Goldfish are one of the popular aquarium fish, and identifying the sex of a goldfish is an important skill for farmers. While goldfish have difficulty distinguishing sex during their juvenile years, as they grow, some traits become apparent that help us tell if they are male or female.
The alveoli of a goldfish are the organs that help it absorb oxygen in the water. The alveoli of male goldfish are usually more prominent, while the alveoli of females are relatively flat. By looking at the shape of the alveoli, farmers can make a preliminary judgment about the sex of the goldfish.
The gill cover is a part of the body of a goldfish and is one of the key points of gender identification. Male goldfish usually have more convex gill opercules, while females have relatively flat gill operculums. This trait becomes more pronounced as goldfish reach adulthood, helping keepers to distinguish their sex.
As the goldfish matures, the male goldfish usually become more slender, while the female is more plump. Additionally, some goldfish varieties may exhibit color changes during the breeding season, with males presenting more vibrant colors to attract females. By observing these changes in body size and color, farmers can also make a preliminary judgment about the sex of the goldfish.
Male goldfish may exhibit more agitated and active behavior during the breeding season, and they may chase female goldfish to show off behavior. Observing the behavior of goldfish, especially during the breeding season, can provide additional clues to determine their sex.
After making a preliminary determination of the sex of the goldfish, the farmer can also confirm the sex of the goldfish through more professional methods, such as identifying the shape and location of the cloaca. By combining these methods, farmers can more accurately identify the sex of goldfish, which is helpful for scientific management of goldfish breeding and conservation.