Many people are interested in finding out the sex of their goldfish. You may want to know this to breed them, or even just not to call Giorgio your female goldfish. Establishing the sex of a goldfish is simple, but it can become difficult if you don't know what to look at. This article will highlight the physical and behavioral differences that will help you determine if your goldfish is a boy or a girl.
Steps
Part 1 of 3: Recognizing Females
Step 1. Notice if it has a fuller, rounder body
Females tend to have a larger and more rounded body than that of males of the same age and species.
- They also tend to have longer bodies, which is useful for identifying them by looking at them from the side.
- As breeding season approaches, females will begin to develop eggs, which could cause a bump on their flank, making them look asymmetrical.
Step 2. Notice if your anus is protruding
The anus of female goldfish is rounder than that of males, and tends to protrude slightly just before the breeding season.
- Viewed from the side, the anus appears as a small raised surface on the female's abdomen.
- In addition to the protruding anus, the female's anal fin may appear thicker than that of the male.
Part 2 of 3: Recognizing Males
Step 1. Look for tubercles
One of the indicators to tell if your goldfish is a male is the presence of tubercles (small white dots) on the gills.
- Usually the tubercles will only appear during the breeding season but, in older males who have therefore already lived many, the tubercles may be present all year round.
- Tubercles can also appear on the pectoral fins, head and scales on the fish's body.
- Keep in mind that, even if the presence of tubercles is a good sign to establish that it is a male, this does not necessarily mean that their absence places us in the presence of a female, since tubercles do not appear on all males..
Step 2. Notice the presence of a slimmer body
Males tend to have a leaner, longer and more tapered body than females of the same age and species.
Step 3. Note the concavity of the anus
The anus of males has an almost oval rather than round shape. It will also be concave rather than bulging out.
Step 4. Note the presence of a ridge
If possible, look at the belly of the fish to see if it has a crest: a line that goes from the pelvic fins to the anus. In females this line is rather bland or non-existent.
Step 5. Notice if he starts chasing other fish
One of the most reliable ways to identify males is to observe their behavior during the spawning season.
- A male goldfish will chase a female throughout the tank, sticking to her tail, until it touches her.
- The male will also try to push the female against the edge of the aquarium or against the plants, in order to force her to spawn.
- However, in the absence of females, male goldfish will chase each other, so it's a good idea to take both behavioral and physical traits into account when determining the sex of your fish.
Part 3 of 3: Evaluation Errors
Step 1. Understanding the differences between the sexes will only be possible with mature specimens, and this takes about a year
- However, maturity depends on the species and sex. Some types of male goldfish reach maturity after 9 months, while some females can take up to 3 years.
- Without a DNA analysis, understanding the sex of newborn goldfish is virtually impossible. If you want to increase the chance of having both male and female fish, the easiest way is to buy at least 6 fish of the same type. Statistically, there is a 98% chance that at least one is of a different sex than the others.
Step 2. Know that there is no surefire way to determine the sex of a goldfish other than observing its behavior during spawning season
Distinguishing male goldfish from female ones is really complicated, even the most experienced can be wrong. This is due to the fact that there are many exceptions to the rules:
- Some male goldfish do not have tubercles, but in some cases the females may have them. Some female fish will not have a protruding anus, while some males may have it.
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Also, some goldfish species don't follow the general rules. For example, some species (such as ranchu or ryukin) naturally have very thick and rounded bodies, which makes it impossible to determine their sex by observing their body shape.
Tell if Your Goldfish Is a Male or Female Step 9Bullet2 - In practice, it is better to identify a goldfish by studying multiple traits, rather than trusting a single characteristic.
Step 3. Keep in mind that these identification methods only apply to healthy, well-fed fish
Sick goldfish may not behave normally during spawning or may not develop gender-specific traits. Consequently, it is important to ensure that your goldfish are in good health (and this means ensuring they have good quality water and adequate fish food) before you can recognize their sex.
- For example, an unhealthy male may not develop classic tubercles during egg season, just as a sick female may not have a protruding anus.
- The shape of the body can also be misleading. A skinny fish could be mistaken for a male (as males are usually smaller), but it could simply be a malnourished female. On the other hand, you might say that a bulky abdomen is a sign that a certain fish is female, whereas the swelling could be caused by dropsy (an internal bacterial infection).
Advice
- Some goldfish enthusiasts also believe that males tend to be more vibrantly colored, and more active than females.
- Try going to a pet store and watching the bigger goldfish. It may help you to distinguish the differences more easily.
