Medaka can jump out of the rearing container when the water temperature rises too much or when it is surprised. Let's take measures.
When breeding indoors, there is almost no jumping out of medaka. It jumps out when it is surprised or when the water temperature rises too much.
Even if the room is exposed to direct sunlight or the amount of water is low, the summer water temperature may rise too much and fly out. However, in such a case, even if the pop-out prevention measures are taken, the water temperature rises too much and kills the killifish. The amount of water should be sufficient, and if it is exposed to direct sunlight, it will be necessary to make a shadow.
In the method of keeping a medaka for salad balls etc. at the table recommended in the Medaka's House, medaka often panic and jump out at first. Let's be careful not to surprise Medaka for the first 2 to 3 days.
Or, it is also possible to prevent jumping out of medaka reared at the table starting from fry. However, since fry requires sun light for growth, it is certain to start from a juvenile that has grown to about 1cm to 1.5cm under sunlight.
When rearing outdoors, most of the jumps occur when Medaka is surprised. It is especially important to be careful when it rains.
If the rain hits the water hard, Medaka will panic and jump out. To prevent rain from falling directly on the water surface, cover half of the breeding container and float water plants on the other half so that rain does not directly hit the water surface.
Also, when rearing outdoors, medaka may not be used to people and may be surprised when people approach it. For example, people often pass the side of the breeding container, and breeding the medaka so that they get used to it also helps prevent jumping out.
The best chance of getting used to people is the time of feeding. During feeding, you need to adjust the amount of food so that it can eat everything within 5 minutes. At this time, because people are looking at medaka for 5 minutes, it will understand that people gives food, then medaka gets used to people.
As feeding is the best chance for people to get used to them, let's feed them while watching the medaka for 5 minutes.
Column -Medaka does not jump-
The medaka will not jump if there is not much. River fish often jump in the evening to prey on insects on the water surface, but medaka does not have such a habit and basically does almost no jump.
Therefore, lids are not required for medaka rearing. The lid is required for the first few days until the medaka calms down. Once the medaka has settled down and is no surprise, no lid is needed.