What is the Difference of Male and Female Cometfish

Six months ago I bought 9 cometfishes and keeping it in the water tank. Each one has 3 inches long when I bought, but now they have 4 inches long. I feed them 2 times a day with artificial food. They look pretty good because of their long tail and body color.

I often sit in front of the water tank just for look their activity. One day, I found a such interesting activity of my fishes. There are 3 fishes that chasing a fish continuously. The accident happened many times that make me little worry and ask to my self :"what actually happened?"

So I decided to looking for some information to answered my question was in the internet. I found that such activity is a mating behavior in Cometfish (also happened in goldenfish, Koki, and koi). Male cometfish usually chase female to get attention. Matting happen when famale gives attention to male. But, there is no matting when female don't gives attention. That information made me understand what actually happened in my fishes.

After that, appeared new question in my mind :"what was the difference of male and female Cometfish?" So I looked intensively to the fishes to found the different. After some times I found 2 signs to differentiate male and female cometfish.

Male cometfish has breeding tubercles when they are sexually mature.

The first sign is the appearance of spot in the gill cover (operculum). I browsed the internet and found that spot is called breeding tubercle. Male cometfish has many breeding tubercle in the gill cover but the female don't has it.

The second sign is cometfish body shape. Male usually looks more slender than female. Female cometfish produces eggs that make their stomach looks obese and less slender.

All of the signs above only happen in sexually mature cometfish. We can't see breeding tubercle and obese female in immature cometfish. The fish become sexually mature around 1 year of age but it usually takes another 2 years before their prime.

From the accident in my water tank, nowadays I become understand the difference of male and female cometfish. It is interesting to know male and female cometfish, so I can breed my fish in the future.