercles.
- The shape of the body is another way of telling the gender though it is not solely reliable when sexing goldfish. It is therefore advisable to add another factor into consideration as you come to a conclusion. Males typically look longer and leaner than their female counterparts of the same age and breed.
Identifying Female Goldfish
- Examine the vent of the fish located under the anal fin—where eggs and waste are released. The vent of females tends to be protruding whereas those of males tend to be concave and longer.
- The female appears shorter and rounder and is deeper-bodied so you can easily identify its sex from a side view. Male goldfish tend to look longer and thinner in the abdominal area.
- During the breeding season, The mating behavior during the breeding season should be checked out as well when it comes to sexing goldfish.
The male will be seen chasing around the female or even follow closely just underneath the female belly. This in return causes the female to be always on the run and could lead to torn fins in the process. The female also tends to be pushed either to the side of the tank/ponds or into the plants by the male to force them to spawn. It is important to note that in the absence of the female fish the male will still chase each other around so look out keenly. This is considered as the most accurate way of telling the gender in goldfish.
- The midline ridge of a female goldfish at the underbelly will be very faint or even not exist as compared to the male.
Maintaining the health of your goldfish will make gendering easier. This is done by ensuring they have clean water and well-fed, thus promoting regular spawning behaviour from your goldfish.
Of course, in your assessment of gender, you may want to use more than one factor.